T- Berry's Mobile Auto Repairs



Vehicle makers have published two oil (and/or filter) change intervals for years. One -often labeled for so-called 'normal' service, makes it look like a driver can buy a car or truck and virtually forget about maintaining it. (Which most do!) The other schedule-for 'severe duty'-applies to many car owners who think their driving is 'normal' when it actually may not be. This double standard has led to no end of confusion.

The problem is the definition of 'normal.' The legendary 'Little old lady from Pasadena who only drove two blocks to church on Sunday's probably thought she was being easy on her car. That's the impression the dealer selling it was trying to convey.

Actually if she owned a '97 Eagle Talon, if each block were one-eighth mile, and she went by the book, she'd need to schedule an oil change no less than every 13 miles! (1/2 mile round trip, 26 weeks)

I'm not knocking the Talon; its recommendations are typical of most manufacturers. Lets check the book: Under' normal' conditions, a Talon's naturally-aspirated engine's oil should be changed every six months or 7,500 miles (whichever is sooner) with a new filter every other time. The turbocharged version calls for fresh oil every six months or 5,000 miles. Again, a new filter is required every other oil change. Intervals tighten up as the conditions change. Non-turbos need a filter at each oil change if they travel less than 7,500 miles a year. Under 'severe' service, both engines drop to three months or 3,000 miles. Again a filter change is called for at every other oil change (unless, presumably, the car is a non-turbo and it goes less than 7,500 miles/year, in which case it always gets a new filter! Following all this?)

The million-dollar question: 'What's severe service?' The Eagle manual provides several answers. In the case of oil and filter changes, service can be considered 'severe' if any of the following conditions exists:

Operation in dusty conditions

Trailer towing

Police, taxi or commercial use

Extensive idling, stop-and-go driving

Short trips at freezing temperatures

More than 50% heavy traffic or sustained high speeds at temperatures above 90 degrees

(Note that the Talon's service manual does not list repeated short trips as severe service, though some manuals do. If it did-assuming her engine were naturally aspirated, the little old lady would have to change her oil and filter every six-and-a-half miles!)

I don't know about you but that pretty much describes everyone of my customers and all of my friends. As a general rule of thumb, change your oil and filter every three months or 3,000 miles, Unless you drive a minimum of 80 miles @ 60-70 MPH a day, which is considered "normal driving". The higher RPM' s and extended duration at normal operating temperature (190-220 degrees) keeps the oil and engine cleaner because the heat burns off the sludge and crud that is normally produced.




67000 miles all in-town driving



Oil filter: Protects engine by holding and trapping contaminates. From both internal and external sources Change with every oil change

Air filter: Assures clean airflow into engine. Change every 10,000 miles and with every Tune-up

Fuel filter: Removes contaminates from the tank and engine compartment Change every 10,000 miles and with every Tune-up. Tank filter Not normally serviced

Transmission: Keeps fluid clean. Fluid and filter should be changed every 12,000 miles

PCV Valve: Keeps the engine from building up to much pressure And blowing out gaskets. Replace every 10,000 miles and check every oil change


Freon changeover

Why did I fail my emission test

Wiring Diagrams

TSB's and Recalls


Oxygen Sensors


Timing Belts_ 1970-1997 Domestic & Imported Cars

Brake Squeals



Last Updated on 01/21/2009
by Scott Throneberry