Synthetic Oil Improvement in /6
When I put 5w30 synth oil in my bonestock 318, in favor of 10w30 oil... The engine ran 15f cooler after it.
Can you imagine how much friction has been freed up in an engine for it to run 15 degrees cooler?
I would not predict that but I can believe it. My engine experience with Mobil 1 used for a quarter million miles in each of several street engines and a dozen moderate HP race engines is that :
1) The ring, piston, and bore wear is dropped almsot to zero for a standard street car, and dropped a lot for a race engine
2) Bearing and journal wear is dramatically dropped for both street and race
3) Rocker wear is reduced but not nearly as much as for the rings and bores
4) Hydraulic lifter internal wear is not really changed much and they still lose their check valves over long periods of use
5) I have not measured cam wear but I have never lost one with it
6) Chain & chain gear wear seems to be almost none, but chain stretch does not change.
With #1 above, I would guess that's why your engine temps dropped: a lot low lower ring friction on the bores. It might also explain why I think I have noticed a perkier /6 operation with this change. And it certianly would explalin why you DON'T use Mobil 1 'til the rings are well seated!
