How to keep your passenger car engines running smoothly

Today’s hardworking automotive engines need maximum protection against high-mileage wear, corrosion, and oxidation. From engine and gear oils to greases and transmission fluids, choosing the right lubricant to match every job is critical to achieving peak performance from your passenger car engines.

Our guide offers practical ways to protect and maintain all types of passenger car engines. Learn how to select oils and lubricants that will keep your automotive engines motoring on for thousands and thousands of miles.


Protect your vehicles’ engines with the right oil

All engine oils have many “jobs”. To simplify: An engine oil’s primary job is to provide sufficient lubrication to protect against the heat and friction caused by the moving parts inside internal combustion engines. However, not all engine oils are the same, and it’s vital to know which one is best suited for each job.

Engines that are properly maintained with the correct oil type will run smoother and last longer. But choosing the right oil can be complicated. Engine type and age, climate, and driving conditions all impact the wear and tear of automotive engines. Understanding the different engine oil types, specifications, and additives will help you select the best oil that matches the needs of each vehicle you service.

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1. Full Synthetic Engine Oil

Today’s conventional engine oils are quality products made from refined crude oil. In comparison, modern full synthetic engine oils are created in a variety of ways ranging from severely hydroprocessing select crude stocks in order to precisely control the size and shape of base oil molecules to laboratory designed complex chemical compounds. Full synthetic oils are engineered to increase the performance of today’s more precision built and hotter-running engines as well as to meet fuel efficiency standards and emissions regulations.

Advantages of Full Synthetic Oil

Better protection

Full synthetic engine oils are made from a petroleum base oil that is purer than a conventional crude product. Fewer impurities mean that the oil doesn’t break down as quickly and protects your engine longer than conventional engine oils or even synthetic blends. Using full synthetic motor oil results in better fuel efficiency, more horsepower, and improved wear protection.

Stable viscosity

An engine’s parts are constantly moving at high speeds, creating heat and friction. Full synthetic motor oils are engineered to retain viscosity, to resist extreme heat and to still flow quickly in winter temperatures, allowing your engines to run smoothly year-round.

Turbocharger protection

Turbocharged engines are designed to improve performance and fuel efficiency. However, that improvement comes at a cost:  higher temperatures. Because these engines run hotter and often have very tight oil passageways, they require a low-viscosity engine oil that can flow quicker and still withstand the heat and friction generated by a turbocharger shaft spinning at 200,000 rpms. Full synthetic engine oils are the best-suited to perform at high temperatures, protect against thermal breakdown, and retain viscosity under these extreme conditions.

Cleaner engines

As oil flows through a vehicle’s engine during combustion, deposits form. Deposits from conventional oils can turn into sludge that builds up in the engine, reducing efficiency and lifespan. Synthetic engine oils contain chemical detergents and other additives that resist the buildup of deposits. Cleaner engines run smoother, more efficiently, and longer than dirty, congested engines.

Kendall GT-1® Max with LiquiTek®

Our full synthetic automotive engine oil designed to provide maximum engine protection for gasoline-fueled and flex-fuel passenger cars and light trucks under all operating conditions.

Full Synthetic Engine Oil - Euro

European cars require different oils with different specifications than cars manufactured in the U.S. This is due to the European Union’s stricter emissions standards, the more frequent use of diesel engines, and longer service intervals.

European emissions standards

The EU more strictly limits carbon dioxide (C02) and carbon monoxide (CO) emissions than the U.S. Because of this, European OEMs use more diesel engines. Diesel engines emit less CO2 and CO and provide better fuel economy but emit more nitrogen oxides and particulate matter. To counteract this, diesel-powered European cars are equipped with filters and catalysts to reduce tailpipe emissions.

Oil components, such as sulfated ash, phosphorus and sulfur (known as SAPS), can shorten the lifespan of diesel engines and emissions devices. Therefore, it is imperative to choose synthetic oils formulated specifically for European vehicles that contain lower SAPS levels to protect emissions-control systems.

Longer drain intervals

While in the US and Canada, the traditional 3,000-5,000 mile oil change still exists, European automakers recommend longer oil change intervals – from 10,000 to 15,000 miles. Longer drain intervals require a robust synthetic oil capable of protecting against wear, deposits and sludge for the duration.

