Another reason for a "slightly" higher grade oil ?

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Dec 12, 2002
Nah, no 20W-60's, 70's or the like.

There was the study posted a while back on HTHS and the requirement to stay above 2.6.

We are all pretty confident (even us Aussies are starting to turn around on the issue) that a 30 weight will not destroy an engine (in spite of Shell XMO 15W-30 - must have been near 100 V.I being labelled as such 15 years ago).

I was looking in the diesel oil analysis section at the viscoscity drop apparently associated with around 5% fuel dilution.

The resultant viscoscity was within my manufacturer's range of acceptable, but most certainly would not have been if I'd started at 10cst.

Is potential fuel dilution a genuine reson for picking a slightly thicker oil ?

Sort of like an insurance policy for an undiagnosed injector problem ?

Originally posted by Shannow:

Is potential fuel dilution a genuine reson for picking a slightly thicker oil ?

If your asking if there is potential for some very poor used Hondas being available on the used car market in the future I'd have to say yes , the potential is certainly there .

Take a oil starting at 7.8 cSt and unknowingly run it to 7500 with 2.5 fuel a few times might weaken the motor right at the knees
Pretty much my point.

Used oil analyisis will tell you early that there's an issue, but blind faith in oil change intervals would make me err on the thick(ish) side.
Yeah, I've thought of that as well. A more interesting observation comes when fuel system cleaners are seems to dilute the oil depending on the strength of cleaner. May be a case for going up in viscosity...
It would certainly allow race engines to run thinner oils, as 500 miles may entail two or three cold starts, followed by 500 miles of high temperature boil-off.

Versus 20 cold starts, and rarely to temp for the rest of us (repeated 10 times on one oil change)
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