J.B.H.

105k and counting...still under the 1qt per 1000mi...would say 1/2 quart per 800mi...
Oil changes/Air Filter/Plugs do them more frequently and good luck!

Kika

+1,000,000,000,000!

^^^^
Great advice, apply to all posts

ca993twin

This is an old thread, but that won't stop me from commenting. I wanted to mention that engine longevity is also related to your driving style. If you do a lot of cold starts and short drives where the engine is rarely brought to full operating temperature, or you take little care with driving gently until the engine is fully warmed, or if you rarely take it near to the redline, your longevity will probably suffer.

race911

Oddly, not in my experience when I ran my shops. Figure my database at shop 1 was ~200 911s, maybe twice that air cooled when you figured in 914, 912/356. While fewer than 10% of anything over 20K miles was original owner, nothing I took apart (puked tensioners and pulled head studs, mainly) showed excess wear despite owner's best (worst?) efforts in the 50-150K mile range.

Moving to shop 2, when I was mainly picking all the 2.7 cores I could find to piece this and that together + doing the valve guides so that I had an affordable alternative to keep he 2.7 cars on the road, I usually never had to throw anything away but a crank that couldn't be reused as standard or high mileage Alusil barrels, unless the thing was run out of oil.

goofballdeluxe

Ken, I'm curious since our 993s hold, what, 12 quarts of oil, how many quarts low on oil would need to be missing before damage might occur? In other words, I know our cars would be fine running low on a quart or two, but when would damage start occurring? Running 5 quarts low? 8 quarts? 10?

Interested in your opinion since you've opened up so many air-cooled engines, and I always wondered with the threshold number is on a 3.6 that holds 12 quarts of oil...

Jim W

Just turned 116,000 miles with very little oil use and 'feels' strong.

race911

For just "going down the road" engines, I've added as many as 6 quarts and never dealt with the customer again on anything major. (Yes, I specifically remember since it was a woman owner who was referred to us, and uh........things kinda got personal with my partner and her for awhile.)

My belief, on the old 2.7s (and some 2.4s that ran hot in AZ) was that low oil pressure at 250F+ was more of a killer. Some of the things barely ran 15psi @ 3K under those conditions. By comparison, I think any of the aluminum engines (3.0-) are indestructible if you even pretend to regularly check the oil. (At least everything from an SC on had a minimum of a trombone cooler up front.) But that could be only 5-6K with one of them with bad guides, and burning a quart every 6-700 miles.

mongrelcat

Amazing. Thanks for sharing, Ken.

mdude

Are you saying taking the engine to redline from time to time is good for the car?

timothymoffat

My 95 is just over 18 years old and has about 83000 miles. No drips in the garage and doesn't burn oil as long as its exercised.

My 97 is almost 17 years old and has 86000ish miles. In the 5 years and15000 miles I've owned it, I've only had to add 2 litres of oil between the 4 oil changes I've done.

Vandit

In addition to oil consumption, an oil analysis will give you some insight into the health of your motor.

http://www.blackstone-labs.com/

berni29

Hi

I took my motor apart at 186k miles for a broken piston ring. The guides were shot, but the rest of the engine was in excellent condition. Before the rebuild although the guides were worn the car did not use much oil or smoke on start up. I think regular oil changes is the most important factor especially for cars used for frequent short journeys.

Berni