Civic transmission identification and tire size

[cems70]

Does anyone know how to truly identify a '92 - '95 hatchback VX/CX transmission from a DX transmission? I'm aware there's a transmission identification number on the casing, but I found in my research that the VX/CX and DX transmissions all have the same P20/A00 code. So how does one distinguish them? I'm looking for a used one to buy and want to be sure I get the VX/CX trannsmission.

Also, if I swap my '95 DX hatchback DX tranny for either a VX/CX transmission OR change the final drive in my DX tranny, does that mean that the speedometer is now calibrated to the VX/CX tires (size 165/70/13) instead of the DX tires (175/70/13)? Thanks.

[SVOboy]

The odometer will not be messed with, so don't worry about that, the transmissions use the same VSS.

To figure out the tranny type you need to turn the input shaft and count the rotations to spin the differential around, but I'm not sure how many turns it takes for the EGs...sorry.

[cems70]

SVO, I'm new to the terminology. What's VSS and EGs?

If I understand you correctly, you're saying a Civic DX odometer won't register fewer miles with 175/70/13 tires and a VX/CX tranny? Everything I've read on these forums (I think) and elsewhere says that going to the 175/70/13 tire on a Civic VX/CX will show fewer miles (2.5% to be exact) than the original 165/70/13 tires. I assumed the same would be true if the tranny is replaced in a DX w/ a VX/CX tranny or if the VX final drive is installed into the DX tranny (giving it the same VX final drive).

[budomove]

vss-speed sensor

eg: 92-95 civic

[SVOboy]

Change in tires will alter the odometer but not change in transmission, I stink with tire sizes, so I overlooked that part, sorry.

[GasSavers_scostanz]

I did a CX tranny swap into my 94 DX and my speedometer/odometer actually became more accurate than with the original tranny. Must be variances with the VSS sensors. Essentially, your speedo/odo should be pretty close to what it reads now. I asked the same question as you when I was looking for my tranny....you can find the responses here

http://www.gassavers.org/showthread.php?t=1457

[cems70]

Scott,

Thanks so much for the info...exactly what I was looking for. By the way, what was you pre-CX and post-CX tranny swap fuel economy?

Steve

[GasSavers_scostanz]

Steve,

It's really difficult for me to quantify exactly but it was definitely worth it. I'm estimating it is at least 5 or 6%. You can look at my gaslog and draw your own conclusions.

-- Scott

[cems70]

Scott,

I looked at your gas log. I'd say you're about right... 5% - 6% improvement. Darn. I figured if I did the same CX/VX tranny swap into my DX hatchback with a 10% FE increase, it would take about 40,000 miles, with gas @ $3.00 per gallon and with the tranny swap costing around $300, to pay for itself. I'm pretty surprised the improvement is so small. The DX tranny revs like a blender next to my previous '95 VX.

Steve

[GasSavers_scostanz]

Steve,

$300 seems high, is that with someone else doing it? I did mine myself for about $100. I had hoped the FE increase would have been more myself. I still think it's worth it and it's a good starting point for further improvements. I look back through some of the historical data I have, a lot of it is not in my gaslog, and I'm seeing a pretty good improvement with just the few things I've done. I think I'm getting roughly about a %10 improvement with the CX tranny, 50# air pressure in my tires, a grill block and slowing from 70 mph to 65 mph on my route to work.

Another thing to consider is the type of driving you're doing. I use my car almost exclusively to go back and forth to work, a 133 mile round trip everyday almost all highway. I have no data for city driving but it could result in more than the 5% - 6% increase I'm seeing if that's the type of driving you do. Maybe someone else here who has done this swap and does mostly city driving could provide some insight for us.

By the way, what kind of mileage are you getting now?

-- Scott