Leave Standard or CRX HF 5 Speed

[samasaurus]

Hello I have just bought a 89 civic hatchback std. I am thinking of changing it to a 5 speed. But I see the 5 speed out of the civics has the same final gear drive as my standard. So I am looking at a 5 speed out of a CRX HF. It looks like it has the same 4 gears as my standard with the 5th a low final drive? Should I leave it stock? I have been looking for an 89 HF trans and haven't had much luck. But plenty of DX/LX 5 speeds out there would this save much gas? Please help me with my decision.

[GasSavers_Erik]

Where did you see that the 4 speed Standard trans has the same final drive ratio? I was under the impression that only the HF had the super tall final drive.

If you spend plenty of time out on the interstate, then the HF might be worth it. For city driving, you'd probably be better off staying with the STD trans.

[samasaurus]

The final drive are the same for the standard 4 speed and the regular 5 speed in the civics. The HF has a different final drive. This car will be doing more highway driving. Thinking of going with the HF. Dose anyone know where I can find one?

[GasSavers_Erik]

You can do a search on car-part.com. I found my HF trans for $75 using that website.

[FritzR]

I'd go with the DX. It would give you another 6% higher gear ratio with the 5th gear and they would be more evenly spaced. If you were feeling sporty you could swap the 5th out of the HF in there but leave the final drive that would give you another 8% higher gearing

If you want to go with the HF you should check to see if your engine bogs below 1500 rpm. It's a bummer if at the bottom of a hill you have to just about stop to get it in first. If it runs well and has some decent acceleration down there you would probably be OK and not be burning the crap out of your clutch trying to start out in 1st. I would go with the CA version of the trans if you go that way as the gearing is lower than the federal

[samasaurus]

Thank you that was a great web site I found one close to me with only 9,000 miles the guy I talked to said it has been sitting on the shelf for over 15 years. Thanks again. Its also the ca edition.

[GasSavers_Hal9000]

I posted a similar question to this recently. I've ended up settling on a DX trans and an HF final drive for my 88 crx DX (mine was an auto and needed conversion to manual). You might find this link useful for helping you figure out what rpm you'll be running in each gear depending on your transmission/final drive combo.

http://crx.honda-perf.org/math/index.html

In my case and with my tires, the DX trans/HF final drive puts me at about 3100 rpm in 4th and around 2600 in 5th at 75 mph. I've found that I get the best gas mileage between 3100-3500 rpm on the highway, so I figure that this will let me cruise in 4th at around 78-80 and be right in the butter zone. 5th gear I can use for any downhill driving I do (I travel between 7000 ft and 1000 ft altitude on a regular basis, so 5th will get used a lot) and just almost idle down the hills. By comparison, the HF trans/HF final drive would drop my rpms by about another 500 or so, and the DX trans/DX final drive would raise the rpms by about 700-800 rpms.... Hopefully this combo will give me the best compromise for my stock DX engine.

[samasaurus]

my 89 Civic HB now has an 89 CRX HF California edition 5 speed. I drove around town a little and then to work in back and put on about 200 miles and got around 41 MPG. Was hopping for a little better but it still need an alignment. so I hopping that helps a little. The final drive is 3.25 witch is the same as the vx(I believe). so I am going to call it an 89 Civic VX.

[GasSavers_Hal9000]

I'm getting about 37/46 with my '88 CRX auto. I'm hoping to squeeze a few more mpg out of it with the manual trans. I drive super conservatively though, plus your HB is heavier, so I wouldn't expect the mpg to be as good. Also, the VX's had a different engine, so I wouldn't expect your mileage to be as good as a VX.

41 is nothing to sneeze at though. I've seen lots of Honda owners (including the prev owner of my CRX) do worse. I bet that you can improve on it by tweaking your driving style, aerodynamics, and some mild weight reduction.