Oil Pressure

[bmac]

Ok did manual gauge check on oil pressure.
20 PSI in Park @800 rpm NOT
15 PSI in Gear @650 rpm NOT

Seems to run 35-40 while driving.

Chilton's Manual says 60 PSI @ 1850 rpm

What do you guys think? Meets the general average
of 10 PSI per 1000 rpm that I've heard.

Do I have anything to worry about?

[MattStrike]

Looks OK to me. How many miles are on it?

[bmac]

115,000 Miles, Currently on the dealership oil change that I purchased it from.

I will be giving it an oil and filter change pretty soon. Any thoughts on 30 weight vs 40 for a
2002 SSEI with that many miles on it. I normally run 5W-30 Mobile One in most my cars.
Was considering looking at 5W-40 for this one.
I know that the OEM is 5W-30 but I've had some Old timer mechanics tell me you should
switch to 40 weight when you get high mileage on a vehicle.

[MattStrike]

There are a few forums dedicated to oil and oil analysis and who makes the best oil, but easily obtainable are the Shell Rotella T oils and the mobile 1 full synthetic oils. Going to a 5/10/15W-40 isn't going to hurt anything, but I can speak from experience that if you think you have enough bearing wear to cause low oil pressure to justify bumping up to the next oil weight - it won't help anything.

My cars all run with either Rotella T, valvoline maxlife, or Mobile 1, depending on what's on sale at the time.

[CMNTMXR57]

1) GM tells you what to put in based on certain driving conditions. Don't try to out think them. Sites like Bobistheoilguy can help but at the end of the day take things with a grain of salt because again, people on there ARE NOT engineers who designed and built the engine, lubrication system and everything else that is in your vehicle. GM did. GM cheapens out on a lot of things, but their oiling systems typically aren't one of them.

2) If you believe you have a lower than normal oil pressure, adding a thicker viscosity isn't a permanent fix. There may be something starting to (or already have) gone wrong and no oil is going to fix it. Going to a 40 over a 30, isn't a large change, so you will have minimal net gain to be quite honest.

3) Whatever viscosity oil you decide, make sure it meets GM standards, those being GM4718 or GM6094 (as those are applicable to your year), or even the current Dexos standard. We can have a pissing contest here over which oil is the best in the world, I don't care. As long as you change it at regular intervals with a decent oil filter (regular old AC Delco PF47), to me is more important than putting in the best oil on the planet. As long as it meets those previously mentioned standards and meets your budget, that's all that matters. Doesn't matter if it's a $4 quart of oil or a $40 quart of oil, as long as it meets those GM standards, you're fine.

[MattStrike]

For reference, the aforementioned list of oils approved to the GM standard:
http://stuartschmitt.com/car/gm_approve ... e_oils.pdf

My point is, if I know that oil "x" and oil "y" meet a certain standard, but oil "x" has better shear stability than oil "y", why would I buy oil "y" if they are the same price?

[bmac]

I agree on the pissing contest of oils and wasn't trying to start a contest. Lol

Was more interested in the other thoughts of oil weight for older engines. I ran
Mobile one 5W-30 in my wife's Tahoe was still going strong with 220K + when she
traded it. I just wanted a few other opinions.

Thanks for the replies and only time will tell on the wear.

[CMNTMXR57]

M1 5W-30 will work just fine. As will any conventional 5W-30. As long as they meet 4718, 6094 or Dexos standards per GM.

Matt,
when you refer to one property oil brand x may have over y, you're talking at maximum limits, which no one here will ever push their oil to, much less past.