I found this pretty interesting. I think I'll go with Mobil 1 over mopar next diff service.
http://www.syntheticoilhq.com/pdf/g2457-gearoilcomparison.pdf

 

Wow, pretty interesting. Glad I read this before I change my fluids next month.

 

I can see how it would be biased since it was performed by Amsoil, but informative none-the-less. Seems the Mopar fluid didn't perform well at all. I've always wanted to try the Amsoil fluid though, so I may give it a shot when I change my diff fluid.

 

I know for the longest time, Mopar had contracts with Champion Labs for their filters (good sh*t) and Valvoline for the fluids (also good ****) but it's my understanding that when Ceberus bought Chrysler from Daimler, they went to absolute low bid on everything and in many cases use multiple vendors. You never know who makes the filters or the fluids anymore...

 

Yeah I laughed at the end when I saw that. I'm not going to be using amsoil because of the potential bias. I was more curious about Mobil 1/royal purple/mopar. Looks like M1 is the safer bet.

 

I use Lucas HD conventional in the rear diff, my aftermarket LSD specs conventional. Change it every 15k miles. Royal Purple in the front and I change it every 30k, basically every other time I do the rear...

 

Further proof the Royal Purple is not the best oil. I was always amazed at how many people swear by it and often pay more for it.

I use Mobil 1 because it's easy to find and it's made by a company with more money then anybody else in the running. Their lubricants are used in aerospace and high dollar machines and i have never heard anything bad about it. In my opinion, their is no need to buy any other brand for gear lube and engine oil. But if they dissapeared tommorow, i would go with another top end company and be fine with it.

As for Amsoil, i used them for a long time when i had my turbo diesel. Never had any issues and never heard anything negative. This test might be biased but it would not change my opinion on them. Great oil and a great company.

I know brand loyalty is a big thing. But think about this, have you EVER heard of anybody having a rear end failure or engine failure blamed on the oil when it was changed at the correct interval with the proper grade from a reputable company? I have'nt. Use Mobil 1, use Amsoil, use Royal Purple or use Valvoline and don't worry about. They are all great quality and i don't believe that any one of them is going to give you so much more protection over another that you will ever even notice. To me, people who argue that (as an example) Mobil 1 is not as good as Royal Purple for engine oil are simply looking to argue about things. You will never convince me that so long as i stick the proper change intervals that one brand will give me better protection and power then another.

 

Yep, maintenance interval is a LOT more important than what brand you go with IMO. Now I used Mobil 1 for probably 15 years until I stepped in doo-doo on a sale of Royal Purple (talking engine oil here) and it quieted down my "Hemi Tick" noticeably. Went back to Mobil 1 and the tick got louder. Valvoline Synpower for some reason also quieted the tick about as much as the RP. I pretty much use Valvoline now.
This is NOT a bash of Mobil 1 by any means, I've NEVER had an engine problem due to oil - EVER. But just based on the tick, I changed...

 

Well, it's signed in front of a notary! It has to be true!!

I've used RP for years, no "HEMI Tick" and got a little better mileage to boot. Use it in the engine and diffs. Stick with factory fluid for trans.