The 'when' of oil changes - use mileage or time?

On our cars if 5k mi or less interval I go by mileage. If it is 10k mi or higher interval I will change every year. My wife's C-MAX Energi will go two years or 20k miles, but that is the exception.

 

I would go with the once a year minimum.

If it was Canadian 3rd gen, the interval is 6 months or 8000 km (5000 miles), whichever comes first. In that case, with super low miles, I might go to the one year interval.*

For a counterpoint, Honda uses a Maintenance Minder now, has no published schedule. In the Owner's Manual it says to change the oil (or oil and filter) when indicated by the MM. There's a proviso at the bottom of page, saying, even if the MM has not come on, do and oil and filter change at least yearly.

* That actually is our situation, but I'm DIY, and retired, time on my hands, so I continue to change oil and filter at 6 month interval. FWIW, if I compare the drained and new oil, even with our low mileage there is a marked difference.

 

i don't know if there are any studies. you'll get opinions both ways. i would say if you plan to keep the car beyond 100k, or want to take care of it for a future owner, do it yearly. otherwise, every 10k is fine.
another thought is to change the filter yearly.

 

What would be the reason behind changing the filter yearly? Does it break down just being immersed in oil?

 

i only do 3,600 miles a year in hybrid mode. i change it every spring, but my mechanic said every other tear would be fine, but i don't know what he's basing it on.

 

no idea. probably not. when you think about it, the usual recommendation for yearly changing is due to condensation, so leaving the filter and changing the oil might be a better idea.

 

I did some research before your reply. The answer to filter degradation over time was indeed water being trapped in the oil, and thus in the filter. It appears that water causes breakdown of cellulose filter media, but not synthetic filter media. So a good oil filter with synthetic media, such as Mobile 1, should last as long as the oil. And it seems like, to me, if there is enough condensation (water) in the oil to cause a cheaper oil filter to break down, I don't think I would want that oil or filter sitting in my engine for extended length of time.

I would change oil and filter annually if I didn't hit the mileage first.

 

That's Honda's policy. Oil change is service A, and oil/filter change is service B, on the Maintenance Minder. The A & B services always alternate: A one time, B the next. However, trying to get a Honda Service Department to go along with that, they'll call you nuts.

 

Everything in our "fleet" clocks more than 5000 miles per year so I go by mileage for the Prii and the FFH. The F150 gets an oil change about every six months. The antiques get oil changes once a year - less than 500 miles per year typically.

 

Porsche says 2 years with Syn .... that's what I do with all my cars that are not driven often. I use a quality filter .. normally OE/ M