Originally Posted by Triple_Se7en
Originally Posted by dlundblad
Originally Posted by Triple_Se7en
Isn't the only decision - is to stay within the viscosity index inside your owners manual, during the warranty period?
Ah ha! I knew this was coming. To answer your question, yes.
What exactly do you mean by viscosity index? A list of suitable viscosities depending on what is available, driving conditions etc? This to me is a non issue since it gives you more than a single option.
Usually a chart exists in the owners manual, citing outdoor temperatures and attached viscosity numbers to go by. That's what I meant.
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A later post by another member states that engines can run on more than what the owners manual states. True and it works, unless an engine problem occurs during warranty and the owner gets caught / blamed for the problem that's associated with what was used, outside of viscosity numbers allowed for warranty coverage.
Different viscosities may be better. But I would not use them, until the warranty is expired. If you adopt Australia owner manual stipulations for driving in the USA, well, good luck getting automakers to side with you in a dispute. Better have a good lawyer, that's well versed in gasoline oils.
Yes if there's a chart, it's a non issue.
Say there's a truck with a big V8 that specifies 5w20, but a "2500/ super duty" with the same engine specifies 5w30, what would be your preferred choice? The engine can obviously use both.
I'd use the 5w30 personally.