Why the Civic VX is a superior highway FE machine

MetroMPG · 10-28-2006, 05:23 PM

This thread was split off from the Daily FE Update thread, because it's got some good VX info in it.

It originally started with Dan (krousdb) saying...

Quote:

Originally Posted by krousdb

Now, if there were a high speed FE ranking, the VX would be hard to beat. Even without drafting, I can maintain leanburn at 75 MPH.

MetroMPG · 10-28-2006, 06:42 PM

I'm mainly talking about highway FE performance.

basjoos · 10-29-2006, 02:47 AM

If I swapped a VX engine into my car, I wonder to how high a speed I could maintain lean burn and how much it would improve my overall mileage.?

krousdb · 10-29-2006, 05:55 AM

Quote:

Originally Posted by basjoos

If I swapped a VX engine into my car, I wonder to how high a speed I could maintain lean burn and how much it would improve my overall mileage.?

http://72.14.209.104/search?q=cache:...&ct=clnk&cd=11

A good read on the VX. This compares the 92 VX to the 91 DX, although there are some references to the 92 CX. The interesting stuff begins on page 22.

To answer your question,

Table 4: Technologies Used to Increase Fuel Economy in 1992 VX
Fuel EconomyImprovement (%) '91 DX to '92 VX

Multi-point fuel injection 1.5%
Low rolling resistance tires 1%
variable valve timing 2.5%
lean burn 5 -10%
reduced friction 1.5%
roller cam followers 1%
Weight reduction 2.5
Aerodynamic improvements 1.5%
Gearing and drive ratio changes 2%
Reduced idle speed/rpm 3%
Shift indicator light 5%

Total 45.5% - 50.5%

When comparing to your CX, I would guess that only the VVT, lean burn, reduced friction and roller cam followers would apply. That adds up to 10-15%. Somehow I have a difficult time believing that.

Perhaps iyou could to put your aero mods on my car to test it out before taking the plunge with a swap.