Motor Oil

Hello fellow 911s owners,

I recently completed a total rebuild of my engine and replaced the original 2.0 S heads, pistons and cylinders with 2.2 S parts. My mechanic who performed the rebuild is recommending that I use Mobil One from this point forward. I am curious to know if anyone out there has switched to a synthetic oil after performing a complete rebuild of their engine and whether this would be considered an unwise decision. I trust my mechanic, but I would really appreciate any advice or general comments regarding this issue.

Best Regards,

Austin

IMO stay with the dino stuff Kendal 20/50 is good

I don't know about the dino stuff. I rebuilt my 2.0 liter engine to 2.0S specs 1 1/2 years ago and after appr. 2,500 miles of break in miles made the switch to Synthetic (Mobile 1). Based on current technology and studies which support the fact that synthetic oil works better in keeping your engine cool as well as better protected, and only needs to be changed every 12-15k miles instead of every 2,500 miles, the only arguement to be made for staying with organic oil is upfront cost. 10 quarts of Mobile 1 ain't cheap....

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Originally Posted by gruen911

the only arguement to be made for staying with organic oil is cost. 10 quarts of Mobile 1 ain't cheap....

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You get away with 10 quarts? In Kermit, I put a whole case in -- Twelve quarts. I use Castrol GTX 20W-50. Costs me $2.10/qt. Don't know if my oil cooler is part of the reason, but I don't drain it when I change the oil. Still can't figure that out.

But I do know that with the cooler, even in 100 degree temps, running AutoX this weekend, and highway miles to get to the site, the temp never rose above 210. I guess that the extra moolah spent on the cooler was worth it.

larry

the mechanic who rebuilt my 2.7 filled it with castrol 20/50 upon start-up. he likes castrol and mentioned that i would see see slightly elevated temps with kendall.

my regular mechanic likes kendall...he likes synthetic redline even more and recommended that i run redline after 2500 miles.

it has also been mentioned to me that synthetics should be reserved for track cars.

i think the decision to go with synthetic is based on the quality of the rebuild and health of the engine.

everybody has their opinion and reasoning.

I would use synthetic on a fresh rebuild, after break in is complete. Every motor I have switched over from dino to synth feels appreciably smoother throughout the rev range. I would not switch on a higher mileage motor, though, due to leak potential from the well documented seal swell issue.

Kendall is great oil. I've used it in my racecars. With carbs (webers), the issue about changing oil has to do with the amount of raw fuel being dumped into the cylinders and then getting in and diluting the oil. But Mobil 1 is also wonderful. My fuel mileage increased a few percents in my M3 after switching, and my truck runs noticeably cooler. There were a lot of oil tests done on motorcycles, and there is definitely a HP difference (increase) with better oils.

I switched backed to dino oil because of leaks that I had with synthetic, there was a small 10degree rise in operating temp but I enjoy keeping my garage floor clean.

Thanks for all of the thoughful replies. Based on your feedback, I think I'll stick with the Mobile One from now on. I've put about 2,500 miles on the engine since the rebuild and the power difference is very noticable. I am a huge fan of the 2.2S conversion...especially when the motor is running at 5000 RPM and the stick is in fifth gear!!! :D

hope to see some of you guys on the road...

Austin,
If you like the feel of 5th 5,000 revs, wait until you get to 7,000, and bring a diaper!