Looked for old posts on oil, but could not find one to match my question. Although new to Porsche, I am an old Harley rider and am aware of the needs of water cooled engines vs air cooled. My oil of choice over the last several years has been RevTech Pure 20w50 Motorcycle Oil. The Porsche owners manual recommends an oil with API Service SF or SE. RevTech has an API of SH/CG-4. I am very pleased with this oil, as I just came off an 8800 mile tour of hard riding on a rebuild with only 1.5-2 quarts usage over and above an oil change. I have heard of Porsche owners using Harley Davidson Oil. One point of difference among many between the Harley and Porsche is the use of roller bearings in the Harleys. Any thoughts on the use of this type of oil. My 82 911 sc Targa has 86,000 miles with an occasional puff when started cold and after long sits warm.

 

I met a rep from Mobil 1 at last year's PCA Parade. I asked what was the difference between 15W-50 Mobil 1, and the 20W-50 Mobil 1 sold for motorcycles. He said it basically the same stuff. The bike stuff is a bit thicker (not a bad thing with an old car like mine), but A LOT more expensive.
For an 911SC I am sure the 15W-50 stuff will work just fine.

 

Harley-Davidson motor oils are made for them by the Sun Oil Company. They are a good product, although I have used Mobil 1 in my '96 FLHR for 60K miles. I believe synthetic oils give a valuable safety margin to air/oil-cooled motors, against wear, and damage caused by excessive heat.

 

biker guy,

Agree with Dial, Mobil 1, 15-50. I have used this synthetic oil exclusively in my 911 for the last 8-9 years. The stories I have read from track guys concerning the tremendous protective qualities of Mobil 1 sold me forever.

Though I still elect to have the oil changed every 3,000 miles, my mechanic says with the Mobil 1, every 10,000 miles is fine, which certainly justifies the higher price of the oil.

Richard
'87 Carrera