Delo 15w 40 or a 10w 50

[Francis]

As some here will know and some will cringe at the thought. I like an oil the ends in 50. 20w 50's and especialy mineral ones have over the years proven to be a tuff old oil for the best style of engines. V8's! 60's to 80's style grunt machines is what I'm talking about. Both Flat Tappet and Roller styled.

Lately I have been looking at either using (trying) a 10w 50 (Penrite HPR10 or Valvoline Syn 10w 50) or a higher zinc style oil like Delo 15w 40 (mineral).

Of couse the oil is changed very often, so long drain is not at all an issue.

Any thoughts on which way to go?

 

[vronline]

The Delo or Rotella 15w40 would work well.

 

[aquariuscsm]

Anyone every try Royal Purple`s 15W40? Their oils seem to be really thick. Like Francis was saying,I bet thick oils like that are good for those beast V8s. Seems like a muscle car type-engine would really give an oil a hard workout!

 

[aquariuscsm]

Do those 15W40 diesel/gasoline rated oils contain more detergents,or is their something else in them as well? They always have both gas and diesel recommendations on the bottles I`ve noticed.

 

[Francis]

Quote:

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Do those 15W40 diesel/gasoline rated oils contain more detergents,or is their something else in them as well? They always have both gas and diesel recommendations on the bottles I`ve noticed.

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Yes normaly they have a bit more calcium.

 

[Francis]

Quote:

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Anyone every try Royal Purple`s 15W40? Their oils seem to be really thick. Like Francis was saying,I bet thick oils like that are good for those beast V8s. Seems like a muscle car type-engine would really give an oil a hard workout!

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Well you take in to account just how different these engines
are to a multi valve 4 cylinder styled engine.

First of all you have this huge valve spring that's pushing hard to keep the valve closed and hard down on the push rod lifter and super hard on lob of the cam.

Then you have this huge big crank that's trying to throw everything out of the engine sideways.

I have no doubt that in smaller little multi valve engines with #@$%! week valve spring pressure and little small cranks yes thinner oils are better, but with the "typical styled engine components that a classic V8 has, you have to look outside the "technical haze" and marketing hype and understand that they are very different engines with very different requirements.