Oil Weight Question?

[DRTYFN]

Learn to use the SEARCH feature. And pay attention to F5's advice.
http://www.elcovaforums.com/forums/s...ight=oil+5w-30

[stagger_lee]

Originally Posted by DRTYFN

Learn to use the SEARCH feature. And pay attention to F5's advice.
http://www.elcovaforums.com/forums/s...ight=oil+5w-30

Yeah I did SEARCH and read all that, I understand differences between Synthetic and Non, but question was directed to weight, those differences, pros and cons of heavier weight oil, were not explained. Just curious.

Graydouche

[Desert Dan]

Most new engines are using lower viscosity multi weight oils like 5-30wt.

I am not sure why? That would be an F5 question
Maybe higher tolerances require thinner oils or the 5-30wt lubricates better?

What about in extreame heat 110 degrees plus is the 5-30 good enough?

[stagger_lee]

My exact questions, when to use heavier weight and why?

[graydog]

Originally Posted by fagger_lee

My exact questions, when to use heavier weight and why?

ITS over your head dude just drop it.

[Vettster]

Originally Posted by Desert Dan

Most new engines are using lower viscosity multi weight oils like 5-30wt.

I am not sure why? That would be an F5 question
Maybe higher tolerances require thinner oils or the 5-30wt lubricates better?

What about in extreame heat 110 degrees plus is the 5-30 good enough?

Part of the reason is for fuel savings.
Living where I do, I always use heavier oil.
Mobil 1, 15-40 or so.

[f5fstop]

The 5W is used for energy conservation during cold engine operation. A lower weight also allows for oil to flow up to the top of the engine more efficiently in cold weather. The 30W is the maximum GM recommends for any gas engine they now manufacture (the Honda engine in the VUE required 5w20).
These requirements are per SAE, and it means in cold temps, the oil will flow like a 5W, as the engine warms up it will flow like a 30W. Some type of index viscosity additive is used to make this all happen.

Using 40W in ANY modern GM engine will most likely cut its life span. In addition, I don't believe any 40W or greater oil passes GM's required spec for the H3 engine. If you ever have a major internal engine problem, and a GM field rep gets curious, he/she may send a sample out for testing. In two days, they can tell what oil is in the engine.

What oil you should use will be debated until the end of time, just like when to change your oil and which is better Chevy or Ford trucks. So, I'm just telling you what GM requires, that is in writing in the owner's manual, and to understand, using this recommended oil WILL not cause engine problems. I always have used 5W-30 in my Vettes and lived in the south, and had no problems.

[stagger_lee]

That makes sense. Good thing I obeyed the requirements. So would you say that a heavier weight would work better in hotter running engines, ie: aircooled VWs and porsches, diesels, hot rods running high compression and forced induction, etc.?

Thanks for the info F5.

[deserth3]

No. It has to do with engine tolerances. In older engines when they start to burn excessive amaounts of oil people would put in a heavier weight to put off rebuilding the engine.
The heavier oil would not pass between the cylinder walls and rings.