I own a 2015 XT.

Spark plug service interval is 60,000 miles.

Mine was done for the second time two days ago at ~117,000 miles.

Logon to the MySubaru website --> Vehicle Service & Maintenance --> Maintenance Schedule

 

PDF of the maintenance schedule is attached.

 

60K miles. They will last longer, however, if you shoot for 60K, there is some leeway if you forget. I recently changed mine with 80K on the plugs. The car was running fine, but the gap was wider than specs. I had the extra plugs in my took chest for a year, and had just spaced it off.

 

Keep in mind that worn out plugs (worn electrodes, wider gap, etc.) will cause the coils to work harder, increasing likelihood that one or more will go bad.

Its best not to wait too long.

 

Keep in mind that worn out plugs (worn electrodes, wider gap, etc.) will cause the coils to work harder, increasing likelihood that one or more will go bad.

Its best not to wait too long.

Thanks for the good info, it’s helpful and I’ll be sure to have the plugs replaced at 60K based on your comments!

 

I change mine at 40000 only because I'm afraid of having them seize in the head if I wait until 100000. I've changed mine twice in 80000 miles and it is a pain to do. Each time I replaced them the old plugs looked pretty good. I go a little overboard with preventative maintenance.

 

I just pulled plugs with 43,000 miles on them from a '15 XT because chemical intake cleaner had just been used and then the valves were walnut blasted. A bunch of other maintenance was being done and so the plugs were replaced. The new plugs were on hand and I was curious how the ones in the engine looked.

The vehicle has 117,000 miles total.