Popular Transmission Fluids Ranked Worst To Best

Transmission fluid is designed to protect gears and clutch packs while allowing for smooth shifting. Much like engine oil, transmission fluid needs to allow for the right amount of friction, fight against overheating, and protect moving parts from wear, although automatic transmission fluid (or ATF) also acts as a hydraulic fluid, allowing the transmission to pressurize the fluid and initiate gear changes.

It's recommended to exchange the fluid at least once or twice over the life of a vehicle as fluids will break down with time, heat, and usage. Folks comfortable with a little DIY (and, likely, a small mess) can even perform the procedure at home. Just be sure to check the vehicle's manual, as recommended service intervals vary. For example, a 2021 Ford F-150 suggests a fluid exchange at 150,000 miles, while a 2003 Honda CR-V falling under the "severe service" category requires an exchange at 30,000. And it's equally important to use the right fluid — every brand has several different formulations, but not all are compatible with all vehicles. Even vehicles with "lifetime" transmission fluids aren't exempt – many technicians suggest changing these "lifetime" fluids before the warranty is up on the transmission — often around 50,000 miles.

While the simple choice is to use manufacturer-branded fluids like Motorcraft, Mopar, and Honda, these aftermarket brands often offer better formulas with additives that improve performance and longevity.

One of the first results on Amazon when searching for ATF is Triax, which is odd considering how many better known transmission fluid brands the online superstore carries. While Triax's Multi-Purpose ATF holds a 4.6 star average over nearly 200 Amazon reviews, many of those reviewers reveal that they've only tried Triax because it was on sale, or because Amazon's algorithm suggested it to them. Not a lot of Triax lifers, it would seem.

A Google search for reviews of Triax transmission fluid reveals many forums with folks asking if others have any opinions or reviews of the product, and many specifically mention that they found Triax fluid on Amazon. But most replies share one opinion on the product — it's a transmission fluid that's not really well-known, with a number of errors in its compatibility list, and at $16 a quart on Amazon it's nearly double the price of several of the more well-known and trusted brands.

Far more recognizable is the one in the bright yellow container. Pennzoil has been around since 1913, and while it's among the best motor oil brands, Pennzoil's transmission fluid isn't as widely beloved. One reason for that is a lack of supply on Amazon — only 19 reviews and a 4.6 star average for Platinum ATF+4 and just over a hundred for Pennzoil Synchromesh Manual Transmission Fluid aren't exactly overwhelming numbers, and listings of Pennzoil's other offerings are few and far between.

Searches on the websites of other retailers bear similar results. Advance, AutoZone, and O'Reilly list neither Pennzoil's automatic nor manual transmission fluid options, despite the brand manufacturing a number of formulas of ATF alongside its Synchromesh manual transmission oil, and all those parts stores carry Pennzoil's motor oils. While Walmart does carry several varieties of Pennzoil transmission fluid, they are only available for shipping, and they are nearly all only available in packages of six.

As with many of the brands available, Castrol began its life as a motor oil manufacturer, in London way back in 1899. Its practice of adding castor oil to lubricants to thin them out allows for effectiveness during cold starts. Castrol's focus on small engines and heat protection led to a series of great '90s ads showing the effects of viscosity and thermal breakdown on an engine. Thermal breakdown is a product of motor oil or transmission fluid overheating and degrading, which can alter the product's viscosity and ability to coat engine parts. That, in turn, can lead to severe engine and transmission damage.

Today, Castrol offers nearly a dozen formulas of ATF, from a universal fluid that's compatible with automatic and CVT transmissions to specific options for import vehicles, high mileage cars, and import rides. Reasonably priced and well rated on Amazon, Castrol remains one of the leaders in engine and transmission lubrication.

Winners of a frankly obscene amount of awards in its native Germany, Liqui Moly is mostly known as a racing brand, but their products are also used in daily drivers. The company's name comes from its first product, a can of liquefied solid lubricant molybdenum disulfide. Sold in US Army shops, the solid lubricant adhered to engine parts even in the event of complete oil loss — a concern when one's vehicle is being shot at, especially for Air Force pilots.

Liqui Moly's unique package design helps it stand out on the shelves, but its wide variety of additives and products have helped it grow. The company makes several kinds of transmission fluids that are compatible with brands all over the world. Of course, its European heritage drives Liqui Moly to focus on makes like Fiat, Volkswagen, and Mercedes-Benz, but with over 20 transmission and gear oils to choose from, Liqui Moly covers all bases at a high, but not unreasonable, price.

Mobil is a company that's been around over 140 years, and its trademark font and red Pegasus logo are familiar sights at gas stations and service shops around the world. Mobil's long history began as part of John Rockefeller's Standard Oil, adopting the Mobil name after several reorganizations and rebrands in 1966.

Mobil 1 topped SlashGear's ranking of synthetic oil brands, and Mobil lands solidly in the middle of the transmission fluid rankings as well. Eight different formulations are available, with a couple of Mobil's full-synthetic options (ATF and LF ATF HP) falling under the Mobil 1 umbrella and its familiar silver bottle. Many of Mobil's transmission fluid offerings have garnered over a hundred reviews on Amazon, and all of them average over four stars.

While not the overwhelming favorite it is in the synthetic oil category, Mobil offers a quality product at a good price. Unfortunately, strong competition forces Mobil's transmission fluid offerings to the middle of the pack.