OEM recommendations

Each European OEM’s recommendations and specifications vary slightly from one another. Overall, European OEM engine oil specifications tend to be stricter on different performance characteristics than in the US and Canada. These specifications require technology delivered exclusively by full synthetic oils.

Kendall GT-1 Euro

Our premium quality, full synthetic, full-SAPS motor oil is designed for high-performance European gasoline engines.

Kendall GT-1 Euro+

Our premium-quality, full synthetic, low-SAPS oil specifically designed for high-performance European diesel engines.

2. Synthetic Blend Oil

Just as the name implies, this type of oil is a mixture of synthetic base stocks and conventional crude-based oil. Synthetic blends provide some of the performance advantages of a full synthetic at prices more closely comparable to conventional oils.

Using full synthetic oil costs about 30% more than using a synthetic blend. While conventional oils will only last about 3,000-5,000 miles between oil changes, full synthetics can last up to 15,000 miles (sometimes more). Synthetic blends fall somewhere in the middle at about 7,500 miles. Therefore, using a synthetic blend provides a step up in protection without breaking the bank.

Kendall GT-1 Synthetic Blend Oils

Our family of premium synthetic blend automotive engine oil provides technologically advanced engine protection for gasoline-fueled and flex-fuel passenger cars and light trucks under all operating conditions.

Kendall GT-1 High Performance with LiquiTek

Our high-quality, part-synthetic automotive engine oil designed to provide excellent engine protection for both turbocharged gasoline direct injection, conventional gasoline-fueled and flex-fueled passenger cars and light trucks under all operating conditions.

Kendall GT-1 Elite with LiquiTek

Our premier quality, part-synthetic automotive engine oil designed to provide outstanding engine protection for both turbocharged gasoline direct injection, conventional gasoline-fueled and flex-fueled passenger cars and light trucks under all operating conditions. Offers the same protection levels as GT-1 High Performance, but with an even more robust combination of additives and a quality base oils to offer consumers another step up in quality at a price below that of a full synthetic.

Synthetic Blend Oil - High Mileage

High mileage oils are formulated to overcome the added engine stress conditions of older vehicles and engines that have been driven for 75,000 miles or more. High-mileage vehicles are prone to cracked seals, oil leaks and/or oil burn-off. In response, specialized oils formulated for high-mileage vehicles include additives that compensate for these old age symptoms, reducing leaks and inhibiting oil combustion.

Kendall GT-1 High Mileage Booster

The industry’s first oil supplement that, when used as directed, results in a blend that meets current API and ILSAC performance standards. This pour-in solution helps reduce inventory cost and space.  What’s more? High Mileage Booster can be added to one of our full synthetic passenger car engine oils to offer consumers a truly exceptional level of protection.

Kendall GT-1 Endurance High Mileage

Our synthetic blend automotive engine oil specially designed for use in gasoline-fueled vehicles with more than 75,000 miles.

3. Conventional Engine Oils

All conventional engine oils are initially refined from natural petroleum crude. With so many manufacturers switching to synthetic motor oils, you may wonder if it’s ever okay to use conventional oils. Conventional oils still have their place and can provide good protection under the right circumstances at a lower price.

Conventional oils are typically used in older cars and those out of warranty and generally cost much less than synthetic oils. Those who are diligent about timely oil changes can use conventional oil, if the owner’s manual indicates it is permissible to do so. Additionally, more frequent oil changes can alert a mechanic to a serious problem developing in an engine.

Kendall GT-1 Motor Oil

Our conventional automotive engine oil designed for use in gasoline-fueled passenger cars and light trucks that do not require an ILSAC GF-6 oil for warranty coverage.

Our full line of Kendall Motor Oil is masterfully engineered with pure base oils and advanced additive packages. Kendall offers a full slate of products so that we can offer not only a quality oil, but also the RIGHT oil for your engine.


Here’s a checklist to consider for helping keep older cars going strong even longer

In 2020, the average age of vehicles on the road in the U.S. rose to 11.9 years, according to IHS Markit. The older the car, the higher the miles, and the more problems that can surface. Luckily, today’s cars are built to last. Most modern vehicles are designed to drive at least 150,000 miles over their lifetime, and some can get double that.

