I was reading a PDF that was discussing the fuel economy improvements of the Civic VX over other models and one thing that piqued my interest was that it had a different axle ratio. Is this true? I know the transmission is different but I hadn't considered that the axle ratio would be different. Can anyone confirm this?

 

bump

 

the trans is different and just has longer gears

 

Axle ratio? That's odd terminology.

As far as actual axles goes there is zero difference between CX/VX axles and the DX/LX/Si axles.

I think they're trying to refer to final drive ratio, which is basically the ring and pinion gearing inside the transmission itself, which basically means you are talking about the entire transmission itself.

The CX and VX have a a super tall 3.25FD ratio, while the DX has a shorter 4.06, and the Si/Ex has the shortest 4.25FD ratio. The CX and VX also have the tallest gears themselves, which multiplied against the tall-*** FD ratio makes them super long legged trannies.

Just something to ponder when it comes to mpg and tall trannies:

There is a point at which the engine is at it's most efficient in terms of rpm, and it's not always the lowest rpm possible. I read an article literally 8 or so years ago that used a D15B7 92-95 Civic DX/LX engine as an example and it actually consumed less fuel at 3500rpm than it did at 2500rpm - this was an engine test not including the car itself, drag, etc.

At some point the rpm could actually be too low IMO so that you'll have to downshift or floor it to try and lug one of these smaller SOHC engines uphill. I know honda gave it's fuel sippers these tall trannies, but they're probably most effective in the 80-85mph range.

I can't stand driving a car with one of these trannies as I tend to want to leave the car in third gear for around town driving because it's painful trying to lug a D15 engine up hill with such tall gearing.

This is of course my opinion.

 

So if I had a transmission from a DX/LX '92-'95 civic and I wanted to have the same type of gear ratios as that from a CX/VX, would it make sense to take out the transmission and get a final drive gear that matched that of a CX/VX and put it into the DX/LX transmission? How difficult would it be to have a machine shop make a final drive gear that matched that of a CX/VX transmission? Or can I buy that part online separately, for less than simply buying a CX/VX transmission as replacement to a DX/LX transmission?

Also you says it's bad for uphills, well I live on a hill with a 23% grade and I was wondering how bad would it be to have one of these transmissions in this situation? I have a Land Cruiser that HAS to be in 1st gear in order to get up our hill and I've seen a Civic HF up where I live before. So I'm just wondering if you're just exaggerating the issues with this transmission or not.


Modified by imzjustplayin at 8:22 AM 10/27/2008

 

First of all IMO it's pointless to take two D trannies apart and swap in the FD from one into another.

CX and VX trannies are literally boat anchors to 99% of the Honda community, so they would be cheaper to buy used than trying to have anyone fab up a 3.25FD set. I'd bet that they'd cost somewhere around FREEfifty or so.

Seriously though what year/make/model is your car now?

Also the fuel economy improvements on the VX model have to do with the engine too, and the super light weight, the rear diffuser, chin spolier, etc. etc. It was a complete package. IMO swapping in one of it's ingredients will gain marginal, if any, mpg gains.

If you live in a hilly area I'd stay away from a VX/CX tranny. What's the point of having the super tallest gearing if you have to leave it two gears lower just to get around town?

 

i used to have a vx tranny on my d15z1 (go figure huh) I could almost bet you $1 that i can accelerate 1st through 2nd in my d15b w/ex tranny by the time you could get through first gear with the vx tranny. Also i can go up hills in 4th gear at like 2k that are atleast a 25% grade.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 95vxtealhatch &raquo;</TD></TR><TR><TD CLASS="quote">i used to have a vx tranny on my d15z1 (go figure huh) I could almost bet you $1 that i can accelerate 1st through 2nd in my d15b w/ex tranny by the time you could get through first gear with the vx tranny. Also i can go up hills in 4th gear at like 2k that are atleast a 25% grade.</TD></TR></TABLE>

Oh, I guess you just really like close, short gear ratios then.. You want a car that accelerates quickly, is "speedy" etc. etc. So with that in mind, do you consider a stock LX sedan painful by any measure?