Gamble

I just bought my Z06 about a month ago. Its a 2003 and I've put Kooks Long Tubes and the Blackwing on it and I just changed my oil for the first time.

The car has 8,000 miles. I decided to run 20W-50 Amsoil High Performance oil. When I get on it WOT 1st and 2nd gear the Oil Pressure shoots to around 75-80 psi. The long tubes were just installed 2 days ago and I really started to notice the oil pressure shooting up... I've heard theres nothing wrong with having higher oil pressure? But then other people have said since my car only has 8,000 miles on it its not good...

Is this good or bad? Should I run a thinner oil? Should I have stuck with the owners manual on this one (10W-30)? Any and all information would be greatly appreciated.

Charlie

slowtan

I think the owners manual says 5W30 .. I am sure an expert will step in and say what it is but yes you are definately running too thick of an oil .. If you are running amsoil then 5W30 is ok .. I am running mobil one that is why I run 10w30 .. Mobil one thins out .. definately get some thinner oil ..

Inspector12

iTrader: (29)

Well my opinion is a little different. I think that what part of the country you are running in has a large part to do with the weight of the oil you should use. Here in Texas especially Houston I run the mobil 15W50 cause of our extremely hot weather etc. I would think that a 10w-30 or 40 would be just fine for just about everybody. Patman is the oil guru and knows a lot more about the specifics of oils and what works best I just use my own judgement however. But with that said most have stated not to run a thinck oil like 20w50. Personally do what you want if some one single person knew everything I don't think there would be a need for a forum like this you could just call "The MAN" etc. My car used to idle at 60 and under hard acceleration it would go to 75-80 and I was running a 10w30 at the time. This was prior to the rebuild.

ex-SS-ve

iTrader: (9)

75-80. that the press at idle now? you were running 5w30 at that time jeff?

NA$TY-TA

iTrader: (21)

TTT Patman???

Patman

20w50 is definitely not the way to go in an LS1 unless the car is used purely for road racing and you don't have an oil cooler.

But for a typical street driven LS1 which sees oil temps closer to 200F most of the time, a 50 weight oil is not a good idea at all.

I'm seeing closer to 50psi at full throttle in my Corvette while using Castrol 0w30 Syntec.

I'd recommend at least stepping down to a 40 weight oil and see how the oil pressure changes here. The LS1 tends to like oils that are a thick 30 to low 40wt oil (viscosity of between 11.5 to 13.5 cst at 100c)

jbuckweiser

I run Mobile-1 10w30 and oil pressure is 45-50@ idle and 60-70 above 1500. I wouldnt
take a stock guage reading as gospel, but readings do see a bit high. how about Idle?
Sometimes bigger isn't better. I wouldn't use that high of viscosity personally. GM has
a pretty good idea about what to use.

NA$TY-TA

iTrader: (21)

How about a built blower motor????? 20w 50 is what i run and my oil pressure is higher and right were i want it. With castrol 10w30 my oil pressure was wayyyy to low for my liking... 25-30 psi at idle.. with my Amsoil 20w50 it is right at 40 psi at idle and 60-65 psi at WOT. I was told by my engine builder to run a thicker oil with a blower setup....
I would like a straight answer to this question.... is the higher oil pressure hurting the motor????? Is there a set pressure we do not want to go over??
Thanks
Kyle

Gamble

Thanks Patman for the information and everyone else. I better just go with the what the Owners Manual says. You can never go wrong with that.

eallanboggs

iTrader: (1)

If your running a ported oil pump your pressure will be a little higher than stock, but since you bought this vehicle used and it has 8K on it you may not know if the pump has been swapped out.

Flawless02SS

iTrader: (9)

20W-50 is way too heavy of an weight. That will kill your stock oil pump. Better go with 5W-30. Experts say always go with the owner's manual and if anything go lower than what it says.

onehardmaro

I use amsoil 10w30 and have really high oil pressure. Start up idle around 60 and accleration around 75-80. Warm up idle around 50 and accleration about 60-70. What would be harmed by high oil pressure? I havent had any problems yet just seems weird to have so much pressure.

Patman

But the problem with running a thicker oil just so you see higher oil pressure, is that this higher oil pressure is mainly because the oil is not flowing through the engine as quickly. So it gives you a false sense of security.

The key to choosing the right viscosity of oil is mainly in the type of oil temps you'll regularily see. Unless you're consistentely seeing oil temps of above 300F, there is simply no need for such a thick oil. And even then, you're better off solving that problem with an oil cooler, not a thicker oil.

If you truly want to know what viscosity works best for your engine, it will pay off in the long run for you to begin doing an oil analysis program. I highly recommend getting the Blackstone "Terry Dyson" service. This way you can correspond with Terry and he'll help you choose the right oil for your engine. He works with a lot of race teams, and is also a racer himself.