which 5w-30?

[kschachn]

Look at HTHS of a 5w30 vs a 0w30 from the same brand and why 0w oils lost BMW LL01/LL04 spec. They're not as robust.

That’s not the reason here. Look up the approval HT/HS requirements for this brand and you’ll see your statement isn’t correct.

That’s why approvals are so important. That’s what dictates the HT/HS and it’s not a different requirement for a different winter rating.

 

[svenson]

It helps to remember that grade is a recommendation not a spec. Engines are designed to tolerate a minimum HT/HS without excessive wear, an oil with a higher one is acceptable and often desirable.

we are talking about a minimum hths that engines tolerate. but how high hths can tolerate? always within approvals or more?
example..mine is from 3.5 hths ,0-30 to 4.0 hths a 5-40 redline e.x
can i go higher out of the approvals? can the engine tolerate higher hths? i know i wont do it,i know it has disadvantages, more drug,more fuel consumption etc. but can the engine tolerate a so higher? just wondered

 

[kschachn]

we are talking about a minimum hths that engines tolerate. but how high hths can tolerate? always within approvals or more?
example..mine is from 3.5 hths ,0-30 to 4.0 hths a 5-40 redline e.x
can i go higher out of the approvals? can the engine tolerate higher hths? i know i wont do it,i know it has disadvantages, more drug,more fuel consumption etc. but can the engine tolerate a so higher? just wondered

Is there an upper limit for any SAE grade? There are 70-grade oils used in Australia and there aren't warnings on the labels that the high HT/HS could damage some engines.

As long as the winter rating is appropriate for the starting temperatures, how would any grade damage the engine?