I got my SS/TC not to long ago and I'm still learning the ropes about everything auto so excuse the possible stupid question.

This car has had Mobil 1 fully synthetic oil for the past 20K miles, just a few days ago I decided to go with GM's cheaper alternative, AcDelcos very own Dexos brand of fully synthetic. My local shop did the oil change for me since I have no where to dispose of oil, I've known them for quick some time.

Anyway's the Mobil 1 oil ran at 45 psi on my oil pressure gauge inside the cab, and now i'm running at 60 psi. I can deal with a 5 psi jump, but 15? I don't know to much yet but I know that this is a pretty big jump. I'm about ready to go back and get another oil change back to Mobil 1 unless some one here can explain to me what the heck is going on. My local shop couldn't explain this so that's why I'm here.

Also my car isn't stock, has about 40hp worth of extra's on it and a trifecta tune.

 

What weight of oil were you using before and what now?

Also, in what conditions are you seeing the 15 psi jump, as in what RPM range and temperatures? Those factors greatly effect oil pressure results. It's perfectly normal for nice fresh oil to have better pressure than what came out.

 

I had Mobil 1 5W-30 and went to Dexos something I'll have to check when I get my receipt back at the end of the week but im guessing that was 5W-30 as well. Is that the weight your referring to?

As for the rpm and such, its just general cruising will say 45mph at 2K rpm in 4th gear. It use to bounce around at 45 psi and now it bounces around 60 psi.

 

You need to be sure that the cruising speed is identical, because a little more RPMs will increase oil pressure noticeably.

 

I notice as my oil gets old there is less oil pressure. usually around 50 psi, when oil is newer its 55-60. but 15 psi is a big jump. 45 psi is kinda low to begin with, so id say ur oil pressure is where it should be now

 

It seems to run fine. Did a few little "speed runs" and the car seems to be running just the same. I made sure the speed was the same around 45 mpg and all and that's what it is so I guess its all good then.

Just needed some reassurance, haha so thanks.

P.S. - Has anyone used either of those oils before?

 

I love mobil 1 full synthetic. How did you wire up an oil pressure sending unit anyways?

 

I run mobile 1 or penzzoil, both are good . Ur oil pressure for gauge all depends on where u have sender to. If ur in the head it will be lower than in block, if ur like me, I have a relocate kit with a 3 foot line running to a oil block where my sender is and a manual gauge for easy access. My gauge reads 5- 10 psi lower than it would directly in the block.