Then you should know that sometimes you should run 20wt, especially if your engines oil 'arteries' are clogged or getting clogged...

 

Right! Dr haas just says it in a scientific manner. Were just breakin it down into lehman terms.

 

yeah thats why the advice shouldn't be "dont use 20wt" it should be read this article, then experiment with different wt oils

 

As an example: I read the article and switched from 10W-30 to 0W-30 and my pressure is too still too high. I'll be seafoaming my car to try to get my oil passages cleaner, then running 5W-20. Later if my oil pressure is too low for dd I'll switch to a heavier oil..

 

pressure still too high when? what do you consider way too High???? Unless we're talking about 80+lbs on a stock motor at idle or something you're overeacting. Have you verified these "HIGH" pressures with an accurate mechanical oil pressure gauge?

If you've got clogged oil passages you've got other things to worry about than motor oil choice. Given clearances for a stock motor, I personally wouldn't run a 5w20 unless it had really low miles.

 

You read the article, yet expected your pressure to drop when switching from a 10W-30 to a 0W-30? Unless you're referring to cold start pressure, you may have not understood what you read, or the author did a poor job of conveying accurate information.

 

^exactly, good call! I agree with buffman too... Mr. camaro you over analyzing this oil thing, Just keep 10w30 in and drive it.

 

Yeah I'm resurrecting this thread been busy with school so I havent been on ...

I never said way too high but it is higher than the goal of approximitely 10psi per 1,000 rpm. My pressure also peaks too low, at about 2,000 rpm (around 45psi)

Everybody with an old engine has some kind of clogging/deposits in the oil passageways, this can be especially true if you aren't the first owner and can't be sure that it's been taken care of.

A few excerpts from the article:

"I truly believe that oil is much better being too thin than too thick. Over the years we have been going to thinner and thinner oils despite hotter engines with turbos and the like. The tendency is that people figure they need a 40 weight oils but then use a 50 instead. Better thinking is that if you think you need a 40, use a 30 weight oil instead. I firmly believe this based on all I know about oils.

The best way to figure out what viscosity of oil you need is to drive the car in the conditions you will use. Then use the oil viscosity that gives you 10 PSI per 1,000 RPM under those circumstances. For some reason very few people are able to get this simple principal correct. I cannot explain further.

These same rules apply to engines of any age, loose or tight. Just because your engine is old does not mean it needs a thicker oil. It will need a thicker oil only if it is overly worn, whether new or old. Yet the same principals of 10 PSI per 1,000 RPM still apply. In all cases you need to try different weight oils and see what happens. Then choose the correct viscosity.

Some people have tried this and occasionally get a somewhat low oil pressure while at idle. This is fine. There is no stress on parts at idle, the smallest oil flow will do the trick. It is at higher RPM where more BHP is produced. This is where we need the flow. Remember that Ferrari uses 75 PSI at 6,000 RPM as the place to test your oil viscosity needs. If your oil gives this value under your driving conditions then your lubrication system has been maximized. Period.

Older engines may in fact benefit from thinner oil use. Over time permanent deposits of carbon and sludge build up in the engine oil ways. It is like a clogging of arteries in humans. We are now all on blood thinners. This is an area I specifically studied while a general surgeon resident at Chapel Hill.

For those engines with excessive varnish and carbon buildup the engine oil additives of the detergent type may be of benefit. On the other hand you could just use a thin synthetic oil and change it every 200 miles for a while and end up with an even cleaner engine. With everything working properly you may actually need a thicker oil if that engine is overly worn. The thicker oil would be a disaster however, if the arteries were narrowed from deposits.


The Test: Get your car up to normal operating temperatures and test if you can get close to having 10psi per 1000 rpm."

 

No I read the article and began experimenting. Plus I couldn't find a jug of Mobil 1 5W-20 at the time and I couldn't pass up the deal on Mobil 0W-30 at WalMart ($23 for a 5qt jug of full synthetic )

 

Then there was absolutely no point in making the post stating your oil pressure not changing when going from 10w30 to 0w30. RIGHT after you said you read the article. All it did was make the article out to be crap and/or you to be a tool lol

 

Wow lol!

 

again I still think you're overreading what he's having to say. 10psi per 1000rpms is min as stated in most books. You can have more pressure than that. Too much pressure is a bad thing also (wastes HP), but IIRC the F-cars got the higher pressure spring in the oil pump compared to us b-car guys.

 

All I know is, when I'm making over 3K RPM, I'm too busy looking at the road instead of my oil pressure to make sure I'm meeting that 10psi-1K RPM

 

I don't think I ever seen a gm motor operate that way. Usually when a motor climbs up to 2k+ you see the oil psi gauge increase to whatever and stay there, not increase on a 10psi to every 1k rpm ratio.

 

The point I was making was that I was going to experiment with 5W-20, if you read my later post I said I couldn't find a 5qt jug of 5W-20 at the time. I also knew I was going to take off my oil filter/do an oil change when I install my LPP LT headers so I just grabbed 0W-30. I mispoke it happens, I'm not going to double check everything I write on a forum.

 

Yeah its a goal, not necessarily achievable on all engines. Your supposed to experiment and get close to that. Plus I said my pressure was peaking at about 2000 rpm, its definitely not supposed to peak that low... atleast not from what I understand.

 

jeez guys i already went out and bought some 10w-30 a week ago jeez haha. never meant for this to turn into a 3 page thread haha

 

Unless you were referring to cold start pressure, why would you state that when you switched from 10W-30 to 0W-30 your pressure was still too high unless you were expecting a drop in pressure? At operating temps, both of those oils should display the characteristics of a 30 weight oil.

 

MR camaro have you actually verified these temps with a mechanical gauge after the car is fully up to temps (oil temps in the 180+ degree range)

 

Ya, I read that later post, but it's a moot point in this case. If you're not going to double check everything you say, then don't get mad when people think you've lost your marbles and don't know what you're talking about.