someone put reg in my gt v6 premium only gas car is that a problem
Not a big deal but you might have some pinging. When you get to a half tank, fill it with premium and then again when it is empty.
If you are worried about it put in a can of octane booster which you can buy at an auto parts store.
Looking for a Used Eclipse in your area?
CarGurus has 1,191 nationwide Eclipse listings starting at $1,999.
Search Mitsubishi Eclipse Questions
Mitsubishi Eclipse Experts