First off, been a while since I have been on here. Hello. My Dodge now has 38000 miles on it. Other than a weird issue with the dome lights only staying on for about 30 seconds before going off (even with the doors still open) the truck has been good to go. Fuel mileage in the Hemi has sucked from day one (13 MPG, crew cab, 4x4 Laramie). I have been hearing a lot of people going on and on about RP and Amsoil, somoe even claiming to get MPG increases. I am thinking about giving one of them a try. Have any of you tried both and found one to be better? Any MPG increase? I am talking about the engine oil, trans fluid, F&R diffs and T case. Hoping if I change them all, I might gain some mpg. Which one do you think I should try? Or should I just stick with Mobil1?

 

on the dome lights you can change how long they stay on up were the compass is go into the menu

 

i have worked in the oil fields for about five years and everyone without a question agrees that royal purple is the best motor oil around. This is the 15w40 for desiel motors and their hydraulic oil. I dont know about gas motors. I had an 06 2500 before sadly totaled it and now a 08 have run royal purple from the first oil change in both.

 

Hammer seen 3mpg's changing all fluids over to RP.

Lots of speculation on this very sore beaten topic. Both are top oils. Can't lose using either one.

 

Will check it out. maybe it got changed. Thanks.

 

In my Grand Cherokee, actually. Close to 3 anyway. That's running RP in the engine, both diffs & transfer case. I'm going to try it in the tranny & their radiator juice too, just to see.
Now granted, these gains are going from the conventional oil the previous owner used all the way to RP.
The truck is not getting any better mpg's or enough to really make a difference, anyway. It is running a bit smoother and the "Hemi Tick" is a good bit quieter. But that's going from Mobil 1 to RP...

 

Using RP in my 05 and sofar it's great, runs smoother etc.

 

A Amsoil user and happy with the performance, extended changes (5-6,000) and slightly reduced the tick. Big difference in the winter at start up however. As far a gas mileage, going 100% Amsoil, if I said anything greater than 1/2 mpg, I'd be a lie.

 

I use RP and have for year, I did see a 2 1/2 MPG increase using the old pen and paper method.. I did just read some interesting information about RP from a pretty good source so I think I'm going to give Amsoil a try and see what happens. Here is what I read, https://dodgeforum.com/m_1066882/tm.htm and this links you to the real meat of the story here, http://www.ls1.com/forums/showthread...ht=mobil+sarge

Now to be honest I don't believe everything I read but I have noticed that my RP is much more dirty when draining it than it did last year so I do have to wonder...

 

Heck come to think of it I just serviced my diff's and not 3K down the road my bearings went in the rear and the dealer replaced them all under warranty. The more I think about it I am going to change over to Amsoil!!!!! Every thing I read about it claims its better and much more consistent in formulation so I really don't have anything to loose by giving it a try. I will come back in a few months (40-50K) and let you know how it went...