the book calls for ATF 4
it is backwards compatible, meaning if your owners manual reads ATF 3
the ATF 4 is compatible
Type 9602/ATF+4 fluids was that it would have the same frictional characteristics as ATF+3. The paper explicitly states that this was because new clutch materials would not be introduced for this fluid and it had to be backwards compatible with ATF+3. Graphs in the paper show that the friction coefficient of fresh ATF+3 and ATF+4 is essentially identical, but as the fluid ages ATF+4 retains the “as new” coefficient while ATF+3 degrades.
The paper noted that one alternative was to use synthetic Group IV base stock, which are even more expensive than the ATF+4 solution, which provided Group IV style performance from Group III stock. ATF+4 meets strict low-temperature, oxidation, and volatility performance requirements and relatively low cost
Manufacturers can make ATF+4 fluids, but to use the trademarked ATF+4 name in their compatibility list, they must have their fluids tested and licensed by Chrysler engineers, and must use Lubrizol in their formulations. Licensed fluids are periodically sampled from stores to assure quality