Car Talk Spilling the tea on an irreproducible experiment
DEAR CAR TALK:
I bought my Toyota iM in February 2017 as a second car to our family RAV4. As of this morning, it has only 10,800 miles on it, with an average speed over that time of about 30 mph.
Essentially, I drive it to Kroger’s (one stoplight), CVS (two stoplights) and the golf course (5 miles on the highway).
At my dealer’s suggestion, I have them change the oil every six months, which means I average about 1,600 miles between oil changes. Under my circumstances, should I really change the oil every six months? Or should I do it every 5,000 miles?
The dealer says that in six months the oil gets stale, i.e. some moisture gets in there, blah, blah, blah. Is he spot on, or is he just blah, blah, blahing me? Thanks.
— Terry
A: Hey, blah, blah, blahing people is my job. Tell this guy to butt out.
I think I’d land somewhere in between, Terry. Lots of modern cars now use their computer to calculate when it’s time for an oil change. It factors in not only how many miles you drive but how hard you drive and under what temperatures and engine operating conditions.
If your car had that capacity, Terry, I’d advise you to simply abide by that. Those algorithms are pretty good. Unfortunately, your little iM doesn’t have anything that sophisticated. It just has a “Maintenance Required” light that comes on, mechanically, every time the odometer racks up 5,000 miles.
So you’ll have to do your own estimating. And it’s not an exact science. Like those modern oil-change algorithms, I believe the degradation of your oil is based less on the calendar and more on how much work, and what kind of work, you’re asking the engine oil to do.
If you were driving a cab or towing a team of Clydesdales, you’d want to change your oil more frequently. But by any measure, you’re putting very-light-duty use on this car. Even if you’re carrying a set of golf clubs and a gross of extra balls to hide in your pockets, you’re babying this thing.
If I were you, once I got outside of the warranty period,