1994 honda civic ex 5 spd gas mileage
 

I am currently getting anywhere from 26-33 mpg. I have tried all different fuels/grades from different stations. Before I purchased the car, a new distributor was installed. I have installed spark plugs and a new fuel filter and am lucky to get 280-320 miles to the tank. I was thinking about swapping the engine out for a VX engine with vtec-e for the gas mileage but am not sure at this point.Does anyone have suggestions for me?

Oil is Mobil one fully syn. 5w30 changed every 4-5k, stock ECU (p28), 2.25 inch exhaust and stock air box

try a stock exhaust, 2.25 is almost twice the volume of the stock exhaust.
also check your timing.

X2^ That's too big of an exhaust pipe for a stock engine. Unless you plan on swapping out the intake and/or header for a less restrictive, aftermarket type, I'd downsize to 2" tops or go back to stock.

As for the engine swap idea, what condition is the current engine in? If you're willing to go through with it, I've seen those VX engines going for $400- $500 in my area.

The EX model came with a Vtec, just not the Vtec-e right? I checked autos.msn.com and they list 29/35mpg for the 125hp EX 5spd. What's your usual speed/driving style?

Hey 92hondacivic, make sure your t-stat is good. A cooler running efi engine uses more gas.

I dont drive it like my CRX. I dont "step on it" very often if any. I shift about 2500-3000, but it doesnt seem to help with the mileage.
I drive mostly on the highway (60-70mph) and over the last 5000 miles my average was 26-33. Havnt really changed driving style.

Driving style is the biggest single factor.

"When to shift" seems to be one of the main things that people who are new to efficient driving worry about, when they should instead be focusing on conserving momentum, reading traffic, and minimizing the use of the brakes.

Have you reviewed the list of 100+ driving tips to see what other techniques might apply to your situation?

yeah i would definitely slow down a lot and shift at no more then 2000rpms, I have a 2000 civic cx, no vtec and atleast 30 less horsepower and drive around just fine. also air up your tires if they aren't already at max sidewall psi

I have a 95 EX with an A/T, and I get better mileage than that. It's the kind of car that is fun to push the accelerator on, but you can get much better mileage if you restrain yourself. I've gotten close to 50 mpg with no mods other than restraint.

just replaced the oxygen sensor and noticed a little difference in the first tank that was ran through, but it fell on its face again after that. any suggestions?