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Old 08-26-2009, 09:33 AM   #1 (permalink)
MetroMPG
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Join Date: Nov 2007
Location: 1000 Islands, Ontario, Canada
Posts: 21,057

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

MPGiata - '90 Mazda Miata
90 day: 54.01 mpg (US)

Winter beater Metro - '00 Chevrolet Metro
90 day: 73.57 mpg (US)
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Tested: speed vs. MPG, 2008 Corvette Z06 (505 hp)



One of the guys I sail against regularly in our local sailing races (24 foot Shark fleet) has a 2008 Corvette Z06 with the 6-speed manual transmission.

After last night's race (we won! ), I brought up the subject of fuel economy, and he gave me his version of the occasionally heard story that Corvettes get surprisingly good fuel economy - given their power - when driven reasonably.

We know that the car's "secret" is its massive torque paired with very tall gearing and relatively good aerodynamics (Cd of 0.28, CdA of 6.27 for a '92 Vette - source), which allow it to loaf down the blacktop in top gear even at fairly low speeds. Sometimes they even win mileage competitions: http://ecomodder.com/forum/showthrea...thon-5508.html

Just for kicks, we're going to go out and get data to do a "speed vs. MPG" graph in the next few days.

Watch this thread!

[EDIT, Sept 11: added EPA ratings...]

For reference, the car's EPA fuel economy ratings are: 15 mpg (US) city / 24 mpg (US) highway / 18 mpg (US) combined

Source: Model 1 Vehicle Characteristics

[EDIT, August 28: added graph below, plus methodology ...]



Weather conditions:

August 27, 2009
Sunny, 18C
Wind E 7 km/h
Pressure 102.2 kpa
Humidity 48%

Raw numbers:
Speed km/h ... E (mpg US) ... W (mpg US) ... Avg mpg

50 ... 28.4 ... 29.0 ... 28.7
60 ... 35.9 ... 37.0 ... 36.5
70 ... 35.6 ... 35.6 ... 35.6
80 ... 33.4 ... 33.4 ... 33.4
90 ... 31.8 ... 32.1 ... 32.0
100 ... 30.6 ... 29.3 ... 30.0
110 ... 28.1 ... 27.5 ... 27.8
120 ... 25.9 ... 25.6 ... 25.8
Methodology:
Air conditioning was off, windows were up, and fresh air was on fan setting 2.

Speed was set once per pair of bi-directional runs with cruise control, cancelled with the brake between runs. Car was brought up to speed & leveled off before passing a "start" marker (road sign) where the ScanGauge was reset. (Note: other than entering engine size, ScanGauge was not calibrated to this car, speed & fuel use offsets were left at zero). Reading was taken after passing a "finish" marker and cruise was cancelled.
Route:
2 lane highway, straight, dry & level (follows river edge). The road runs SSW/NNE and can be found here: 1000 Islands Parkway - Google Maps
Traffic conditions:
There was rarely traffic ahead in my lane, and no closer than 5 seconds when present. Some traffic was present in the oncoming lane.
---

See also:

__________________
Latest mods test: 15 mods = 15% MPG improvement: A-B test, 2007 Honda Civic 1.8L, 5-speed
Ecodriving test:
Manual vs. automatic transmission MPG showdown: Nissan Micra 1.6L



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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