0w30 vs 5w20

greasemonkeyok · Aug 20, 2012

Z71 said:
but for how long will it stay a 50, not long at all.....

That depends on what the horizontal "cycles" measurement represents. The advertisement is meaningless unless that variable is defined.

DarkBlack · Aug 20, 2012

Z71 said:
but for how long will it stay a 50, not long at all.....

What the **** is that ??

No real meaningful testing lab would ever make a fat lined graph like that. And why is one company listed in bold and not the others.

B.S. ALERT!

I'm not sure now if it's just the comical amsoil salesmen littering the net now...

PoorMansCat · Aug 20, 2012

DarkBlack said:
What the **** is that ??

No real meaningful testing lab would ever make a fat lined graph like that. And why is one company listed in bold and not the others.

B.S. ALERT!

I'm not sure now if it's just the comical amsoil salesmen littering the net now...

yeah.. that one is shady looking..

greasemonkeyok · Aug 21, 2012

At least the Y axis has empirical numbers, but the X axis is pure BS.

If "cycles" = years, I'll stick with Polaris oil.

DarkBlack · Aug 24, 2012

It's a funny thing. I actually feel myself becoming ever more determined to never buy an amsoil product with every passing poser post I read. It's probably the exact opposite of what the amsoil salespeople are trying to accomplish.

WilliamBos · Aug 24, 2012

DarkBlack said:
It's a funny thing. I actually feel myself becoming ever more determined to never buy an amsoil product with every passing poser post I read. It's probably the exact opposite of what the amsoil salespeople are trying to accomplish.

I hate having to chase salesmen, and willnot drive to get it. Costcosells Castrolsyn now, will buy it there.

andres14725 · Aug 25, 2012

LD1 said:
So, all that said, it is really just a matter of 20w vs 30w oil that is the issue.

By adding a "W" behind the viscosity grade, it makes it a "winter" grade oil. SAE 20 is a different oil from SAE 20W. SAE 20W would be a "winter" grade oil, SAE 20 would be a "summer" grade oil. SAE20W50 would be a multi-grade oil meeting the "winter" grade specification for SAE 20W and the "summer" grade specification for SAE 50. "Winter" grade specifications are typically stated at temperatures below 30degF, "summer" grade specifications at 210degF.

Not to confuse issues further, but the lower viscosity grade is actually the grade of the base stock, so that SAE 5W20 and SAE 5W30 would be from the same base stock and have the same "winter" grade viscosity. SAE 5W30 would have additional viscosity improvers added to meet SAE 30 "summer" grade specification. SAE 0W20 and SAE 5W20 would be two different base stocks. Hope this simplified explanation helps.

Also, I haven't heard of engine failures using 5W20 or 0W20 in gasoline engines, but in our fleet of Hondas I use 5W30 just to help me sleep better at night, even though 5W20 is recommended. I don't trust the HTHS characteristics of the 5W20 to be sufficient, especially since I intend keeping these vehicles well beyond 100,000 miles. Thus far we have 220,000 miles combined on five vehicles (one at 83,000 miles) with no problems. But to each his own.

kbowley · Aug 30, 2012

greasemonkeyok said:
The first number is the weight of the Base Oil. So in a 15w50 oil, the base oil is 15w. Then they add thickeners that when the oil heats up, it has the same properties as a 50w oil. The bigger the spread in the numbers, the more the oil relies on the thickeners to perform at a 50w level. In other words, a 0w40 oil relies more on thickeners that a 10w30.

If you are in a really hot area where there is no benefit to the lower first number, my vote would be to use the higher first number.

This is correct with dino oils only. Synthetic oils use a base equivalent to the 100c rating yet flow as well as the low number when cold. For example, a 10w30 synthetic is a base 30 oil that flows as well as a dino 10w when cold. Full synthetics do not use viscosity index improver's because they are already a 30w base. This also prevents the oil from shearing down to a 20w as the vi improver's break down thus allowing for much longer change out intervals.

LD1 · Aug 30, 2012

kbowley said:
This is correct with dino oils only. Synthetic oils use a base equivalent to the 100c rating yet flow as well as the low number when cold. For example, a 10w30 synthetic is a base 30 oil that flows as well as a dino 10w when cold. Full synthetics do not use viscosity index improver's because they are already a 30w base. This also prevents the oil from shearing down to a 20w as the vi improver's break down thus allowing for much longer change out intervals.

I mentioned that once already back @ post #49:thumbsup:

MasseyWV · Aug 30, 2012

Regardless of oil weights (viscosity), it's worth mentioning that some premature engine failures (especially in older engines) have been attributed to reduced levels of Zinc, Phosphorus, and ZDDP (Zinc dialyldithiophosphate) in modern oils. All thanks to the EPA.

The main use of ZDDP is in anti-wear additives to lubricants such as greases, gear oils, and motor oils, which often contain less than 1% of this additive. It has been reported that zinc and phosphorus emissions may damage catalytic converters and standard formulations of lubricating oils for gasoline engines now have reduced amounts of the additive, though diesel engine oils remain at higher levels.[3] Crankcase oils with reduced ZDDP have been cited as causing damage to, or failure of, classic/collector car flat tappet camshafts and lifters which undergo very high boundary layer pressures and/or shear forces at their contact faces, and in other regions such as big-end/main bearings, and piston rings and pins. Roller camshafts are more commonly used to reduce camshaft lobe friction in modern engines. There are additives, such as STP(R) Oil Treatment, and some racing oils such as Valvoline VR-1,[4] are available in the retail market with the necessary amount of ZDDP for engines using increased valve spring pressures. See "external links" in this article. The same ZDDP compounds serve also as corrosion inhibitors and antioxidants.