Founded in 1927, Pentosin has been a partner of many auto manufacturers. More than 25 automakers use Pentosin lubricants for their "first fill," meaning the products Pentosin sells to customers are likely the same fluids those customers are draining out of their European vehicles.

Pentosin is best known for its synthetic CHF 11S hydraulic fluid in the green metal canister, or its pinkish-purple Pentofrost coolant used in many European vehicles. But the company also manufactures motor oils, brake fluids, and, yes, a well-regarded series of transmission fluids as well.

Like Liqui Moly, German company Pentosin focuses on European makes like Audi, Jaguar, and Alfa Romeo, and their products include several ATF formulas designed for specific Mercedes-Benz, Audi, and Volkswagen transmissions. Many American and Japanese automakers are covered as well, allowing loyal Pentosin customers to run the quality German fluid in all their vehicles. The very specific niche transmission fluids Pentosin offers push the lubricant manufacturer higher in the rankings.

AMSOIL is an American company specializing in high-quality lubricants. The company deals exclusively in synthetics. AMSOIL's transmission fluid standards are different than other companies, as it chooses to sort its ATFs by benefit (fuel efficient, multi vehicle, racing applications) rather than by brand compatibility.

AMSOIL recently introduced 1 quart Easy-Packs to many of its product lines, swapping a traditional bottle out for a small pouch with a nozzle attached to minimize waste and spillage. AMSOIL is also one of the few brands to carry an ATF Flush kit, ensuring a better and safer clean than a simple spill-and-fill. At around $12 to $18 a quart, AMSOIL's transmission fluid options aren't cheap, but they aren't prohibitively expensive either — and they are very well reviewed on the site and several oil review sites as well.

AMSOIL provides a lot of data to back up its claims. The company's blog goes over the results of a number of tests its Signature Series Synthetic AFT went through, including a 180,000 mile severe-service test run in a fleet of Las Vegas cabs. Oxidation resistance, gear wear protection, friction properties, and more were tested, and the AMSOIL ATF that came out of those taxis often tested as well, or better, than specifications required for new MERCON V or ATF+4 standards. While it's tough to find on Amazon, AMSOIL transmission fluids are available directly from the manufacturer at a comparable, and often lower, price.

Like AMSOIL, Red Line is another "boutique" fluid and additive manufacturer, less widely known but very well regarded among drivers. Red Line's history as a reliable oil for both racing applications and automotive enthusiasts boosts its transmission fluids near the top of our rankings. Some say these higher priced fluids aren't worth the extra cost, but Amazon's reviews say otherwise.

Red Line Synthetic Oil got its start as a lubricant manufacturer for the racing industry back in 1979. Today, the company makes over a hundred fluids and additives, from motor oil and antifreeze to two-stroke engine oils and chain lube. Red Line offers eight different variations of transmission fluid. Formulations are available that work with nearly every make and model out there, as well as a high-temp ATF for towing or RVs, two drag racing focused fluids, and dual clutch and CVT options. Most of these are about $15-25 a quart thru Amazon, and they all sport high ratings and great reviews. Even the drag racing formulations are available via Amazon, which is a little surprising considering the lack of Pennzoil or AMSOIL products on Amazon's site.

Like all of Royal Purple's products, its Max ATF has its defenders because of the company's history and reputation, as well as the high quality lubricants it produces. Even though at nearly $21 a quart it's nearly triple the cost of some of the other highly-rated transmission fluid offerings, reviewers insist the high price of Royal Purple Max ATF is worth it due to the many benefits. Max ATF is compatible with dozens of manufacturer-specific automatic transmission fluids — everything from Ford and GM to Suzuki and Toyota. So whether a vehicle just needs a top off or a full transmission fluid exchange, buyers can feel confident in their purchase.

Royal Purple claims that its blend of additives in its Max ATF provides smoother shifting, better fuel economy, reduced shudder, greater torque hold capacity, and a reduction in heat and wear in the transmission. The company also backs those claims up with a limited warranty, offering to replace both the defective lubricant and the parts damaged by said lubricant. Between great reviews on Amazon, a good warranty, a wide spectrum of vehicle compatibility, and a slew of benefits, it's no surprise that Royal Purple's product lands near the top of reviewers' favorites.

Another widely popular brand, Valvoline is one of the most affordable options of transmission fluid. While that doesn't make it bad by any means, it does invite scrutiny when put against fluids that go for twice the price. Fortunately, Valvoline passes those tests with flying colors. As a company that's been in business since 1866, Valvoline's reputation in the world of automotive lubricants includes its transmission fluid options. One of only a few brands on our list with over a thousand ratings on Amazon, Valvoline's low price and great rep go far in making it one of the more recommended transmission fluids.

Like many other fluid manufacturers, Valvoline offers several different variations on the product. Whether it needs to be compatible with DEXRON-VI, Mercon V, an import, or a hybrid, Valvoline offers a specialized formulation. If a multi-vehicle option is needed, Valvoline's MaxLife Multi-Vehicle ATF is suitable for use in 95% of all light-duty vehicles in the U.S. Valvoline prides itself on being the #1 automatic transmission fluid brand, and it's also the best selling transmission fluid on Amazon. Pair those facts with over six thousand reviews of MaxLife ATF, and thousands more on its other transmission fluids, and it's obvious why Valvoline is the best-known brand.