2007 G35 Coupe
Hey guys perhaps a dumb question. I live in NH and store my G winters. I have the oil changed with Mobil 1 synthetic every spring when I pull it from storage, but I'm putting less than 500 miles on it per year. I also have an extended warranty for whatever that's worth. With my mileage (69k) the manual says change the oil every 3 months or 3,750 miles. Do I really need to change the oil every spring or am I wasting my money?

 

Yes you should change oil at minimum once per year (some sources say twice per year). The reason is the system is not ENTIRELY enclosed, you still get a little bit of condensation inside the engine, yes it cooks off when the engine is up to temp but over the course of a year your oil will get contaminated with moisture, blowby gasses, etc.

Some sources now say twice per year, I haven't seen any scientific data to prove this, you could always have a blackstone oil analysis done at the end of 6 months, then at the end of 12 month (using the same oil, you can feed a 1/4" clear tube down the oil fill neck and pump it back up from the dipstick if you don't want to get the car up on a lift), then compare the wear and decide if you want to stick with 12 month intervals.

 

I'm in a similar situation as you (except mine has higher mileage), and I just change the oil in the spring. Hopefully with COVID restrictions lifting I'll put a couple thousand miles on it this year instead of a couple hundred.

 

With only a couple road trips last year, I haven't been putting much on my car either. By the time I hit 7500 miles (I use Penzoil Platinum Plus), it will likely be more than a year since the last oil change. Changed it in July, only driven it 3500 miles since. So I'll change it in July.

 

Sounds like the ~$70 it costs to get the oil changed every year is well worth the cost. Thanks for the replies/advice!

 

For what its worth my 08 g35x with 150k runs noticeably smoother after switching to Mobile 1 high mileage full synthetic. The car is stock and still a amazes me with its power at 150k. Knock on wood 🪵🤣👍🏼