Re: Synthetic oil vs. non synthetic oil

Posted by Tim Cole On 2011/12/28 19:28:01

Hi folks:

Since I deal with computer controlled automobiles I figured I would put in my two cents on this.

a) Mobil 1 extended service intervals are contingent on the use of the Mobil 1 extended interval oil filter. However, Mobil 1 is not recommended as a substitute for oil changes with guaratees for 15,000 miles or annual oil changes whichever comes first.

b) Synthetics are great for very high temperatures and extreme low temperatures. They are really good in air cooled motors for this reason. Lawnmowers and motorcycles love Mobil 1.

c) Today's computer controlled engines run almost infinitely cleaner than dirty old carburetors, suction tube crankcase ventilation, and perfunctory air filters so the detergency in the oil lasts longer in modern motors.

d) By the mid-1960's GM was extending service intervals to 6000 to 7500 miles which remains the standard for most motors.

e) Consumer Reports famous New York Taxicab study found that oil changes more frequent than 6000-7500 miles were a waste of money in modern cars regardless of so called "severe service".

f) For a clean occasional use Packard motor using detergent oil annual changes is probably adequate, although in worn motors with lots of blow by the use of non-detergent oil will keep water accumulations separate and therefore less harmful. However, for any Packard motor 3000 miles is probably the limit for detergent oil after which significant sludging will begin. I wouldn't go more than 2000 given how expensive these motors are.

g) I have been told that synthetics seem better for motors that sit because they are more tenacious and less hygroscopic, but I have never examined this myself.

Hope this helps