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Old 11-28-2007, 02:37 PM   #3 (permalink)
MetroMPG
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Join Date: Nov 2007
Location: 1000 Islands, Ontario, Canada
Posts: 22,514

Blackfly - '98 Geo Metro
Team Metro
Last 3: 70.09 mpg (US)

MPGiata - '90 Mazda Miata
90 day: 52.71 mpg (US)

Even Fancier Metro - '14 Mitsubishi Mirage top spec
90 day: 70.75 mpg (US)

Appliance car - '14 Mitsubishi Mirage ES (base)
90 day: 52.48 mpg (US)
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Dan chimes in with some critical VX info:

Quote:
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 a 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.
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Project MPGiata! Mods for getting 50+ MPG from a 1990 Miata
Honda mods: Ecomodding my $800 Honda Fit 5-speed beater
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Ecodriving test: Manual vs. automatic transmission MPG showdown



EcoModder
has launched a forum for the efficient new Mitsubishi Mirage
www.MetroMPG.com - fuel efficiency info for Geo Metro owners
www.ForkenSwift.com - electric car conversion on a beer budget
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