Questions tagged [fuel-economy]

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Can turbine engines really run on “just about anything”?

I often read that turbine engines can run on almost any fuel source. I understand that turbine engines are less "picky" in terms of the fuel source that they can use, but surely there would still be ...
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0answers
18 views

PLEASE ANSWER Sterling vs Combustion Engine

This may be difficult to answer but, theoretically, if you had a car with a sterling engine that produces say approximately 300 horsepower how much of any specific heat source would need to be used if ...
2
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1answer
44 views

does payload weight distribution affect rolling resistance?

Recently came across the following 2-minute YouTube video that claims A Balanced Rig Saves Fuel While nicely done, it is a marketing video. Does anyone know of any unbiased studies that support the ...
2
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1answer
56 views

How much air will an engine use per tank of gas?

Apparently I have a stupid question. I got curious and crunched some numbers to determine approximately how much air an engine consumes in total to burn a full tank of gas. Something went horribly ...
5
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2answers
252 views

Whats the purpose of a main metering system in a carburetor?

I'm confused on how to differentiate mixture control from the main metering system, and why we even need one at all. Let's say we had a large resovior, and a needle type mixture control system. The ...
0
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1answer
108 views

Best fuel for supercar engines

To experienced supercar owners/engineers: What is the best fuel for a turbocharged 6 liter V8, 7.6 liter V10, or 9.2 liter V12 (Audi R8 or Lamborghini Aventador type cars) in terms of speed/...
4
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4answers
2k views

Why wont Petrol engine run on Acetylene?

Boiling temperature of Acetylene is -84°C and that of Petrol is 95°C (at Atmospheric Pressure). So the spark is efficient to ignite the compressed Acetylene and run the Engine. But why wont that work ?...
-2
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1answer
77 views

seperate engines working vs single engine [closed]

Assuming we have 2 identical cars. What is the total energy consumed by the two cars to start and accelerate up to a specific speed versus the total energy for one of them to accelerate up to a ...
15
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2answers
6k views

While going downhill, does my car consume less fuel when in neutral or in gear?

I once meditated on the fact that a car, in downhill, would consume more fuel when in neutral to keep the engine on, rather than in gear. To keep the engine on when in gear, in fact, you mostly need ...
4
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1answer
349 views

How does the optimal-gear indicator work?

Some modern cars, including models by BMW, Ford and Audi, have a system on the panel that tells the driver the next gear to use while driving, for optimal fuel economy. How does the vehicle decide ...
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9answers
4k views

How can “mpg” be high under low engine load?

Let's say a car at 60 mph requires roughly 20 hp to maintain its speed (i.e., to overcome rolling resistance and drag). If this car makes 240 hp and gets about 34 mpg (not too unrealistic), how is it ...