Oil Change after 1 year?

Hello all,

I just recently got back from a deployment, and just finished my 4 years of active duty in the military. As a result, my 2012 Subaru Legacy 2.5 hasn’t been driven much this year. I currently have 5,500 miles on it, and am running subaru full synthetic oil. I have been changing it every 7,500 miles. I have read that I should change it one year or 7,500 miles. The car has sat in the garage, with occasional light driving by my parents to keep the fluids moving.

Anyway, does oil get super dirty after a year? I know that it recommends 1 year, but would I be really stupid to push it another 2-3 months until I am at 7,500 miles?

Thanks all!

Light driving (short trips) can be bad. Change it.

Will do. Just wanted the pro’s on here opinions. Also, why do they say 1 year or x amount of miles? Does the oil all of the sudden get dirty after a year?

I’ve stored vehicles longer than that with conventional motor oil without being driven at all and have never had a problem putting them back into service.

But have the vehicle checked out to make sure it’s road-worthy.

And thank you for serving for our country.


The oil does not just suddenly get dirty or break down. If the people who designed and built the car say what to do why not just do it.

totally agree, Volvo, and will be doing an oil change ASAP… I was just curious why it’s 1 year or x amount of miles. I didn’t know if oil broke down after being in the engine for that long…

The time is to cover low miles from lots of short trips. Those put water in the oil that doesn’t get boiled out, leading to more contamination.

In my opinion 7500 miles is a little too long between changes, independent of how many months it has been. This is especialy true if you vehicle sports variable-valve timing. I agree w/the others advice here, now’s a good time to change it out and install a new filter. Sticking with the oil Subie recommends for your car is an excellent plan. Good time now to check w/Subie dealership parts dept to see what they charge for OEM oil filters too. Sometimes the price is about the same as a retail chain auto parts store aftermarket filter. If so, an OEM filter is the way to go. I wouldn’t extend oil and filter changes beyond 5K. 3K if you want to play it extra safe.

And thanks for your service to your country, and welcome back!

Any oil change is a good oil change. Sure do it wether you need it or not. Given the few miles I would add some sea fome or techron just cause I like to spend money on stuff that might matter.

I’m sure it would be ok but I change at 5000 with full syn. With the oil minder at about 50%. Welcome back and thanks.

Pull the dipstick. Put a drop of oil on your forefinger and rub with your thumb.
Does it feel smooth, or any slight amount gritty?
How does it smell?
Then get it changed.

I currently have 5,500 miles on it, and am running subaru full synthetic oil.

When you do get the oil changed…do yourself a favor…and just go to Wallmart and buy any full synthetic they have. Subaru doesn’t make oil. It’s made for them by one of the oil companies…but if Subaru is like other manufacturers…they charge 2-3 times the price.

“buy any full synthetic they have.”

But it should meet Subaru’s specs, whatever they may be

Some manufacturers have specs, beyond conventional versus synthetic and viscosity

The european auto manufacturers and GM’s dexos comes to mind

But it should meet Subaru's specs, whatever they may be

I’ve yet to see any modern synthetic oil that doesn’t meet or exceed all manufacturers specs. As long as it’s correct weight…it should be fine.


There are plenty of synthetic oils that do not meet Dexos or european auto manufacturer’s specs

You could argue that europeans are only a small part of the market, but GM is a big player


There are plenty of synthetic oils that do not meet Dexos or european auto manufacturer's specs

Yup…there are, I misspoke. MOST American and Japanese manufacturers still use the API standard…Europe and GM have their own standard.

But my comment about pick any synthetic oil is still valid for his SUBARU. No special formula…just synthetic and the correct weight.

Thank you for your service @Jman136.

When an engine is started cold, a small amount of water from the humid air is drawn into the engine block and settles in the motor oil. As the you travel down the road the engine and oil heat enough that the water evaporates and is expelled from the oil.

Your family…taking only short trips around the block and such, did not heat the oil enough for the water to be expelled. We are talking only small amounts of water, but it adds up over all those short start-ups.

I’d just get the extra oil change to be on the safe side.


I second Barkydog . . . do an oil and filter change (full synthetic) and add a bottle of Techron, you’ll be fine. Welcome home and thanks for your service to our great country! Rocketman

5,500 miles is reasonably close to the max recommended 7,500 miles. (which seems a bit long anyway) I would just get it changed and enjoy the peace of mind. How much is waiting going to realistically save you anyway?

Most people do about 28 drive cycles a week on their vehicles. A drive cycle is a cold start to fully warm and back to cold after shutdown. A short drive cycle that barely makes it to warm and is then shut down will cause moisture to build up.

A longer drive cycle that “dries” out the oil has a different issue. When the engine is shut down, a film of oil is left on the interior parts of the engine and that film has to absorb all the residual heat from the engine. This is the most damaging thing to do to the oil. At the next start, this film will cause most of the wear to occur in the engine.

If the oil is fresh, the film will just be a sticky goo at the start up so only a little extra wear occurs, but as the oil ages, the film can become abrasive, so it is important to change the oil before reaching this point.

The time limit on the oil life is based on 28 short drive cycles that don’t add up to the total mileage. If you parents only drove the car once a week or so, and if they drove it at least 7 miles or more each time they did drive it, then you have only a few drive cycles and the moisture should not have built up. If both of those conditions are met, you can safely go to the 7500 mile interval.

If you have any doubts about either condition being met, the change the oil and sleep better at night. BTW, I have used the 7500 mile interval on all my vehicles that use synthetic oil and have never had an issue with engine life. I’ve been using synthetic for over 30 years now and typically keep my vehicles over 200k miles.

Your model Subaru does have issues with excessive oil consumption due to rings. I suspect they had a bad supplier, but not all 2.5 engines were affected, only a few and Subaru will fix them for you if you have an issue.