My Pontiac Firefly / Chevrolet Metro / Geo Metro / Suzuki Swift welcomes fuel efficiency nerds everywhere

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Latest fuel economy stats
for my '98 Firefly 1.0L 5-speed
  best: 2.3 125.1 104.2
 worst: 6.4  44.1  36.8
prev.3: 3.3  82.3  68.6
   all: 3.8  73.4  61.1
L/100km | mpg IMP | mpg US
Jul 28/07: more, graph, calc.
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Best non-hybrid MPG: Mitsubishi Mirage
Highest MPG for a new car: Mitsubishi Mirage?
Mitsubishi's 1.2L, 3-cylinder Mirage is the first new non-hybrid car that can match an old Metro's mileage. The company says 44 mpg (US) highway, 37 city. (Some drivers are already beating that in various economy driving contests.) How? An efficient engine, very light weight and aerodynamic design.

Cheapest to own? 2015 Nissan Micra Forum
2015 Nissan Micra Forum
The Micra's fuel economy isn't its most notable feature -- the $10,000 price is. That makes it one of the cheapest cars to own. And its 109hp, 1.6L engine and good power-to-weight ratio means it's fun to drive too.

Latest 10 posts:
1. Recipe for getting 99.7 mpg from a Geo Metro
2. - famous aerodynamic Honda Civic gets a web site
3. Snapshot: effect of tire pressure on rolling resistance
4. 65+ vehicle modifications for better MPG
5. Metro mania: forget stocks, put your money in old Geos!
6. 100+ Hypermiling / ecodriving tips for better gas mileage
7. Experiment: how long should a block heater be plugged in?
8. Everything old is new again: Car and Driver magazine modifies an econobox to improve MPG
9. Project Convertible XFi: alfresco efficiency
10. The floor is yours: MetroMPG opens a fuel efficiency forum
11 ... 64. Show all posts

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Good MPG forums: I spend a lot of time at and have also been known to lurk around

Chevrolet Aveo forum - discussion of the Chevrolet Aveo and its siblings (Pontiac Wave, Pontiac G3, Suzuki Swift+, Daewoo Kalos).

> Lots more Metro links...
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Send me a note:
darin AT metrompg D-O-T com,
or here

MetroMPG has opened a fuel economy forum
Read about the project here, or go straight to
ScanGauge fuel economy computer Save fuel with a ScanGauge II fuel economy computer.
I personally recommend this tool. I've owned both versions (I and II) and can't say enough good things about it. If you're serious about saving fuel, get one.

For more information and to order, visit EcoModder.

Recipe for getting 99.7 mpg from a Geo Metro

Posted Wednesday, May 13/09 in Mods & Tests

Green Grand Prix logo

At the start of this month, alt-fuel and efficiency enthusiasts gathered in Watkins Glen, New York for the 5th annual Green Grand Prix expo and fuel economy rally. I entered my modified 1998 Pontiac Firefly (Geo Metro) in the rally, and managed to score the top result of 99.7 mpg (US) (2.4 L/100 km / 119.7 mpg imperial) in a field of 25 vehicles - including hybrids, diesels ... and even a pair of Vespa scooters! How does one squeeze 99 mpg from an old Metro? Here's the recipe - mods & driving techniques - used for the event...

The route ...

fuel economy rally route

The competition covered a 79 mile / 127 km circuit around Seneca Lake in New York's scenic Finger Lakes region. Drivers had 2 hours and 5 minutes to complete the course, consisting of both urban & rolling rural roads, where speed limits varied between 35 to 55 mph. According to organizers, the time limit was based on driving no less than 10% below the posted speed limits, and included a mandatory 10 minute rest stop in the city of Geneva.

The weather was ideal: sunny & mild, and only light & variable winds. (So variable that I actually noticed tail winds in both directions!)

The mods (in no particular order)...


Metro Kammback good for approximately 5% fuel economy improvement @ 55 mph.




  • ScanGauge, monitoring: instant MPG; tank MPG; average speed (time limit); open/closed loop; voltage (after switching off the alternator); elapsed time (watch)

The driving techniques...

  • Pushing the car (part way) to the start; at the mandatory rest stop in Geneva; in the gas station for the post-competition fill

  • Pulse & glide on the highway portion of the route, monitoring the ScanGauge to keep engine in closed loop during pulses

  • Light timing & traffic timing in urban areas to avoid stops & minimize slowdowns ("driving without brakes")

  • Moving to the extreme right of my highway lane ("ridge riding") or part way onto the paved shoulder to facilitate/encourage passing by faster traffic (there wasn't a lot).

  • and more than a few other from our 100+ eco-driving / hypermiling tips

The dispute ...

Fuel pump
There was some discussion about the accuracy of the refuelling method. (photo:

There was some debate after the event about the accuracy of the fueling method - and therefore the accuracy of the fuel consumption figures.

Prior to the start, drivers topped up their tanks at a gas station in Watkins Glen under the watchful eyes of rally scrutineers, who sealed all fuel caps with tape and a dab of silicone.

Competitors were instructed to stop filling at the first "click" off of the fuel pump. When the rally finished (at the same gas station, under the same scrutineers' watchful eyes), competitors again used the "first click" method to re-fill their tanks and thus measure fuel consumed.

Ideally, a driver would want to actually see the fuel level in the filler neck to ensure accuracy (particularly with such small fills). But filling to the brim can be a potential problem for vehicles with evaporative emissions systems, which draw vapour from the top of the filler neck. Filling to the top of the neck could cause liquid fuel to enter the evaporative system, potentially causing malfunction or even damage. Thus the decision by organizers to use the "first click" method.

Ironically, the more efficient the vehicle - the smaller the amount of fuel used - the larger the potential margin of error in the the "first click" method.

So, the important question: was the 99.7 mpg result accurate? Short answer: because of the filling technique, it's impossible to say for sure.

But it's definitely not outside the realm of possibility.

I've regularly exceeded 100 mpg (US) for round trips under ideal conditions. And last summer I drove for a tank achieving 104 mpg (US). Considering all the stops were pulled out at the Green Grand Prix, 99.7 isn't that much of a stretch.

Other class-leading competitors...

EM participants
Four EcoModder vehicles participated in the 2009 Green Grand Prix, taking 3 awards.

Several other EcoModder members also competed in the Green Grand Prix, turning in some impressive numbers:

  • Tim Sullivan (McTimson), using driving technique alone (and MPG instrumentation), got 53.1 / mpg (US) (4.4 L/100 km / 63.8 mpg imp.) from his unmodified 1993 Toyota Tercel

Congrats, guys!

Resources ...

EcoModder fuel economy forum Note: MetroMPG has opened a fuel economy forum
Read about the project here, or go straight to

darin AT metrompg D-O-T com, or here