[78w72]

Originally Posted by AG

There is no reason to run that heavy weight oil. Oil flow is more important than the higher oil pressure you get from heavier weights of oil and as long as you are getting 15-20 psi at idle with 10W-30, then you are fine. I run 10W-30 in my race car without issue.

x100... no reason at all to use 20/50 in any street engine. people still believe the myth that it "cushions" better or some other reason that thicker is better. these aren't top fuel dragster engines & nobody in the street section needs to run that thick of oil.

its not "wrong" to use 20/50 but the benefits of a thinner oil, especially in a street or street/strip engine, far outweight a thicker oil. try a 10/30 or maybe 10/40 if you think thicker is better & you will see your engine runs perfectly fine & no damage will be caused... the bearings & oil pump rod will be much happier too & you might even gain a few HP & MPG!

[Formulajones]

Again....depends on the oil. To just say 10-30 is going to flow better and...yada yada is a little vague. Need to be brand specific because like I said, there are 20-50's on the market that flow even better than some 10-30's.

It really depends on what you're using.

[Richie Hoffman]

I use ULX 110 from Australia

[Formulajones]

There's one I haven't heard of. LOL

Edit: Okay looked it up. That's Australian based and Australian made.

[78w72]

Originally Posted by Formulajones

Again....depends on the oil. To just say 10-30 is going to flow better and...yada yada is a little vague. Need to be brand specific because like I said, there are 20-50's on the market that flow even better than some 10-30's.

It really depends on what you're using.

its a general statement that covers the majority of normal off the shelf oils. yes there are "some" thicker oils that pour as good as other thinner weights, but based on that chart its almost only the high dollar oils like amsoil, redline, royal purple etc... the vast majority of 20/50 oils are no where near a 10/30's numbers.

also, pourability is only a measurement of a "chilled" oils ability to move freely. what matters more in the real world of an engine operated in normal warm climates is pumpability, the ability of the oil to flow through tight clearances & as others have said provide cooling to bearings. 9 out of 10 20/50 oils are not going to do that as well as a thinner 10/30 oil. you cant compare a high dollar synthetic oil to a standard conventional oil.

[Formulajones]

Originally Posted by 78w72

you cant compare a high dollar synthetic oil to a standard conventional oil.

Sure you can, when people are making a "blank" statement about viscosity and flow characteristics without the mention of what brand oil they are using, then it's an open playing field as far as I'm concerned

If you want to boast about how good your 10-30 is flowing, lets break it down by brand and additive packages. Because they all aren't the same. Lets inform everyone and be specific. That's what we are here for, to share good information.