Comments on: Choosing a Fuel Economy Transmission

By: La honda a moteur a essence la plus

La honda a moteur a essence la plus — Sun, 15 Mar 2009 14:24:04 +0000

[...] que les rapports de transmission de la tranny de VX sont les plus courts SAUF ceux de la CRX HF. crxMPG - Gas mileage never looked so good Choosing a Fuel Economy Transmission [...]

By: La honda a moteur a essence la plus

La honda a moteur a essence la plus — Sat, 14 Mar 2009 08:40:31 +0000

[...] que les rapports de transmission de la tranny de VX sont les plus courts SAUF ceux de la CRX HF. crxMPG - Gas mileage never looked so good Choosing a Fuel Economy Transmission [...]

By: Benjamin Jones

Benjamin Jones — Mon, 24 Nov 2008 18:50:22 +0000

Tim -

It’s fine for me. I’ve never been in a situation where I needed to accelerate away from danger, in any car, so I can’t comment on that.

Mitch -

I’ve not personally tried, but you can ask around ecomodder.com since I’m sure someone has.

By: Mitch Hayes

Mitch Hayes — Mon, 24 Nov 2008 18:28:30 +0000

I am still wondering if the HF trans will not help my in town mileage with the D15b2 16 valve in my 89 CRX. I understand that the VTEC d15z1 is definitely aimed at low speed power, but I don’t have this engine (at least not yet). Dropping the final drive from 3.88 to 2.95 will likely help mileage on the hwy, but in town, I wonder about it due to the lack of torque multiplication. This reminds me of the 1970s with American V8 cars. After the 1973 oil crunch, Detroit started putting crazy axle ratios in their cars. I have seen 2.56 and 2.41 rear gears. We found out that going from a 2.73 to a 3.73 did not tend to change in-town mileage much. Hwy mileage is different because it is steady state driving. Have you tried the HF specifically with the stock DX dual point non-VTEC engine, and, if so, what were your results? Thanks for doing this site. It is really helpful.

By: tim

tim — Mon, 24 Nov 2008 16:27:02 +0000

Looking to buy a vx and put in a tranny like you did.. How is city driving with that transmission? How much is the engine struggling at those shift points? Can you romp on it in an emergency?

I just dont want to focus on high gas mileage and end up with a car with zero power.

By: Benjamin Jones

Benjamin Jones — Wed, 30 Jul 2008 18:42:09 +0000

I actually don’t have a VX, but the CRX I talk about here has gotten that engine swap. The VX and crx si weigh about the same amount, anyway, though the CRX has better aero. You could definitely duplicate my numbers. Look for my swap post in a day or so (kind of involved writeup).

Ben

By: Paul Anderson

Paul Anderson — Mon, 28 Jul 2008 18:55:55 +0000

I took a look at some of the Civic VX photos. The look of the CRX is what I really want. If the HF trans will work in your car, could the engine not work in the CRX? If so, the SI being I think 600-800 pounds lighter, could I pull the kind of numbers you’re getting? Or better? By the way, what year is your VX and which engine does it have?

Thanks Again,

By: Benjamin Jones

Benjamin Jones — Mon, 28 Jul 2008 17:30:02 +0000

Hey Paul -

I think you’d do well in the 40s with the si engine and hf transmission, though if you go all out and do a civic vx swap with the hf gearing you can get in the 60s (like me).

By: Paul Anderson

Paul Anderson — Mon, 28 Jul 2008 17:23:11 +0000

Hi Benjamin,

I am wanting to purchase a CRX. I have always wanted one, and know the HF model with the 1.5L to be the ultimate gas mileage machine. I’m thinking about an ‘89-’91 model, but I find tons of Si’s, but almost no HF’s. Would you be willing to speculate on the mileage of an 1.6L SI with the HF Trans, and will this swap work? Any help would be greatly appreciated.

Your Friend,

Paul
Boca Raton, FL

By: Benjamin Jones

Benjamin Jones — Tue, 22 Jul 2008 19:42:38 +0000

I’m running the Civic VX, d15z1 right now, actually. You’d be fine with the HF tranny and shouldn’t need to worry about manifold vacuum. Both would be ideal, but the HF tranny is definitely worth the effort, I think.

Thanks for commenting.