OK Folks...
Here are my first impressions/-seat of my pants-observations on the Swepco (mostly)5W30. So far its been >500km and 10 days. The engine is running quieter at any cruising speed, all I hear is wind/road noise. Start up is quick and the rough idle is gone. Fuel consumption seems to be a tad better (gas gauge), I will have hard numbers after a few fill-ups.
As for the piston slap.....
It has changed......
It is now clear, clean, crisp, somewhat like well tune castanets....I've never heard so well...
Obervation #2
Started the van yesterday AM, temp was 8*C, initially was quite for the first 5+ seconds, then the piston slap begins, and is present at almost every start-up during the day. Compared to M1 the piston slap starts, then disipates fairly quickly and does not return until the next mornings cold start. - Advantage M1
I am inclined to believe that this oil has good merit, but not for the GM3.4L. Maybe for the Acura.
As some members here have said "some oils are better suited for particular engines.."
Any comment welcome..
Stay tuned for more info.
Jean