HF transmission swap

[MPGustafson]

Hello there, havent chatted in a bunch of years. I have a 1990 Honda civic LX with a d15b2, doing a complete engine rebuild currently. I have an 88 CRX HF transmission, with flywheel and transmission. I was curious that if i swapped this in if it would increase my MPG at all? Any bit will help, its a commuter car and ill never be stuck in traffic.

Any info would be much appreciated!

[Daox]

I'm no Honda expert, but if I recall correctly the CRX HF is one of the tallest geared Honda transmissions. Assuming my memory is correct, you will see a fuel mileage increase with the HF trans. Exactly how much is anyone's guess.

[hondaguy72]

The lx transmission is geared pretty tall to begin with. The hf Trans will be taller gears. When matched with aero mods you will see quite a bit of improvement. Without the aeromods it's not enough economy gain to be worth the driveability penalty in my opinion.

[Daox]

You certainly will see gains with or without aeromods. The taller gearing will increase load on the engine and lower the brake specific fuel consumption. Aeromods will definitely help, but taller gearing will definitely help with or without aeromods.

[Gasoline Fumes]

I put an HF transmission in my Wagon. I'd never go back to the original transmission.

[30mpg]

For city commuting I recommend a battery swap , takes less force to get the car going after a complete stopp.$40 Lightweight battery - YouTube