With the proper maintenance and protection, you can keep your high-mileage vehicles running smoothly and reliably for as long as possible.

What is a high-mileage vehicle?

If a car has 75,000 miles or more on it, it’s considered a high-mileage vehicle. High-mileage cars require more frequent maintenance than newer vehicles to keep them on the road and performing at their best.  Another thing to keep in mind is that a vehicle can be considered “high mileage” based on age, not just miles.  Vehicles reaching the 6-7 year old mark can benefit from the additional protection of Kendall GT-1 Endurance High Mileage even if they still have relatively low miles driven.

Here are the top six maintenance tips you can use to enhance the performance and reliability of your high-mileage vehicles.

1. Change the Oil

It should come as no surprise that this is the first thing we want you to keep in mind.  After all, if the engine is the heart of your car, then the oil is its blood. Therefore, the number one thing you can do to keep your high-mileage vehicles performing stronger for longer is to change its oil at the recommended interval and use a motor oil specifically formulated for high-mileage vehicles.

Why choose a high-mileage oil?

Just like any piece of machinery, as engines age, their internal components are subject to increased wear. High-mileage oils contain additives that take care of older engines, like seal compatible conditioners, antioxidants, detergents, and strong anti-wear or anti-friction additives.

Motor oils formulated for high-mileage vehicles have higher film strengths and viscosities that help them stay thick longer to better protect engine parts by eliminating the risk of metal-to-metal contact.

Kendall’s High Mileage Motor Oils are specially formulated with unique additives that may rejuvenate worn engines – this, in turn, may slow down the aging process of high-mileage engines.

Kendall GT-1 Endurance with LiquiTek

Our premium quality, part-synthetic automotive engine oil specially designed to provide excellent engine protection for both turbocharged gasoline direct injection, conventional gasoline-fueled and flex-fueled passenger cars and light trucks under all operating conditions. It also is recommended for use in lower-mileage vehicles, including new cars under warranty. It is part of the Kendall ILSAC GF-6 product line.

2. Oil Supplement

The engine is the heart of the car. To keep it performing strong, give it a boost of protection with an oil supplement made especially for high-mileage cars. Adding an oil supplement to your motor oil helps to eliminate deposit buildup and protect the engine from corrosion. A clean engine results in less vibration, quieter operation, and better overall performance.

Kendall GT-1 High Mileage Booster

Our high-mileage booster has been formulated exclusively for use with Kendall GT-1 motor oils to deliver the added protection from sludge and rust that high-mileage vehicles need. So, your engine gets the protection it deserves and the performance you rely on.

The High Mileage Booster is a unique concentrated blend of key additives, specifically tailored for high-mileage gasoline-powered vehicles. GT-1 High Mileage Booster increases resistance to corrosion and helps to improve engine cleanliness. It is part of the Kendall ILSAC GF-6 product line.

3. Transmission and other Fluids

Fluids keep a car’s components performing correctly. Regularly check the car’s coolant, power steering fluid, brake fluid, and transmission fluid. Top off any that are low. If any are particularly low, it could indicate a leak in a hose or tank. Replace fluids at the recommended interval.

The automatic transmission system is one of the most complex pieces of equipment on a vehicle and keeps your gears changing smoothly.  Maintaining the transmission fluid is important in high-mileage cars, because it keeps the system fully lubricated to avoid particle buildup and dryness that can lead to grinding, overheating, or breakage.

Kendall Versatrans® CVT Plus Fluid

Our premium quality, full-synthetic transmission fluid is specifically designed for use in passenger cars and trucks with belt- and chain-driven continuously variable transmissions as well as step-type automatic transmissions. It’s engineered with unique frictional properties required for protection and performance across all three types of transmissions. With more than 1 million miles of on-road testing, it delivers proven performance in CVT and step type automatic transmissions.

4. Battery Care

If the car’s battery isn’t performing, the car won’t start. Keep batteries clean by removing any corrosion from the top of the battery and around the cables with a metallic brushed dipped in a mix of baking soda and water. Open the cover and check that the electrolyte level is at one-half inch. Add distilled water, if needed. If you won’t be using the car for an extended period, such as while on vacation, attach the battery to a voltage maintainer to keep it charged.

