Best Mod to Date - Trans Swap (1997 Civic HX)

[PAFirefighter11]

I purchased my '97 HX with an SI trans in it. My MPG was pretty low for what I expected. I finally had some free lift time so my buddy and I swapped the stock trans back in (It was included separate with the car):



I've been logging the fuel since day 1. It's easy to tell the before/after of the trans swap per my log:


Currently running 10w30 in the trans to clean it out (some minor debris looked to be in there). I have 2 quarts of Honda MTF that I'll be putting in once I drain this motor oil out.

I'm also planning on doing the grille blocks, raising the car up (Coil overs are too low), then doing an air dam, rear bumper cover underneath, cleaning the EGR system, and some other basic modifications.

[mcrews]

I would love to swap to a different tranny in the sportage (there is a better geared one out there) but car is short term
Nice job!

[MetroMPG]

Nice work. Were you nervous at all about how it would affect the car's driveability/character?

I was fairly reluctant to do the trans swap in my Firefly/Metro (but I also went far beyond, going with a tall final drive that was never intended for the 3-cyl drivetrain). And now I want an even taller top gear.

Did you already have the HX trans on hand?

(EDIT: added this to the home page.)

[mcrews]

Originally Posted by MetroMPG

......... And now I want an even taller top gear.

.....do 'dubs'!! (22" )

[PAFirefighter11]

Thanks guys!

Originally Posted by MetroMPG

Nice work. Were you nervous at all about how it would affect the car's driveability/character?

I was fairly reluctant to do the trans swap in my Firefly/Metro (but I also went far beyond, going with a tall final drive that was never intended for the 3-cyl drivetrain). And now I want an even taller top gear.

Did you already have the HX trans on hand?

(EDIT: added this to the home page.)

I wasn't too worried about the car driving differently. I knew it'd tach lower at highway speeds so that was my main concern with the swap.

When I purchased the car the prior owner gave me the stock HX trans and some other stock parts. The first time I took it out I realized it revved very high: With the SI trans it was around 3500 RPM at 65 MPH. With the stock HX trans it went down to 2900 RPM at 65 MPH.

After running through my first full tank with the HX trans I was very, very happy with the results and the FE boost. Looking forward to even better FE in the future.

[mcrews]

Rick,
Wow 3500 is crazy.....that would give me a 'buzz' headache at the end of a trip!!!

I realize the little 4 bangers need to rev higher, but as a reference, w/ taller tires, I was at 1850 rpms at 65mph in the Infiniti Q45 (4.5 liter V8)

[PAFirefighter11]

Originally Posted by mcrews

Rick,
Wow 3500 is crazy.....that would give me a 'buzz' headache at the end of a trip!!!

I realize the little 4 bangers need to rev higher, but as a reference, w/ taller tires, I was at 1850 rpms at 65mph in the Infiniti Q45 (4.5 liter V8)

It is super high! The SI/EX have the same trans and they both tach around that RPM at 65 MPH.

Not too shabby. My 1998 Jeep Grand Cherokee 5.9L tachs at 2300 RPM at 65 MPH on 32" tires. My Trans Ams tach around 1800-2000 at 65 MPH IIRC. Two overdrive gears in the T56 (6 speed) trans really do wonders.

[Cobb]

Drop 10mph and you will get closer to 50 mpg.

[PAFirefighter11]

Originally Posted by Cobb

Drop 10mph and you will get closer to 50 mpg.

I'd love to but that's basically impossible. Not sure how it is down there but up here I'd get run off the road. The speed limit is 65 & 55 respectively on the 2 main highways in my daily commute. Most people do 80+. The way it works here is if you aren't at least 10 MPH over, even in the right line, you have people within inches of your bumper, passing you and cutting you off, and just overall reckless behavior. This includes tractor trailer drivers especially since you're in "their" lane and they need to switch over to the left or center lane (if applicable) to pass you.

With that said, I do 65 MPH the whole way, on both the 65 and 55 zoned highways. The 65 has 3 lanes, the 55 has 2, so that speed works well for both.

[1slw4dr]

Originally Posted by PAFirefighter11

I'd love to but that's basically impossible. Not sure how it is down there but up here I'd get run off the road. The speed limit is 65 & 55 respectively on the 2 main highways in my daily commute. Most people do 80+. The way it works here is if you aren't at least 10 MPH over, even in the right line, you have people within inches of your bumper, passing you and cutting you off, and just overall reckless behavior. This includes tractor trailer drivers especially since you're in "their" lane and they need to switch over to the left or center lane (if applicable) to pass you.

With that said, I do 65 MPH the whole way, on both the 65 and 55 zoned highways. The 65 has 3 lanes, the 55 has 2, so that speed works well for both.

I'm about to drive up to York to pick up an HX for my daily commute. Here in North VA it's the same. Hell when I lived in Orlando it was as well. People get mad as hell especially when people drive to slow in the left lane. It's insane. I can get like that at times too but if your doing 70 in a 55 there is no reason for someone to be getting mad lol but that's how it is.