oil change interval?

[sixleggedinsect]

i used to religiously change the oil in my last escort every 3000. this time around i have an escort which actually has the user manual, and it says to change oil every 5000 miles for my kind of driving.

should i drop back to 5000? is this fine?

[AzTumbleweed]

I think 5,000 is about right. My manual says every 7,500. I really think the 3,000 mile oil change is something the 'quick-e-lube' places have got us to believe.

With diesel engines a lot of people (including the US Army) use oil analysis. You send a monthly sample to a lab and they tell you when to change your oil. It has saved millions of dollars. Truckers are doing this too so they don't have to change the oil so often.

[sixleggedinsect]

Originally Posted by AzTumbleweed

I think 5,000 is about right. My manual says every 7,500. I really think the 3,000 mile oil change is something the 'quick-e-lube' places have got us to believe.

With diesel engines a lot of people (including the US Army) use oil analysis. You send a monthly sample to a lab and they tell you when to change your oil. It has saved millions of dollars. Truckers are doing this too so they don't have to change the oil so often.

interesting. i had never questioned it with the last car- every time i changed the oil, it would come out dark and used and i figured that was sure evidence that it was time.

does that mean that dark oil does not necessarily mean its time to switch out the fluids?

[AzTumbleweed]

I think the dark oil means it's dirty. But that doesn't mean the oil is no longer any good. In diesel engines it gets like that immediately. Another thing interesting about the Army program is they can predict engine failure before it happens because of the different types of metal they find. They can also detect silicate (sand) indicating a bad air filter seal. It's a pretty neat system. Read more at:

http://www.almc.army.mil/ALOG/issues/SepOct00/MS534.htm