5. Check and Replace Filters and Belts

Keeping air filters clean by and replacing them when they are too dirty or old will keep your engine running smoothly by helping to ensure efficient combustion. While you are at it, check belts and hoses for wear and replace any that need it.

6. Tires

Tires keep the car firmly planted on the road. Bald, under-inflated or over-inflated tires, and road hazards can shorten the life of your tires, damage the suspension system, and create safety issues. Make sure to keep tires inflated to the correct pressure and rotate them often to prevent uneven wear. Check tires for nails and other hazards and fix any needed repairs. Finally, be sure and replace your tires at the manufacturer’s recommended intervals.


How to get better mileage and performance from your vehicle

While today’s engines are more fuel efficient than those in the past, there are still many ways to enhance the real-world fuel economy you get from your vehicle. A car’s weight, aerodynamics, resistance, drag, and engine performance all impact gas mileage. Choosing a fuel-efficient car, using certain driving techniques, keeping up with proper maintenance, and selecting an advanced motor oil formulated to meet the challenges of today’s engines can help you save money by getting more miles out of each tank of gas.

1. Use a motor oil formulated for modern engines

The push toward better fuel economy and decreased emissions has forced OEMs to develop more fuel-efficient, less polluting engines, which require more advanced motor oils that are specifically formulated to meet their unique challenges.

Modern engine design

Increases in fuel efficiency and emissions standards have resulted in smaller engines that use modern technology to improve mileage and reduce greenhouse gas emissions.
  • Gasoline direct injection (GDI) and turbochargers work together to enable a smaller engine to generate the same horsepower as a larger engine.
  • Stop-and-start technology allows an engine to turn off and on automatically when driving in traffic or high-congestion areas.
  • Variable compression engines enable high efficiency and high performance of smaller engines at highway speeds.
These new engines require a more advanced motor oil that protects against the unique challenges presented by these engines, such as low-speed pre-ignition (LSPI), increased wear, and sludge formation.

ILSAC GF-6 and API SP standards

To meet these challenges, Kendall worked with the American Petroleum Institute (API) and original equipment manufacturers (OEMs) to develop a new standard: ILSAC GF-6 and API SP. These new standards went into effect on May 1, 2020.

GF-6 technology provides enhanced wear protection, prevents LSPI, improves fuel economy, and reduces carbon emissions in modern engines. It also helps OEMs meet their mandated targets for fuel efficiency and emissions.

Meet the most advanced Kendall motor oils ever

Kendall GT-1® Max Motor Oil with LiquiTek®

Our premium quality, full-synthetic automotive engine oil is designed to provide excellent engine protection for turbocharged gasoline direct injection, conventional gasoline-fueled, and flex-fueled passenger cars and light trucks under all operating conditions. It is especially recommended for vehicles operating at extreme temperatures or under severe driving conditions, such as towing heavy loads.

Kendall GT-1 HP Elite Motor Oil with LiquiTek

Our premier quality, part-synthetic automotive engine oil is designed to provide outstanding engine protection for turbocharged gasoline direct injection, conventional gasoline-fueled, and flex-fueled passenger cars and light trucks under all operating conditions.

Kendall GT-1 Endurance Motor Oil with LiquiTek

Our premium quality, part-synthetic automotive engine oil is specially designed to provide excellent engine protection for turbocharged gasoline direct injection, conventional gasoline-fueled, and flex-fueled passenger cars and light trucks under all operating conditions. It also is recommended for use in lower-mileage vehicles, including new cars under warranty.

Kendall GT-1 High Performance Motor Oil with LiquiTek

Our high-quality, part-synthetic automotive engine oil is designed to provide excellent engine protection for turbocharged gasoline direct injection, conventional gasoline-fueled, and flex-fueled passenger cars and light trucks under all operating conditions.

2. Perform regular maintenance

Dirty air filters, worn out spark plugs, and bad connections can all affect fuel economy. Following your vehicle’s recommended maintenance schedule will keep it running more efficiently and produce fewer greenhouse gas emissions.

