ATF+4
Use in 48RE, 68RFE, 42RLE, 545RFE, 65RFE, 66RFE, and most Chrysler/RAM RWD automatics.
When to use: Stock spec for nearly all 1998+ Chrysler/Dodge/RAM transmissions.
Wrong-fluid consequence: Using Dexron VI in a 68RFE causes immediate slip and TCC shudder. ATF+4 has different friction modifiers - they are NOT interchangeable.
Aisin AW-1
Use in Aisin AS69RC (HD Cummins) and Aisin AS68RC. Specialty fluid.
When to use: Required for HD trim RAM 2500/3500 with Aisin transmission option.
Wrong-fluid consequence: ATF+4 in an Aisin = warranty void, immediate slip. Aisin AW-1 only.
ATF+4 is sold as Mopar ATF+4 or aftermarket equivalent (Valvoline MaxLife, Castrol Transmax). For warranty work use Mopar-branded. For shop rebuilds, aftermarket equivalent is fine.