wanted to have my transmission and rear differential oil changed wanted to use Royal Purple then was told Amsoil was better for that just curious on yalls takes,....

 

I have used Royal Purple for 6 years now and I think it's the best out there. I have a 2004 Pontiac GTO that me and a speed shop called SNL Performance used my car and changed all the fluids to Royal Purple, we did a baseline dyno and after, I gained 12rwhp and 9rwtq and droped trans temps by 26 degrees and rear end 19 degrees really good stuff, plus it's made in Texas!

 

That'll make it sell itself

 

It's all a matter of opinion and taste. They are both great oils....it's like the Ford is better than GM argument. Personally, I would go with which one is less expensive as, like I said, they are both good.

 

I can vouch for RP synchromax- my tranny was hurting, made it better than new... powershifting at the track damaged the 2nd syncho, refused to shift at all over 4k, often blocked in normal driving, reqd doubleclutching...
best thing was immediately after the change, the shifter would fall into third slick as can be- like a new tranny...within a hour of driving 2nd was just as good as third, that was 2 years ago(had put up with the balky second for a year, oil was clean when drained, no metal or anything- the RP really works!)

amsoil might be as good or better, but I'm sold enough to quit shopping brands

 

That sounds kickass

 

Do u do ur own fluid change?

 

yeah, tranny is easy(on a lift anyways) just drain, get a few feet of that cheep hardware store clear tubing that will fit over the tapered squeezebottle thing RP uses for a screwcap, point down and squeeze the bottle to squirt it into the tranny...if you dont have access to a lift, I think the squeeze bottle/tubing would work with ramps even- but the level might be hard to judge if the car isnt flat...

I havent changed the diff oil yet, but filling my mark vii(also a 8.8) after a bearing change was easy using same squeeze bottle/tubing...note- limited slip differentials REQUIRE a 'friction modifier' with standard oils. my mark I didnt use it at first and you couldnt turn a corner without wheelspin or drivetrain chatter...not sure if RP/Amsoil requires it or not...the fomoco stuff was like a little 4 oz can, just a small amount, but its definitely not a option to skip it with regular oils

 

I'm planning on going Royal Purple in the tranny & rear end of the Shelby, and RP in the tranny of the Cobra. The Cobra can be a little clunky and buzzy here and there so I'm looking forward to what RP will do after reading lots of testimonials. Sticking with Mobile 1 in the engine though...

 

I got it done today with amsoil they talked me into it so we'll go from there lol

 

Oil discussion threads are a slippery slope (no pun intended). I'm a member of an '80's motorcycle forum and it's one of the forbidden subjects that will get people to hate you. The right oil is crucial in a 30 year old bike that eats cams for breakfast, but I guess they've been there, done that enough for their lifetimes.

But this is the conclusion they have from all of that discussion: Is it the correct viscosity or weight? Is it and does it need to be synthetic? From a reputable company? If you answered yes to all 3 questions then you're fine.

I've been running Mobile 1 full synthetic in both engine and diff since I got the car brand new, and I drive it HARD. Car has been fine for 6 years.

 

They talked me into amsoil. Is that bad?

 

I have no experience with amsoil so I couldn't say. But I've heard a lot of people say they use it, so it can't be total crap. Doing a google search on "amsoil review" might help you out.

 

Will do