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Old 10-28-2015, 04:36 PM
v8volvo v8volvo is offline
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Location: Montana, USA
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Quote:
Originally Posted by Goteborg Vapenfabrik View Post
Fully synthetic oil is a big temperature reducing factor.
To my knowledge, it's not so much that synth reduces temps (though it may do that to some small degree), but rather that it stands up to high temps better - doesn't break down like conventional oil does, and much less tendency to sludge, coke, deposit buildup, etc. It seems to be true that for moderate driving, on flat terrain and in moderate temperatures, you can do away with the cooler and not suffer any functional repercussions to speak of.

But for serious driving under load in warm conditions, with the oil in a D24T absorbing heat from the turbo and piston-cooling spray, I think you definitely still want a cooler of some kind in the circuit. Synthetic or not, the oil plays a role in keeping the engine cool, and while synth can get hotter without having problems of its own, the components it's designed to cool still need it to stay at a temperature that makes the cooling effective. (And even synthetic oil has a temperature danger zone that you'll want to stay out of.) Tom Bryant also says that D24T engines have no cooling problems, which is presumably the truth in his particular usage conditions, but those of us who do serious mountain driving in the western states and subject the motor to sustained loads at high ambient temps know that keeping these engines cool when they're really working hard is a challenge not to be underestimated. Assess the oil-cooler debate from the same logic; YMMV depending on what your situation and intended use is.
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