‘Is it OK to switch back and forth between conventional and synthetic oil?’
The Car Doc weighs in.
Boston.com Cars is your go-to resource for coverage of local car news, events, and reviews. In the market for a car or truck? Check out our new car specials and used car specials curated by our local dealer network.Q:
I’m looking for your opinion. For the first 40,000 miles, I used regular oil in my 2002 Ford Focus. The next 90,000 miles, I used synthetic. The next 50,000 miles I have switched back to regular oil. The car now burns a quart about every 500 to 600 miles. Could I have done any harm with the switching of oils?
A: It is perfectly acceptable to switch back and forth between conventional and synthetic oil. At 180,000 miles and 15 years old, the engine may just be starting to wear out. You can do some testing to see why the engine is using oil, although at this point it may just be cheaper to add one quart of oil once or twice per month as needed.
John Paul, AAA Northeast’s Car Doctor, answers questions from drivers every week. He has 40+ years of experience in the automotive business and is an ASE certified master technician.
