The 2001 Acura RSX (not a Type-S, unfortunately) gets 27 MPG in the city and 33 MPG highway (better than the Type-S, actually). The gas tank is 13.20 US gallons.
I have a K&N cold air intake on my RSX, which has increased the MPG to 30 city and 36 highway. Not too bad for a quick sports car with a little 4cyl and manual transmission. The K&N filter also gives a noticeable horsepower increase and a nice throaty sound in the engine since it’s not a muffled. It probably lost a pound or two of weight, but that’s minor.
Every year, I try to do one sort of upgrade to the car. I’ve tinted the window and added this filter so far. I’m not sure what to do this year. It may just be a good detailing, which it needs. It did get new paint last year because of the hail damage.
Some things are starting to wear on it, too, now that it’s over 7 years old. The headlamp covers are foggy (I’ll be working on that), there’s a catalytic converter cover that’s rattling a little and the dealer thinks it needs a new clutch mast cylinder but I don’t think it needs it. So the upgrades this year might not be fun ones but instead maintenance type things and things to help it look good and run well into the future.
My dad asked me when I think I might get rid of it and I said never. I think I might hold onto this a long time if I can. It’s a great car and could be a collector eventually since they’re not made anymore.