Only getting 42mpg in my 1990 CRX HF

[dylanu]

I shift from first to second at about 1800 rpm then second to 3rd at about the same thing then from 3rd to 5th i follow the shift light while using hypermiling techniques but im still only getting 42mpg. its only got 120k miles. what could i be doing wrong and what can i do?

[1.5Ldave]

It may not be you thats at fault. Whens the last time you did a tune up on it? New spark plugs, o2 sensor, rotor, cap, wires. Was the timing belt changed? Check the cat see if its melted at all. Run a bottle of fuel system cleaner. And try some sea foam or other brand of carbon cleaner to break down whatever desposits it has built up in the motor.

If it has an aftermarket intake make sure its pulling warm air from near the exhaust manifold, these civics were built that way from the factory, its what it wants.

And of course, check the tire pressure.

Another thing that I think helped with my mileage was adding Tufoil. I dont know if it actually improved the mileage, but it definately lowered my rpms a bit. I suspect this is more of an effect on older cars that were built while oil still had PTFE in it. Oils today dont have (or a very miniscule amount of) PTFE, which can make a real difference in how the motor behaves. Whatever makes it work, im a believer.

[MetroMPG]

Shift RPM is a relatively small item on the list of techniques for improving fuel economy.

I'm with 1.5Ldave - I'd want to first make sure the car is in a good state of tune before anything else.

Then I'd want to know what kind of driving you're doing - mostly city or highway?

[dylanu]

alright I will try the tuneup idea. And the rpm thing isn't the only thing I do. Its mainly hills that kill me. How my much is a tuneup? I only do 100 percent city driving. Anyone know where I can get a supermid or a scangauge

[Daox]

Have you read over our 100+ hypermiling tips yet? I'd highly suggest it. Your car is capable of incredible city mileage.

For starters, you need to keep off the brakes. Avoid using them as much as possible. Second, for those hills I would be using lots of throttle but stay in a high gear going up the hill and coast down the other side in neutral. At longer stop lights I'd recommend turning the engine off. Other than that, I'd make sure you clean out any unnecessary stuff from your car to reduce weight. In stop and go weight is a real killer.

[dylanu]

i just read all of them and do most of them already. i guess the only thing i can turn to is the tune up. i pulse and glide, i *never* use brakes, and do turn off my engine at long lights. does anyone know what kind of mpg gauge i can get and a guide to installing it?

[i_am_socket]

You may want to check out the MPGuino

[dylanu]

where can i buy one already made

[Wonderboy]

Heh. 42mpg isn't so bad then, eh?

You kind of have to be willing to do things like go to the extreme to change your driving techniques, perhaps make some mods on your car, and learn to solder to wire up your own instrumentation. I can't speak for everyone around here, but I can't imagine anyone willing to build one for you, but I know from building mine that everyone is very supportive and helpful in every step along the way. Be prepared to spend about $50, several hours of research, and several hours of wiring/testing. Maybe an hour of downloading the Arduino software too

Good luck

[Kaneda]

im also with dave on the tuneup... you have a world of options with the rex, i have an '88 hf and before mine died of rearend cancer.. i could pull 50+mpg doing courier service easily.
im currently working to build it back up topping out at 1400lbs... full interior stock looking...
good luck