CarTalk.com Best of Deals Car Reviews Repair Shops Cars A-Z Radio Show

Oil change interval twist, time between dumps

I know the mileage side of this question has been talked to death. What do you guys think about oil change time interval? I have a number of older vehicles that sit in storage. I drive maybe 1500 miles a year on any of them some much less. I change the oil once a year before winter sets in and they sleep over the cold months. I haven’t had a problem yet but am I asking for trouble?

This question also goes for newer cars. Due to unforeseen reasons, my wife’s Dodge Magnum has 3200 miles on it in for almost a calendar year. It is full of the dealer synthetic blend, what ever that is. It will get changed tomorrow but how long is too long time wise?

I have heard of damage to bearings because of the acid in the oil. But what is the real reasons here?

I think you are fine at once a year in the classics… On your Wife’s car you may want to do once every 6 months to be super safe, but even then once a year should be OK…

A year just slipped up on me with her car. I meant to do it at 6 months but things just got hectic

I think the time interval is meant for cars that are driven frequently. That usually means they are subjected to short drives, stop and go, etc. That causes the acid build up that you are concerned about. If you drive it infrequently, but drive at least 7 miles when you do drive, then you can go longer. I go as long as two years on my truck.

I’ve changed my interval to once a year on my idle car. I used to change twice a year with the seasons since it called for different winter oil, but it takes 8.5 quarts plus a filter and last change I had only 100 miles on it since the last change. It just seems senseless to change it twice a year.

I’ve gone two years on my 79 too and see no issues.
In fact it’s been two years since the previous gas fill up too. With Staybil in the tanks it continued to run great untill the next fill up.

I have a '97 Ford Escort that I bought new and is used mainly when driving long highway trips. I change the oil in it every 3K miles regardless of elapsed time. It’s currently 15 years old with 32K miles and has had 10 oil changes since new so it’s averaging an oil change every 1.5 years. As long as the driving you’re doing is getting the engine up to operating temperature so it can burn off moisture I wouldn’t worry about the elapsed time. I have new/old stock oil still in the bottles in my garage that’s 10-20 years old and is what I use in all my cars. I see no difference in whether it’s sitting in the oil pan or in the original bottles.

As you can see, nobody really “knows” the right answer, if indeed there is a right answer. So I can suggest you continue doing whatever you have been doing all along. There is nothing to worry about.

Once a year should be fine, based on your driving habits. I would stick with synthetic oil. I would also make sure the coolant gets changed. Old, depleted coolant sitting in a vehicle will eventually rot out the radiator, heater core, and other components.

Once a year on the classics that sit in the winter is fine. On the Magnum, that seems like a low miles per year car and likely most in town stop and go miles. 6 months intervals for the Magnum would be best, but likely no big harm done by missing an interval and changing now at 12 months.

For the Magnum I’d go with regular oil to save a few bucks, and stick to the 6 month interval for changes.

I have several vintage cars as well that are only taken out for local cruise nights and to get ice cream.
They may see 500 miles a year and that would be a lot (hey, we like ice cream). They are usually not driven in winter.
The oil is changed when spring hits.

watch witch oil you use in newer cars there is adiffernce in the oils chech the back of the bottle and look at the round thing you our looking for the “SL” or sm sn don’t put a lower letter then what the car wants in the engine. you can use l in a car that calls for e. S is for gas powered cars and C is used in diesels

@UncleTurbo
The Magnum makes 11 to 12 mile trips when it is driven. My wife took over the Crown Vic we got for our son’s first car because aesthetically it doesn’t matter if it gets dinged at work and doesn’t matter if chewing gum gets stuck on it at the elementary school drop off. That is why it has stayed low. My son is now driving more and she will be back in it more often so this is just a curious question.

@Big Marc
This is the only car I have that I let the dealer do the oil changes on. Give me a hard time on that if you want to… The type of oil should be what the dealer/ Dodge stands behind. Now, I won’t get into why this car is the only one but I have my reasons.

Interestingly, the service adviser told me this morning that the car can go 5000 miles between changes. I told her the time limit was why I was changing instead of the miles this time around. When talking with the actual tech that was changing the oil regularly, he said the oil was really dark at the one 4500 mile mark I brought it in and suggested if I was going to keep the car I should be following the severe duty cycle. That was before the Crown Vic came on the scene.

oblivion makes a very good point about the coolant. While the coolant itself does not deplete, the corrosion inhibitors do because even if the engine is not running, corrosion is always at work. For your older vehicles, and oil change every couple of years should be fine, once a year on the Magnum.

strike my remark on the Magnum if you are going to be driving it more.

Coolant was changed at the last oil change one year ago.

“For the Magnum I’d go with regular oil to save a few bucks…”

+1. Mineral oil is fin in this car. BTW, my neighbor gets a new business car from his company every 2 years, and he was all hot to get the Magnum until his kids said it creeped them out - looked too much like a hearse. I like the Magnum, too. I just thought it was a funny story.