I don't have the exact answer you're after, but to generalise I suppose it would be "longer and longer".

This, of course, is largely dependent on the car in question.

For ordinary family cars, the car manufacturers are trying to reduce the perceived cost of ownership with ever longer service intervals.

30k intervals? - not sure if they're there yet, but they're not far off...

Rich

 

Wasn't there a car on Top Gear about a year or so ago..... an Oldsmobile or something, that they reckoned had a 100,000 service interval and could run on NO oil in an emergency?

 

The manufacturers recomend 5,000km then 10,000 for the filter. Unless you own a Porsche.

http://www.fernblatt.com/longhurst/engineoil_bible.html

 

Depends on how hard on the car you are if like me you are hard i change mine every 2000 to 3000 miles cause it just gets so black filter evry 6000 complete flush evry 3rd or 4th oil change usually with filter change

 

if you run the same brand and grade of oil the whole time and that you constantly check the dip stick, you would have an ideq of its "behaviour" over time. For me, I have been running semi synthetic Mobil S 10w-40 for the longest time and I know (given my driving style, weather, etc) the oil is good for only 4000 kms before it starts to burn .. hence this is my oil and filter service interval. There is NO generalisation for this type of thing, the amount of wear and tear and driving styles are so different. What is a 10k service interval for your granny is perhaps a 3k for you.

 

I don't want to start The Great Oil Debate (tm) again, but just how long does oil last in usage before its key parameters (film strength, viscosity, shear strength etc) are completely gone?

For example, there's a well-known US brand called AMSOIL, which claims to enable "extended drain intervals" of over 20,000 miles without significant degradation. And now you can get these "long life" oils for the latest VW / Audis. My bro-in-law's TT has done 14,000 miles since the last change and the service indicator is still not showing a change is due.

Does anyone know where there's any data about just how long oil lasts in road driving (not racing) conditions?

[Edited by brickboy - 6/11/2002 5:16:21 PM]