I own a 2000 Prelude w/ the stock H22A4 & a short ram intake. The car has 114k miles on it. I drive a combination of hwy/city (more hwy than city) & am averaging 32-34 mpg. I drive 10 miles under the speed limit on hwy (55 in a 65), and never rev my engine past 3k rmp's. I started using BP gas w/ invigorate crap. I have only owned this Prelude about 6 months and the previous owner used 5w-30 full synthetic oil. It used a bit of oil (typical H22) and was tired of spending over 6$ every 2 weeks on oil. I contacted the Honda dealer and they said it would not hurt anything to switch to conventional oil, so I switched to Valvoline max life 10w-30 a couple of oil changes ago and noticed a decrease in oil consumption & an increase in gas mileage. I have ran the car up to red line probably 5x's since I've owned it & it seems to pull like it should. Is it actually good for the engine to hit VTEC every once in a while to "clean out the cobwebs?" ? I know it is w/ a turbo car so the waste gate doesn't freeze up and won't boost fully. Also, I have an APEXi world sport cat-back exhaust that I am considering installing. Would the exhaust have an effect on gas mileage? I changed transmission fluid & put in syncromesh. I think that helped a bit. Is there anything else I can do to improve mpg? I do use AC quite often because it's not worth being miserable. Something I would like to do is install a 5th gear from either an F22 or an H23 to reduce rpm's. Any thoughts/suggestions would be great. Don't get me wrong I am VERY happy w/ the mileage I'm currently getting, but I would like to get 35+ if possible. I'm just being greedy. I'm not one of "go green" crazed people. Thanks for the help. BTW my tires are inflated to 45psi (max is 51psi on these tires).

 

Well for a 5th gen to be getting that type of MPG well, id say that you are one of the luckey ones. Its very good miliage to begin with.

A new muffler wont increase MPG either

 

thats great mileage in my opinion... just keep up with your tune ups and your golden. i noticed great increase when changing plugs, flushing out coolant. after oil changes, replacing tires. taking out excess weight in the car.