On 8/26/2011 10:11 PM, Ed Pawlowski wrote:

"Erik" wrote in message
...

The big killer is combustion byproducts. Since engines are a lot cleaner
burning than they once were, this is reduced somewhat. The manuals on
my cars
recommend 7500mi for light service and 3000mi for severe duty. Look
up the
meaning of "severe duty" and it includes pretty much everything except
non-stop interstate driving in 70F, dry, weather.

This is true! Or 'light service' could be described as 7,500 miles, all
run in one 'trip', on a dyno, mounted in a clean room. Not 'real world
usage...

Rant mode on:

Rant all you want, but the truth does not bear you out. Yes, some people
should change at 3000 miles, but most would be wasting their money. Some
others should change at 5000 miles. I know of plenty of cars in the
100,000 to 200,000 mile range with no engine problems at higher
intervals. The people that warranty my engine for 100,000 miles would
not tell me to change at 75000 miles if it was going to cost them money.

Sorry, you were right 40 years ago, but not in 2011.

Nothing has changed. And i'd like to see the engine builder that
recommends the 75,000 mile oil changes.

--
Steve Barker
remove the "not" from my address to email