Should I do some preventive maintenance on my 10 year-old-car?

I bought a new 2012 Subaru Impreza Sport Outback while I was still working and piling on the miles. Then I retired and now only put 5000 miles or less on the car each year. It currently has just over 100K miles and is in excellent shape except for the gas gauge not working properly. I would like to keep this car another 10 years before I consider retiring it. So, should I invest in some preventive maintenance in addition to the regular oil changes? The dealer advised not fixing the gas gauge as it would be very expensive and I can calculate when I need gas based on the number of miles driven. The downside with that is the check engine light comes on and I wouldn’t know if it came on for another reason. There’s also some expensive mileage maintenance–I missed the 90K check, but it looks like nothing gets replaced unless it needs replacing. Are there certain things that I should have replaced just because of the car’s age?

It seems your car is not a 2012, perhaps a 2002? I believe your motor has a timing belt. If so, you need to have the timing belt replaced which also includes a new water pump and belt tensioner. If you’ve never had fluids changed then you are overdue for new coolant, brake fluid, power steering fluid, transmission fluid, differential fluid, transfer case fluid.

New spark plugs might be nice, and new air filters. It is not likely you’ve simple done oil changes and nothing else over the years. Perhaps you need to check your old service receipts and records. If you don’t keep them, then start now so you have a record of what has been done to your car. Keeping a car for 10-20 is really all about keeping it serviced properly over the years.

If the body is in good shape, and the seats hold up, it’s always worth keeping a car running that runs well now. Expensive maintenance is just that of you have the dealer do it. Take it to a good independent you can trust with Subaru experience, and go by the manufacturers maintenance. Nothing you can do will cost you more then replacing it. It oly becomes questionable when the body starts to rust and becomes unsafe.

Subaru sells this $10 bottle of “Subaru Coolant Conditioner” that is said to help the system so it is less prone to having head gasket problems. I guess they came up with this stuff after they had their spell of head gasket problems with cars made around 98-02. Tiny weep problems it is supposed to plug.
From what I’ve read, it appears to help. One can actually add it to any Subaru even if you don’t drain the system. It is what Subaru suggests doing.

If you are due for a timing belt/water pump change, they’ll have to drain your coolant anyway. Ask them to add it or add it yourself, should you get the timing belt done by an independent mechanic. It seems to be cheap insurance.

This era of Subaru engine is prone to head gasket leaks. Check with your dealer and see if they have any history of head gasket repair on your car–or you may have that in your records.

The timing belt/water pump maintenance is essential. It’s not an investment, it’s a required expense unless you want to be driving a car that may quit running at any given moment. Other than that, some fluid and filter services and just routine maintenance should keep you running for some time to come.

What exactly is this expensive maintenance that you mention? Regardless, if you want to keep the vehicle running for many more years, of course you need to do everything listed in your owner’s manual. They didn’t put those requirements in there for fun.