The (fuel) brand is ok, you might try the middle grade (until summer) also colder temps tend to use more fuel - also next time you use an additive try STP gas treatment (the cheap stuff) It's actually cleaner burning (especially in city driving) than some of it's high priced competitors - due to it's isopropyl alcohol content. Only use it a couple times a year - enough is good, too much is just a waste. A good habit now & then is a good highway cruise also - they tend to load up the plugs when you do alot of city driving - remember, she's "long legged" for upper highway RPMs.