Honda VX VS CX

[saturnfan]

Have a question for the Honda guys. I did some research on 92-95 VX/CX. Is this correct- CX 70 HP, 3055 lb curb wieght 42/48 mpg, VX 92 HP, same weight 48/55 mpg? If so why does the VX have a better MPG rating with same body/ weight and have more HP? is the CX way too underpowered? Just curious?

[benstake]

The CX has 1.5L 8 valve Non-Vtec. The Vx has 1.5L 16 valve Vtec. The Dx has a lean burn mode on its engine too. Same body but completely different motor.

[saturnfan]

Ya, I see the DX has 102 HP, weighs a little more and a EPA rating of 35/40 mpg. My question is why does the VX (92HP) have a better EPA MPG than the CX (72HP)?

[theholycow]

I think it's the VTEC-E, wideband O2 based system, and tall gearing (made possible by the extra torque) that make the VX what it is compared to the CX. I imagine it was more expensive to purchase, and that O2 sensor alone makes it more expensive to maintain.

[IndyFetch]

The VX weighed 2,048 lbs, not 3,055. The CX is a little heavier than the VX, actually. The VX has some weight-reducing measures, such as an aluminum alternator bracket and alloy wheels, that the CX did not get. Also, the VX has aero mods such as a front spoiler, rear spoiler, and rear diffuser not included with the CX.

The CX had an old-style 8-valve engine, while the VX used a 16-valve engine with lean burn. At under 2400 RPM, the VX engine would run a 24:1 air-fuel ratio, whereas the CX would run 14.7:1, like other fuel-injected cars. The VX engine was also capable of closing one intake valve at low RPM during lean burn to allow for some swirl in the combustion chamber as well as to allow a light spray of fuel to collect near the plug just before firing in order to prevent detonation and "hot spots" caused by the lean burn condition. This also helped the car to pass emissions.

Speaking of emissions, the VX also had a catalyst mounted directly to the exhaust manifold. This heated up much more quickly than the catalyst mounted under the engine on the CX, which allowed the VX to switch to the closed loop system (and lean burn) more quickly. The CX and VX used the same transmission with the same gearing.

[Rusty94cx]

Not correct the cx and vx both have the cat right by the engine. I have 1 of each. They have the same trans and both have a smaller gas tank than the other hatches. 10 vs 12 or so yes the vx has alloy wheels that are light and also special brackets but the d15z1 is a little heaver. The simple answer is lean burn. My lean burn is not working and my cx and vx get just about the same mpg. And in no way does any eg hatch other than the vx have lean burn. The si has a v tech engine but it is also heavy and all about go fast. Short trans and gas guzzler. Yes the vx was pricey.

[theholycow]

Don't know how I forgot lean burn, that's the heart of the VX and it's what I was thinking of when I was on about the wideband O2. Glad you guys are on the job!

[saturnfan]

Sorry about my curb weight information. They must have weighed it while trying to break the world record for "how mand grown men will fit in a Honda hatchback" Did they only use lean burn in 92-95? Was it problematic? Why did they quit using it?

[Rusty94cx]

Yes on the eg 92 95 only on vx. The lean burn was then used on the ek 96-00 hx. Then then on the insight. It was hard if not impossible to meet emission standards. The Cali model didn't have lean burn. It was expensive. The 02 is list like 500$ from dealer. Good luck if you want one.....

[saturnfan]

So the biggest reason they didnt use it more was initial cost? The 48/55 MPG EPA is the best ive ever seen on a non-hybrid. What does the eg stand for? You said your lean burn isnt working, does your check engine light come on? What kind of codes do you get?