Short answer
ATF+4 is Chrysler’s automatic transmission fluid, defined by Chrysler material standard MS-9602 and sold under the Mopar brand. Chrysler service guidance says ATF+4 is backward compatible with ATF+3, ATF+2 and ATF+, and recommends it where those older fluids were specified. Several newer Stellantis transmissions use different fluids, so ATF+4 is not universal across the brand.
Chrysler’s ATF lineage
Chrysler, now part of Stellantis, has written its own automatic transmission fluid standards for decades. The sequence went ATF+, ATF+2 and ATF+3, each with its own MS number. ATF+4, written to MS-9602, followed and became the recommended fluid for Chrysler, Dodge, Jeep and Ram automatics that previously used the earlier fluids.
A Chrysler service bulletin states that where ATF+, ATF+2 or ATF+3 was the recommended fluid, ATF+4 is now recommended, and that ATF+4 can be used to top off vehicles that used those fluids. It also says the older fluids should not be used to top off a transmission filled with ATF+4.
What changed with ATF+4
Owners and technicians commonly describe ATF+4 as keeping friction properties similar to ATF+3 while moving to a more durable base oil. The result is a fluid that resists breaking down in service better than the older fluids it superseded.
Chrysler’s bulletin is clear on one point that’s easy to miss: switching to ATF+4 does not change the service interval. Follow the interval already in effect for the vehicle.
When a Chrysler product does not use ATF+4
Some Stellantis vehicles use transmissions sourced from or designed with other suppliers, including eight- and nine-speed automatics, and those specify their own fluids. Certain older Jeep transmissions built by Aisin also had different recommendations. The owner’s manual and the fill-tube or dipstick marking take priority over any general rule.
ATF+4 is an automatic transmission fluid. Manual transmissions, transfer cases and axles in the same vehicle often call for different lubricants.
Reading “ATF+4” on a multi-vehicle bottle
ATF+4 is a Chrysler trademark. Fluids not licensed by Chrysler commonly say they are “for use in” or “suitable for” ATF+4 applications or list MS-9602. Those are claims by the blender. Check the manual, then check the current product data sheet before choosing.
Frequently asked questions
Can I use ATF+4 instead of ATF+3?
Chrysler service guidance says ATF+4 is backward compatible with ATF+3, ATF+2 and ATF+, and recommends it where those were specified.
Can I top off ATF+4 with ATF+3?
No. Chrysler’s guidance is not to use the older fluids to top off a transmission that contains ATF+4.
Does every Ram, Jeep and Dodge automatic use ATF+4?
No. Several newer eight- and nine-speed automatics and some older transmissions use other fluids. Check the owner’s manual.
General maintenance information. Always follow your vehicle or equipment manufacturer’s requirements and the current product data. Questions? Email [email protected].