3. Keep tires properly inflated

A very no cost approach to improved mileage, improved handling and overall safety is simply keeping your tires at the proper inflation pressure. Make sure you have your tires checked for inflation pressure at every service. If you have concerns, most tire stores will check your pressure and give your tires a quick visual inspection for free.

4. Skip the warm-up

The old adage of needing to ‘warm up the car’ before you drive it is a holdover from the days of carburetors and doesn’t hold true for today’s modern fuel-injected, electronically-controlled engines. Engines perform most efficiently at regular operating temperature, and the fastest way to reach that point is to drive right after starting the car.

5. Slow down

Driving habits like speeding, rapid acceleration, and braking waste gas. It can lower gas mileage by roughly 15 to 30 percent at highway speeds and 10 to 40 percent in stop-and-go traffic. Accelerate smoothly and anticipate the movement of traffic. Once up to speed, maintain a steady pace. Smooth acceleration, cornering, and braking also extend the life of the engine, transmission, brakes, and tires.

6. Remove roof racks, cargo boxes, and bike racks

Vehicles often have attached racks and boxes to carry things like luggage, bikes, skis, and surfboards. At highway speeds, more than 50 percent of engine power goes to overcoming aerodynamic drag. Carrying things on the roof or the tail hitch increases drag, increasing fuel use and lowering fuel economy. Consider removing roof racks, cargo boxes, and bike racks from vehicles when they aren’t in used to cut down on unnecessary drag and improve mileage.


Keep your vehicles’ gears shifting smoothly with the right fluid

The transmission is one of the most important – and complex – systems in a vehicle. It is responsible for literally making a car move by receiving the power from the engine, converting it into torque, and transmitting this rotational power to the wheels.

Transmission repairs are notoriously one of the most expensive and complicated repairs a vehicle owner can face. Therefore, keeping the transmission in good shape and using the right transmission fluid is critical to the safe and efficient operation of any modern vehicle.

How does a transmission work?

The transmission uses a series of gear ratios to keep a vehicle’s engine spinning at an optimal rate (neither too slow nor too fast), while simultaneously providing the wheels with the right amount of power they need to start, move, and stop the car.

The transmission acts like a power switchboard for the car: It increases torque to accelerate away from a stop, prevents the engine from working too hard at highway speeds, and disconnects the engine power from the drivetrain to allow a car to idle without moving.

Pillar Page Banner How does a transmission work

There are 4 types of transmissions

Manual Transmission

The simplest and oldest type of transmission is the trusty manual. The driver controls the gearbox by using a foot-controlled clutch to engage and disengage the engine from the wheels and a manual gear shifter to change the gears.

Automatic Transmission

While manual transmissions are mechanically simpler, automatic transmission are easier to use. Instead of the driver changing gears with a clutch and gear shifter, an automatic transmission uses a highly complex torque converter and a series of computer-controlled gear sets, clutches, and brakes to automatically shift gears up and down. The complexity, number of moving parts, and computer system needed for automatic transmissions can lead to expensive repairs, if not maintained properly.

Automated Manual Transmission

Like a manual transmission, an automated manual also employs a mechanical clutch. However, the clutch is automated using electronic, pneumatic, or hydraulic controls. Sometimes referred to as a “Direct Shift Gearbox” (“DSG”) or a “Sequential Manual Gearbox” (“SMG”), this transmission allows for either fully automatic forward gear shifts or manual shifts through the gear selector or through buttons or paddles on the steering wheel. A Dual Clutch transmission is an example of this type of transmission.

Continuously Variable Transmission (CVT)

The CVT is similar to an automatic transmission, but it operates using a completely different mechanism. The CVT doesn’t have gears at all — instead, it uses a system of belts and pulleys to produce an infinite range of ratios. The car’s computer decides how to adjust the pulleys to create the optimal ratio for the particular driving situation.

Pillar Page Banner manual Transmission

What does transmission fluid do?

In order for your transmission to work properly, it can’t have any of its metal parts grinding against one another. Similar to motor oil, transmission fluid acts as a lubricant between the transmission’s moving parts to facilitate smooth operation and to keep the transmission lubricated, clean, cool, sealed, and most importantly, transferring power.

