Guys,
some time ago I wrote a treatise on oil pressure/temperature/engine speed.
It illustrated, clearly, that in as little as 2000 miles the pressure for
any given temperature would reduce by as much as 10 psi.
This oil thread seems to correlate with my theory, presuming that reduced
viscosity creates reduced pressure at the gauge. So, starting with 10w40
would be no different than running "old" 20w50 - at least in pressure
readings. Consider that startup pressure lag is the most destructive
element to our engines, a 5w50 synthetic (or even 0w30 if you can get it
South of 49) would be ideal - easy starting and "proper" viscosity.
Finally, here's info from the GT6+ manual I received with Silver:
Air temp 30 to 80 f: Duckham's Q20/50, Esso Extra 10w30, Havoline 20w40,
Shell Super 100.
Below 30 Everyone defaults to 10/30.
I presume 5w30 did not exist "back then" and would be yet a better choice.
My Honda Civic recommends 5/30 "for emissions and fuel efficiency" at all
times but 10 30 in the summer temps is also noted.
Plus ca change...
Dave Terrick
Winterp.... no Winnipeg, it is 35 deg. here
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