i've been wondering about this so i figured i would put it out there...my jeep always had regular oil pressure and it would increase at higher rpm and settle a little under 40psi at idle just like normal. THEN i put royal purple 10w30 in her and and (not only did it smooth things out throughout the entire rpm range, i have a 5sp) but it made my oil pressure spike to 65-70 when i get on it and at idle it just sits right around 60. it is not until i idle for a 5 minutes or so does it even begin to go back down to 40. now i know i our oil pressure sensors aren't known for accuracy but has anybody else experienced this? and i am thinking that maybe ,just maybe, royal purple might just be to crazy of an oil for my old tired I6. i mean c mon what oil is purple?

 

please do a search on Royal Purple! you will be draining it tomorrow and using it to get your next bonfire going! Thats what i gathered from my research and my opinion too.

 

is that so man? i'm doing a search right now

 

could you elaborate a little...ive been looking it up and only found that its basically the best thing since sliced bread.

 

ive just read that it lubricates everything in your engine 5x better then conventinal oil. What is all your opinions and what about synthetic oil and high mileage oil.

 

i did some searching and i agree with the last two posts...i mean i've gone through two cycles of royal purple now in my xj and i really do like it don't get me wrong...i just thought it was kind of fishy what it does to my oil pressure which is why i started this thread...the only explanation i have for this is royal purples "dry protection" which means that it always leaves behind a protective film or something and this may be the reason...also i pay 8 buck a quart here in new jersey

 

it bugging me i cannot find the thread i was looking for. what i did remember was high zinc concentration is what our 4.0s like. I guess its a horse apeace. You either love it or hate it. If i can find one instance that someone had a problem with a certain product (specailly oil) i will shy away. check out amsoil 10w 40 with zinc. or rotella seems to be one of the top pics.

 

What do you guys think about high mileage oil is there any "ACTUALL" difference between regular oil and high mileage.

 

yea from searching around i've already heard enough that i'm going with amsoil or rotella, it seems to be the general consensus. as for my royal purple, i just put it in so i'll give it another couple grand or so (i'm a 2500 miles kinda guy lol) then i'll go with one of the two. i guess its just like rustysoffroad. i've heard such horror stories from people and then i've heard positive things (i personally like them alot!!) PS i did see a thread on here too that said something about how high zinc and i think phosphorus levels are good for the 4.0s the guy seemed like he knew what he was talking about too lol

 

yeah i'd like to know the difference too, because i know we all have high mileage in our xjs

 

My baby has over 180k miles on her and i want her to live long

 

I'd really like to put the right stuff in my XJ, its not just an XJ...lol its my first car and for that reason alone I need to make sure she runs until....well forever. So If maybe we could get a vote? I dont really know much about oils, the do's and dont's and I really wish I did. So any knowledge on the topic is appreciated. As for that Royal Purple stuff, are the other oils listed in here as expensive? Can I pick em up at pepboys...or is this an online purchase?

 

i'm pretty sure amsoil is less expensive than royal purple, i've never seen anything more expensive that RP and to help answer your question i started this thread with RP in my engine and after like an hour i've changed my mind about it and am switching to amsoil for my next change

 

can't speak for the GC's, but I ran it in my 3g Eclipse for about 3 changes and noticed no change it operation. Now their gear lube (rp) for the trans made a world of diff, shifted and ran smoother.

 

i hear nothing but bad stuff about all there oils , some guy i know tryed there gear oil in the rear of his race car and destroyed the rear in a weekend using that stuff