[brucepick]

Originally Posted by Cleft_Asunder

Your HX has the same gear ratio's as my 97 DX, therefore your FD is 3.7. Honda did something different with your engine but I don't know the details right now. Check the chart at the bottom for gear ratio comparisons:

crxMPG - Gas mileage never looked so good » Uncategorized

As for what else Honda did to the engine:
The HX has Lean Burn technology, which offers a lean fuel mix under certain favorable conditions and up to about 1/3 throttle. And, it uses variable valve timing (VTEC) but it's a different setup from what's used on the EX and Si versions. I'm not sure but I believe it kicks in at lower rpm's and is a less extreme change to valve operation than the EX / Si setup.

Hmmm. Sorry - I'm going just a bit off the original topic on this but what the heck.

Gearing:

(Edit)
My HX at 60 mph:
2350 using ScanGauge data
2400 using instrument gauges
(/Edit)

My '97 Civic owner's manual doesn't give gear ratios but it does give top speeds for each gear, up to a max of 118 mph. I'm assuming the speed stated is at the red line max, which I'm also assuming is the same for all models covered (rpm's computer-limited by intermittent fuel cut).

For 3rd gear, which is the highest gear where it offers a comparison of all models it mentions, here's the data:
DX: 92 mph
EX: 82 mph
HX: 100 mph

for 4th gear:
DX: 118 mph
EX: 113 mph
HX" "Top Speed" is what it states. Apparently more than 113 mph.

So if red line is the same for all and top speed is limited by max rpms, then the gearing for each of these models is different. Sorry, the CX and LX aren't mentioned in my manual.