Tests for fuel consumption
Tests for fuel consumption
(OP)
Is there anyone that has done tests for fuel consumption at vairous speeds in a variety of automobiles and engines?
I am especially interested in case where the results are counter to what is expected. Meaning improved economy at higher speeds than at lower speeds.
I would like to see some figures on various vehicles HP requirements at various speeds, not calculated but actual measured.
I am especially interested in case where the results are counter to what is expected. Meaning improved economy at higher speeds than at lower speeds.
I would like to see some figures on various vehicles HP requirements at various speeds, not calculated but actual measured.





RE: Tests for fuel consumption
However when it comes to race cars...I have done several test sessions to determine fuel mileage in several SCCA and IMSA race cars over the years. Three that I have posted in these forums before come to mind mostly because if you plot them you will find that the graph is linear...for what that is worth. Thanks to Robert R. for that little tid bit.
1963 Mini Cooper 1380cc, ~136hp, 7 gal/hr.
1966 Lotus Cortins 1594cc DOHC, ~185hp, 9 gal/hr.
Tube frame Pantara (IMSA GT)5000cc, ~500hp, 24gal/hr.
Lotus and Pantara were tested at RIR in the early 80's.
Mini was tested at Willow Springs in June, 2004.
Rod
RE: Tests for fuel consumption
Cheers
Greg Locock
SIG:Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips.
RE: Tests for fuel consumption
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Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips Fora.
RE: Tests for fuel consumption
Regards
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Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips Fora.
RE: Tests for fuel consumption
No, I'm pretty sure al the cars would be in top by 30 mph.
Cheers
Greg Locock
SIG:Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips.
RE: Tests for fuel consumption
economy goes down. Pick-up trucks for obvious aerodynamic reasons start going down hill a long time before a prius would. The point at which a vehicle starts to lose out depends on its design. How high its mileage can get to start with depends on the engine, transmission, gearing, etc. See
www.el
as a good reference with a graph.
RE: Tests for fuel consumption
As the gear ratio and speed got higher, I would expect the aero to overtake BSFC as the dominant factor.
I would expect great variations from model to mode, depending on variations in rolling resistance, aero resistance, gear ratios and BSFC sweet spots at the required throttle opening to maintain steady state speed, but I would have expected to see optimum MPG at a lower speed and I would expect to see smooth curves on the graph.
Some of those lines look more like a saw blade across an area that represents one gear only. Not at all what I would expect from a car with EFI. Surely the BSFC does not jump around that much.
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RE: Tests for fuel consumption
http:
RE: Tests for fuel consumption
None the less several cars do have a couple of peak efficinecy speeds.
Cheers
Greg Locock
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RE: Tests for fuel consumption
So notice how the 97 Celica gets better MPH at 65 than at 55. And best is at 60, kinda blows some holes in some popular ideas about fuel economy. Thanks again.
RE: Tests for fuel consumption
- Steve
RE: Tests for fuel consumption
Mike McCann
MMC Engineering
RE: Tests for fuel consumption
My dad's VW DSG (6-speed automated-manual with no torque converter) is in 4th at 30 mph / 50 km/h constant speed cruise. At constant speed cruise, it's not in 6th until around 70 km/h. I would expect a couple of peaks and valleys in the consumption curve in that speed range.
RE: Tests for fuel consumption
...I was hoping GM would reply with something like: "...55 mph on straight and level roadway..." or something similar, but after a LONG wait, I instead got the terse non-answer: "...depends on your vehicle, weight and driving habits."
...one would "think" the GM engineers would have an "a prioria" design goal for such a major performance criteria...apparently not?!?
RE: Tests for fuel consumption
RE: Tests for fuel consumption
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