Typically, transmission fluid needs to be changed every 30k-100k miles, depending on manufacturer recommendations. It will need to be changed more often on cars driven in high-stress conditions, such as frequent stop-and-go city driving, towing heavy loads, or driving up and down hills regularly.

How to choose the right transmission fluid

Since the transmission is one of the most complex systems in a vehicle, choosing the correct fluid is critical to preventing damage and ensuring the best performance and fuel economy. Today’s modern transmission fluids are typically blended with synthetic base oils to offer better performance, with improved resistance to heat, cold, oxidation, friction, and shearing. Here are the most common types of transmission fluids and what makes them different:

GM DEXRON®/ MERCON® V (Ford) / ATF+4® (Chrysler)

    • These automatic transmission fluids are the most common on the market and were designed and licensed exclusively by GM, Ford, and Chrysler. These fluids are formulated for the newest transmission technologies in today’s modern cars. They also can be used in many imported vehicles, according to manufacturer recommendations. All three include friction modifiers, which reduce the friction in lubricated parts.
    • Our full-synthetic, low-viscosity transmission fluid is approved for use in passenger car and light truck automatic transmissions that require a Ford MERCON LV or GM DEXRON-VI fluid. It also is recommended for use in Toyota vehicles where a Type WS fluid is specified, and in many newer import vehicles.
    • Our high-quality transmission fluid is recommended for use in all domestic and import vehicles no longer under warranty where the OEM previously specified a GM DEXRON®-III H or Ford MERCON® fluid.

Multi-Vehicle Synthetic Transmission Fluid

Multi-vehicle transmission fluids are becoming more and more popular. They were designed for a wide range of automatic transmission types. While not licensed by any specific auto manufacturer, they are designed to provide superior performance and protection. They are formulated with the latest additive technologies and typically use synthetic base oils.
  • Kendall VersaTrans ATF

  • This premium quality, part-synthetic transmission fluid is specially designed for use in automatic transmissions in most passenger cars and light trucks. It has been extensively field-tested for use in most North American vehicles and in a wide variety of European and Japanese vehicles.

Continuously Variable Transmission (CVT) Fluid

More manufacturers are using CVT transmissions in new cars due to their exceptional fuel economy. CVT transmissions require specialized fluids that are formulated with the correct frictional requirements to ensure the belt or chain remains in contact with the pulleys without slipping. Because of this, CVTs require specialized CVT transmissions fluids, and not traditional automatic or manual transmission fluids.
  • Kendall VersaTrans CVT Plus Fluid

  • Our premium quality, full-synthetic transmission fluid is specifically designed for use in passenger cars and trucks with belt- and chain-driven continuously variable transmissions as well as step-type automatic transmissions. It’s engineered with unique frictional properties required for protection and performance across all three types of transmissions. With more than 1 million miles of on-road testing, it delivers proven performance in CVT and step-type automatic transmissions.

  • Kendall CVT Fluid

  • Our premium quality, full-synthetic transmission fluid is specifically designed for use in passenger cars with belt-driven continuously variable transmissions. It has been engineered to have the unique frictional properties required for use in this type of transmission.
    Our automatic transmission fluid engineers have been working to redefine the term smooth-shifting. As a result, our ATF products are all specifically formulated to ensure long service life and provide consistently smooth shifting performance. Plus, every product is extremely shear stable, and holds excellent oxidation resistance. Use Kendall for maximum anti-shudder performance, excellent low-temperature properties, and easier shifting in cold weather.
Kendall CVT Fluid


How to choose an automotive gear oil

Automotive gear systems, such as those in manual transmissions and differentials, have a tendency to engage in a lot of metal-on-metal contact, causing heat and friction which results in wear and potential component failure if not maintained properly. Using the right gear oil for each application helps protect these moving parts by reducing friction and transferring heat away from them.

What is a gear?

An automotive gear is a rotating toothed cylinder, which forms a mesh with another toothed machine part or gear and transmits torque. The gears can change torque, speed, and direction of the power source and are a critical component in an automotive drivetrain. Gears come in many designs, such as spur, helical, bevel, worm and hypoid designs.
KDL Automotive gear oil

What is gear oil vs engine oil?

