What Is CVT Fluid And Is It The Same As Transmission Fluid?

A modern car's CVT or Continuously Variable Automatic Transmission is as complex as a conventional gear-driven automatic gearbox. However, it functions differently than a standard automatic and has no pre-set gear ratios thanks to a unique cone-shaped pulley system. Instead of having a predefined set of gears, a CVT delivers "infinite gear ratios" to match the driving requirements, helping the vehicle save fuel while providing smooth and almost imperceptible "gear shifts."

Then again, the inherent smoothness of how a CVT operates has given it a not-too-stellar reputation among enthusiast drivers. Despite this, it remains a popular option for carmakers and auto buyers primarily for the enhanced fuel economy that a CVT delivers. Similar to planetary automatic gearboxes that require a specific type of ATF or automatic transmission fluid, CVTs require a fresh diet of CVT fluid to maintain optimum performance, and this is where most of the confusion begins -– particularly when servicing is due.

CVT fluid is a fully synthetic lubricant formulated to meet the crucial demands of vehicles equipped with a continuously variable transmission. Like the oil inside an internal combustion engine or conventional automatic gearbox, the CVT fluid is the lifeblood of a CVT transmission. CVT oil provides consistent lubrication of internal parts like the pulleys, belts, or chains to minimize friction and wear.

It also helps dissipate excess heat that could otherwise destroy the gearbox when it overheats. The absence of physical gears means CVTs are more likely to overheat under extreme driving conditions (towing, climbing hills, etc.), so they need the right oil that deals with excessive heat. Conventional ATF oil has similar anti-wear and anti-foaming additives as CVT fluid, but the latter has long-life friction modifiers to prevent slipping and jerking without promoting wear.

As with any automatic transmission, using the correct fluid could spell the difference between many years of trouble-free operation or costly downtime. Using the correct type of CVT fluid when draining or topping up your car's CVT gearbox is cheap insurance against expensive repairs. Remember to check the owner's manual to find the best type of CVT fluid for your ride.

No, ATF is different from CVT fluid. The inherent differences in the engineering, construction, and operating principles of a CVT require a different type of fluid than what you'll find inside a dual-clutch or conventional automatic transmission. CVT fluid has unique anti-wear additives and modifiers to combat friction while maintaining the correct viscosity as the miles pile up, helping the CVT and its internals cope with intense pressure, heat, and friction.

Like all fluids, the CVT oil inside your gearbox will not last the life of your vehicle and is susceptible to breaking down. And when it does, irreparable damage will occur. Some manufacturers have eliminated the transmission dipstick, making it impossible for car owners to check the condition and level of the CVT fluid as the vehicle ages. The owner's manual will tell you when to inspect, flush, and replace the CVT oil, but most carmakers will recommend a CVT oil flush every 30,000 to 60,000 miles.