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Gas: US vs Europe

hevansrv7a

Well Known Member
According to Wikipedia, Mogas in Europe weighs 6.3 pounds per US gallon. Most sources put the weight of gas in the US at less than 6.1 pounds per gallon.

The energy content is different in a gallon, US vs Euro. In other words, energy per volume of the fuel is different there than here.

Does the Rotax 912 ULS (for example) sold here or there have different jets or other differences in its carburetion?

The energy per volume and weight per volume of E10 Mogas is also different than for unadulterated Mogas.

If not, what are the effects of that difference on published engine performance?

Please, let's confine this to those who actually know rather than guessing, supposition, etc.

Thanks.
 
Interesting question that my hangar-mate and I just had this weekend. I have been using 6 pounds per gallon for fuel weight on weight and balance calculations and he said that unleaded is 6.3 pounds per gallon. So we used a certified scale on the actual fuel I use which is 94 octane/Zero ethanol Unleaded Gasoline.

One gallon of 94/Zero-UL was 6.089382 pounds per gallon.
 
Interesting question that my hangar-mate and I just had this weekend. I have been using 6 pounds per gallon for fuel weight on weight and balance calculations and he said that unleaded is 6.3 pounds per gallon. So we used a certified scale on the actual fuel I use which is 94 octane/Zero ethanol Unleaded Gasoline.

One gallon of 94/Zero-UL was 6.089382 pounds per gallon.
👍 Thanks. Facts are always helpful.
 
Interesting question that my hangar-mate and I just had this weekend. I have been using 6 pounds per gallon for fuel weight on weight and balance calculations and he said that unleaded is 6.3 pounds per gallon. So we used a certified scale on the actual fuel I use which is 94 octane/Zero ethanol Unleaded Gasoline.

One gallon of 94/Zero-UL was 6.089382 pounds per gallon.

What was the temperature when you weighed the fuel?
Fuel density changes quite a bit depending on temperature. This is very apparent if you top off your tanks and then leave it out in the sun. Fuel may pee out the fuel vent. You still have the same pounds of fuel but the increase temp increased your gallons.
 
Don't forget that a US gallon is smaller than the rest of the world's gallons. A US gallon is a shade under 4 litres, the rest of us use 4.55 litres to a gallon. Maybe that's where the discrepancy comes in.
Just a thought.
Cheers DaveH
 
Don't forget that a US gallon is smaller than the rest of the world's gallons. A US gallon is a shade under 4 litres, the rest of us use 4.55 litres to a gallon. Maybe that's where the discrepancy comes in.
Just a thought.
Cheers DaveH

US Gallon = 3.7854 liter or 231 cubic inches
Imperial Gallon = 4.54609 liters or 277.42 cubic inches

Above info found here.

Ethanol that is used in gasoline in the US has 77,000 BTU per US Gallon.
Gasoline has 124,884.378 BTU per US Gallon.

Someone already listed the weight of a gallon of ethanol free MoGas at an unknown temperature so I will not look up a different number as that is close enough for me.

Ethanol is 6.58 pounds per US Gallon at 68-degrees F.
 
What was the temperature when you weighed the fuel?

We did not measure temperature of the fuel. The fuel used was siphoned from a 10.5 gallon Flo-Fast that had been sitting in the uninsulated hangar overnight. The overnight temperatures had gone down to 61 degrees and we did this around 9am when outside air temperatures had risen into the low 70s. Given the mass of ten plus gallons the temperature of the gasoline had probably not risen much above the low to mid 60s in that short of time.
 
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