Ok, I have a friend who owns a 2003 Chevy Malibu. She is currently getting oil changes every 3 months and using only synthetic oil. If she needs to, how far can she space out those oil changes (I guess in terms of miles driven), and can she top it off with regular if she needs to, or does she need to stick with synthetic at all times?
I use synthetic in one of my cars, and I use a 7500 mile oil change interval. I am comfortable with that interval. So far, my regimen seems to work well.
Others run much longer, but I can’t bring myself to do it. I can say that the three month interval sounds way too short unless she puts a lot of miles on her car.
You can top off with whatever you want, but I keep a quart of the same type of oil in my car for top offs. I have always tried to keep the oil the same in the crankcase.
See the “synthetic oil change” thread below here for a few more opinions.
The owners manual for the vehicle will reflect what the manufacturer recommends for oil change intervals. And you will notice, nowhere in the manual is there a distiction between synthetic oil and regular oil and the oil change interval. The manual may only recommend to use a synthetic oil in extreme cold conditions.
Yes. You can add regular oil to the synthetic oil if required as they will mix. Ever hear of semi-synthetic oil? That’s a blend of regular oil and synthetic oil.
IMO that is way too frequent unless she puts on 7500 miles in 3 months. I would (and do) use regular old mineral oil and change at the frequency called for in the owner’s manual. Remember to factor in whether her use of the car is severe or not. Her frequent oil changes fave to cost at least $200 per year. If she drives 15,000 miles per year, she could pay less than $80 per year changing oil at 7500 miles.
She is probably wasting money by changing oil every 3 months unless drives about 30,000 miles a year at least and lives in a very cold part of the country.
If she drives and average of 15,000 miles a year, she should probaly have no more than 3 oil changes and if she lives in a moderate climate, any good “dino” oil will do.
My dealer charges $36 for a dino oil and filter change with an inspection, compared to $76 for synthetic. That’s $40 extra, and $160 per year. If she cuts back to 3 oil changes, she’ll save another $76, for a total of $236 per year.
The figures would be lower if done at a good independent garage. However, over a 15 year period that amounts to $3540!!! All that for allowing the engine to reach 400,000 miles instead of 350,000 miles!
The oil change interval depends on the type of driving. For normal mixed city & freeway, I would change oil and filter very 5000 miles, and only use synthetic if I lived in the Northern states or pulled a heavy trailer. If she is in sales and drives all the time the 7500 interval is suitable.