I have always used mobil 1 syn, until a month ago when i got it changed i used AMSoil for the first time, my question is, since amsoil is supposed to be so great, is it possible that my engine might idle 50-100 rpm lower with this stuff in? it seems to me that since i added amsoil it idles lower and i can hardly ever hear it idle at stop lights like i used to be able to...is this normal and does it have to do with the oil at all? thanks!!!

 

dude turn the radio down first lol! never heard of a complete quite engine before
i would be very careful about mixing oils and changing brands without talking to the engine MFG. i had heard and seen horror stories about Syn and regular oils also a few about all the different add in's like lucus, slick 50 and others.
gumming or a plugged filter would not be nice. hemi or not!
there is alot of science that goes into oil's and Syn's so i would say: Get the Fact's first
i work for BP and mixing is a NO NO!

 

I would not worry about having the Amsoil in the motor after having the Mobil1. As far as the idleing question, it is computer controlled and should not idle lower because of just an oil. One caveat though, after I drive my truck around for a while with no load on the engine (No A/C) and I pull up to a stop light, it will idle closer to 500rpm's when it typically runs at 600-625rpm's. If it isn't warmed up completely, it will idle slightly higher or if the A/c is running. I consider the Hemi to be a fairly quiet motor once warmed up.

 

You are right Osteo. My 4.7 does the same thing. I run Mobil 1 Syn.

 

Both are the best synthetic oils out. I would stick to one brand just to keep it simple. Theroreticallc it should'nt matter as long as the weight is the same. I run Amsoil in my Harley and Mobil1 in all my other toys just because of availability at my different shops.

 

I run the Mobil 1 because I can find it easily at Wally World. You have to search for an Amsoil dealer.

 

...those who know....Royal Purple...