I ran Royal Purple MaxATF in my truck for about 6 months. It did seem to shift a tad better at first but with in a month it was getting worse.
I do BELIEVE my TC was already starting to bake before I ever put the Royal Purple in my transmission so I'm NOT saying that RP baked my trans!
But when the truck was in the shop I did some research on if I should put the RP back in or go with something else after they were done.
Dave reminded me that up until a few years ago no one made a ATF+4 for Dodge except Dodge. It was a proprietary formula. That got me thinking OK who does Dodge allow to make their special secret formula then?
First thing I learned was that the Mopar ATF +4 is a full synthetic right from the factory. Our automatic transmissions never run a dino oil in them.
Next thing I learned is some brands are licensed to re-brand: just use the same formula as Chrysler and some are licensed to blend: modify the formula with in specifications.
The most interesting part I learned...is neither Royal Purple nor Amsoil (Tommy / Ray you find me proof that Chrysler has licensed them to reblend and I'll change this) are on their list.
http://www.centerforqa.com/licensedatf4brands.html
Advance Auto Parts ATF+4®
Carquest ATF+4®
Castrol ATF+4®
Chevron ATF+4®
Citgo Transgard ATF+4®
Coastal ATF+4®
Conklin ATF-Xtra Plus ATF+4®
Formula Shell ATF+4®
Great Wall ATF+4®
Havoline ATF+4®
MAG 1 ATF+4®
Mobil ATF+4®
Mobil Super ATF+4®
Mopar ATF+4®
MotoMaster ATF+4®
NAPA ATF+4®
Northland ATF+4®
O’Reilly ATF+4®
Parts Master ATF+4®
Parts Plus ATF+4®
Pennzoil ATF+4®
Petro-Canada ATF+4®
Quaker State ATF+4®
Ravenol ATF+4®
Sinopec ATF+4®
Super Tech ATF+4®
Texamatic DC ATF+4®
Ultramax ATF+4®
Valvoline ATF+4®
I'm sticking with Mopar ATF4+ from now on.
Hate to tell you this but Mopar ATF is not Full Synthetic, its made from Group III crude oil base stock. If you want 100% Synthetic ATF then use Amsoil Universal ATF.
Below is from the Allpar website and I quote:
"The use of Group III base oils is probably the leading cause for ATF+4 being a more expensive fluid than ATF+3 (which according to the paper uses a Group II base oil).
Contrary to popular myth, one of the stated goals of 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. Lubrizol developed a new shear-stable viscosity index (VI) improver specifically for ATF+4.
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 — believe it or not."
From Allpar about oil base stock:
Group I base oils can have a mix of different hydrocarbon chains, with relatively little uniformity; these oils are the least refined. They are usually not used for autos.
Group II are the most common base oils in “dino juice,” with good performance in most areas except cold temperature viscosity.
Group III are called synthetic, and have high molecular uniformity and stability. Group III oil bases are used in most synthetic oils.
Group IV are chemically engineered stocks, arguably with the highest performance and longevity.