http://lubricants.s5.com/oil_pressure.htm

Good info--and I believe it--5w20 in mine since new, 47,000 miles ago.

Dan

 

I agree.Did you know it only takes 3-5 psi to run a small block chevy?..........

 

Interesting article. Think I am going to drain the 60w and switch to something lighter. So how come most racing motors are running 50w? And why does VW insist that I use 40w in my turbodiesel? 0nce I finish rebuilding my motor with the forged pistons I think I will switch from 5w30 to 5w40 and use the same oil in both vehicles.

 

Very basic fundamentals of oil. Doesn't really provide any in depth look at viscosities and their characteristics and it doesn't say what they consider to be to heavy of an oil.

 

I am running 0w-20 Mobil 1 in my motor.

 

That article is bunk. 0w40 M1 here. If you ever turn any revs, you want a thicker hot temperature oil.

 

I think that article is more about oil pressure than oil thickness, which are related but it looks like they were giving causes of high pressure(blocked oil galleys,etc) and lower oil pressure(free flowing oil) meaning the oil system is working properly.

 

Maybe factory eng. specs. as to clearances(cyl/piston, main bearings, etc.) where a 'thicker' oil is needed?

The specs. on our modular engs. are suppose(?) to be closer/tighter, calling for a lower weight/viscosity oil. I don't think it's just to meet CAFE mpg standards as some have said.

Dan

 

http://www.fammllc.com/htmlpub/LUBE_bulletin_06.htm

http://edmunds.nytimes.com/ownership...1/article.html

Dan

 

I know first hand that a 10W40 will spin a bearing in a mod motor. Spent a weekend at thunder hill in my brand new cobra in 1996.. Had a nasty knock from the motor come monday morning. Car had roughly 10,000 miles on it.

Took it into the dealer and they replaced the motor with a new one due to a spun rod bearing, #7 to be exact. They made it a point to tell me NOT to use anything heavier then 5W30. I went to 0W30 for safety.

Ive seen some guys adding 10 W to 5W, half and half mix for a 7W30 mix, kind of crazy if you ever see the oil galley's on these engines. 30WT is plenty for these suckers.

 

I think you missed my point. I was refeering to the article not addressing what they felt was to high of viscosity for oil and how it related to the modern engine. Is 30 weight to high? 40 weight to high? What type of engine were they refering to? Hopefully you can see that there were a lot of unanswered questions in your article and it would be impossible to base a viscosity choice off that article. I'm very well aware of the concepts of oil and viscosity, as I have been selling it for over 20 years.

 

I don't think anyone has ever had a problem with a car that has installed the oil weight the factory recommends.

If it spins a bearing because you put 5w20 in it, then you can come and preach the negatives of using such a light weight oil.

Just my $0.02

 

Have always used 5w30........no probs ever..............

 

Sorry, I did miss your point. Thanks for not 'nailing' me .

Dan

 

Which modular motor are you referring to. The factory specs called for using 5w30 oil in my '00 motor. For my '01 motor Ford changed the specs to 5w20. Did Ford all of a sudden start building our engines to different tolerances? I don't think so, I believe it was to help them meet the CAFE standard. I've continued to use the 5w30 in the newer motor and when it was torn down it looked brand new. But when the forged pistons go in I think the tolerances will be looser, which is why I am considering switching to the 5w40. Opinions?