Gear oil is a lubricant used specifically for automotive manual transmissions, differentials, transaxles, and transfer cases. It helps the drivetrain run smoothly and protects critical internal parts in a vehicle’s gear systems from wear and heat damage. Inadequate lubrication can result in scouring, corrosion, scuffing, and pitting of important drivetrain components. This deterioration can compromise a vehicle’s performance, and eventually lead to costly repairs.

Gear oil has a higher viscosity than engine oil. It is identified by its performance classification and its viscosity. The Society of Automotive Engineers (SAE) publishes a viscosity grading guide (J306) for gear oil, which is a different grading scale than the SAE’s engine oil scale (J300).

KDL gear oil vs engine oil

Gear oil API performance classifications

There are several automotive gear oil designations, but the two most common gear oil designations – Lubricant Service Designations for Automotive Manual Transmissions, Manual Transaxles, and Axles – are set forth by the American Petroleum Institute (API) for passenger vehicles:

API GL-4 classifies passenger car and light truck manual transmission lubricants and oils used in tractor gearboxes and spiral bevel gear final drives.

API GL-5 defines passenger car, light, and heavy truck and bus hypoid final drives where there is a large amount of sliding movement across the gears.

A number of automotive manufacturers require lubricants that meet their own in-house specifications. Mercedes-Benz, GM, Ford, Volvo, and others have specifications for the gear lubricants to be used in their equipment, particularly where special warranty or extended lubricant service is offered.

KDL Gear oil viscosity

Gear oil viscosity

There are two common passenger vehicle gear oil viscosities.
The 75W-90 gear oil is used under extreme pressure conditions and can be recommended for limited-slip differentials and for use in colder climates. It is commonly used rear differentials, some final drives, and axles. The thick oil film formed this oil can withstand high temperatures.
The 80W-90 gear oil can be used in extreme pressure conditions and as a lubricant for some non-synchronized manual transmissions in heavy-duty trucks or buses.
Monograde Gear Oil
The SAE classifies gear oils suitable for operation at one temperature on a monograde scale. Gear oil meant for high ambient temperatures is designated by a single number, such as SAE 50. Higher numbers indicate a more viscous oil.
Multigrade Gear Oil
Multigrade gear oils have additives that change their viscosity at different operating temperatures. These gear oils are labeled with a rating for the oil’s low- and high-temperature viscosity. For example, SAE 80W-90 gear oil has a low-temperature rating of 80 and a high-temperature rating of 90.

Types of gear oils

Rust-Prevention Gear Oils
Rust-preventing gear oils are petroleum-based or mineral-based and contain rust inhibitors. These gear oils come in two different classes: monograde and multigrade. Monograde gear oil is designed for use in “normal” temperatures while multigrade gear oil can be used at hotter and cooler temperatures. Rust-prevention gear oils protect and extend the life of gears running at higher temperatures and are best used in low-load gearboxes.
Extreme-Pressure Gear Oils
Extreme-pressure (EP) gear oils can be synthetic- or mineral-based. EP gear oils are commonly multigrade and contain extreme pressure, rust inhibitors and anti-foaming additives. These additives allow EP gears oil to protect highly loaded gear sets. High contact pressure of the gear tooth face can cause gears to wear quicker. EP gear oils help extend the life of a high load-bearing gear sets.
  • Our extreme-pressure, API GL-5, SAE 80W-90 automotive gear oil specially formulated to satisfy the lubrication needs of most limited-slip rear axles. It is friction-modified to help eliminate the stick-slip chatter associated with low-speed, high-torque operation of limited-slip differentials while turning corners with some passenger cars and light trucks.
Synthetic Gear Oils
Synthetic gear oils are frequently multigrade oils that are formulated robust additive chemistries. Thes gear oils can be used at extremely high or low temperatures. They prevents rust, foaming of the gear oil inside the gearbox, and wear of the gears. Synthetic oils are used in gearboxes that are run in severe conditions such as sub-zero environments, extreme heat, wet climates, and dusty or dirty conditions.
  • Our next-generation, full synthetic, fuel-efficient API GL-5 automotive gear lubricant designed for use in passenger car and truck axles with hypoid gear sets operating in extreme temperatures or under severe driving conditions.
  • Our full synthetic, API GL-5 automotive gear lubricant specially designed for long-drain service and extended warranty protection in passenger car and truck axles with hypoid gear sets.
Kendall Super Three Star


