[joeclarke]

In contrast my experience with Mobile 1 is the opposite (of 1982911sc's).

Twice I have had wrenches put synthetic in non-leaking 3.2 engines (80k and 120k) and have seen immediate (couple of months) case leaks develop.

I have been closely associated with the refining industry for a few years and have seen lots of technical stuff on syn oil vs. dino. The most impressive of these is a video on lubrication in the valve train of a V8 when cranked in sub-zero temp. You'd use nothing but syn and/or always plug-in your block heater if you saw how long it takes dino oil to flow to the top of an engine at those temps.

But ignoring sub-zero conditions; with frequent oil changes dino oil gets the nod over synthetic for me. Cheaper, technically equivalent in the 99th percentile and wont turn my engine into a sieve.

Like the man said -

"Although, most of this may be psycological the car seemed to run better, more responsive, and smoother..."

I find the same when I move from 20W-50 in the summer to 15w-40 in the fall. Or even when I give the car a good washing/waxing - then it seems to really rip up the asphalt. Investments of money and/or sweat always make a car run at least one notch better...