I'm interested to see what other HX owners are getting for MPG. I picked up a 99' HX a few months back for a DD. It's completly stock and staying that way.

After working out a few CEL issue it had she been pretty normal beside the valve lash that I can't seem to get rid of.

I'm getting 430-460 mile to the tank. I tried hypemilling the last tank and got it up to 518 miles LOL. The most gas I put into it was 9 gallons, haven't tried to run it down until the light came on yet. I also running 93' octane too, notice a big different in MPG from 87.

 

You shouldn't be able to tell a difference in the octane if A: your not "giving her all she's got Captain" and B: your not modding it at all. The only thing it will do is lighten your wallet, however that might make you save some MPG if you pay for gas with pennies!

 

The octane shouldn't change anything in that car. That's amazing mileage by the way.