How using the right hypoid gear oil can extend the life of your vehicle

Hypoid gears are commonly used in automotive and heavy duty truck rear differentials where high torque and load handling is needed. Because these gears work under high pressure, gear oils that have been specifically designed to withstand and protect against these extreme conditions are recommended to extend the life of the hypoid gearsets.

What is a hypoid gear?

Hypoid gearsets are a type of automotive gear design. When you picture a gear, you probably imagine two rotating toothed discs that mesh straight against each other. This type of gear design tends to be noiser and, in automotive applications, inefficient. The hypoid gear design was invented to reduce gear-meshing noise and to provide greater torque and pressure handling as well as provide more durability.

Hypoid gearsets are fairly similar to spiral bevel gear setup, with the difference that hypoid gears have an axis that is non-intersecting and not parallel. In other words, the axis of hypoid gears are offset from one another. The basic geometry of the hypoid gear is hyperbolic, rather than having the conical geometry of a spiral bevel gear – kind of like a cross between a bevel gear and a worm drive. Therefore, the hypoid pinion is larger in diameter than an equivalent bevel pinion. This introduces a high degree of sliding motion on the gear tooth face of the pinion of a hypoid gearset and also increases the cosisitency of gear teeth intermeshing.

When are hypoid gears used?

Hypoid gearboxes are found in most of today’s modern vehicles. They are commonly used in rear axle differentials, where they transmit power from the driveline to the axle shafts. They are a type of spiral bevel gear with a left-hand spiral angle on the pinion and a right-hand spiral angle on the crown. This lowers the driveshaft away from the bottom of the vehicle, lowering the vehicle’s center of gravity, and in some cases, reducing interference with the interior space of the vehicle.

What is hypoid gear oil?

All vehicles require gear oil to provide lubrication in transmissions and axle differentials. Unlike normal engine oil, gear oil viscosity is generally much higher to Help combat the chances of extreme conditions squeezing a thinner fluid out and allowing gears to grind each other down.

Hypoid gearsets, by design, are under higher pressure than other types of gearsets. A sliding action of the gear tooth face is also introduced in combination with the rotational motion with a hypoid gearset that is not present in many other gear set designs. This elevated pressure and sliding action can cause the gear lubricant to be squeezed out from between the meshing gear teeth, causing metal-on-metal grinding.

Hypoid gear oils have been specially formulated to help protect these special types of gear sets.Hypoid gear oils can have higher viscosities just like other gear oils, but hypoid gear oils contain special extreme pressure and anti-wear additives that increase its resistance to breakdown under the high temperatures and mechanical pressure produced by the sliding surfaces of a hypoid gearbox.

When to use hypoid gear oil

As with all engine fluids and oils, regularly maintaining and changing hypoid gear oil can extend the life of a vehicle and its performance. Well-lubricated gears have less probability of pitting, breaking, or grinding against each other under pressure. Regularly changing gear oil removes wear material and other potential contaminates such as dirt and water. Not changing the gear oil can lead to accelerated wear of the gear set due to debris and potential rust and corrosion from water and oxidation byproducts.

  • Our next-generation, synthetic, fuel-efficient (FE) API GL-5 automotive gear lubricant is designed for use in passenger car and truck axles with hypoid gear sets operating in extreme temperatures or under severe driving conditions. It has been specifically formulated to provide improved fuel economy compared to typical mineral SAE 80W-90 or synthetic SAE 75W-90 gear oils.
  • Our multipurpose, API GL-5 automotive gear lubricant is specifically designed for use in passenger car and truck axles with hypoid gear sets. It also is recommended for use in some heavy-duty manual transmissions in trucks and buses.
  • Our synthetic, API GL-5 automotive gear lubricant is specially designed for long-drain service and extended warranty protection in passenger car and truck axles with hypoid gear sets.