Official 2019 Abu Dhabi Grand Prix Thread ***SPOILERS***
Discussion
Just had an Instagram advert from Shell, including a question for Charles on extra fuel weight. 
https://youtu.be/tSqYuGVCO8I
https://youtu.be/tSqYuGVCO8I
37chevy said:
Exige77 said:
I believe there’s a temperature range when the weight should be taken.
It’s really splitting hairs anyway as it won’t materially effect anything.
not really, ive been over/ under weight in a kart race before because temperatures have risen/ decreased from the time I measured/ poured fuel into the tank to the point the kart has been weighed. It’s really splitting hairs anyway as it won’t materially effect anything.
The point of using mass is that it isn't temperature dependent as before teams were chilling fuel to get more per *litre* - it's why they say its best to fill a car early in the morning as you get more fuel (a higher density) per litre.
By measuring in KG there's no wiggle room, at - 40 C it may be 0.9l and at +40 C it could be 1.1 litres, however it'll still weigh 1 kg.
37chevy said:
Exige77 said:
I believe there’s a temperature range when the weight should be taken.
It’s really splitting hairs anyway as it won’t materially effect anything.
not really, ive been over/ under weight in a kart race before because temperatures have risen/ decreased from the time I measured/ poured fuel into the tank to the point the kart has been weighed. It’s really splitting hairs anyway as it won’t materially effect anything.
The weight (strictly speaking we should use mass not weight) does not alter with temperature, IIRC the controls on fuel temperatures are there purely since having colder fuel can have performance benefits, it has nothing to do with the amount of fuel you can get in the car.
RemarkLima said:
37chevy said:
Exige77 said:
I believe there’s a temperature range when the weight should be taken.
It’s really splitting hairs anyway as it won’t materially effect anything.
not really, ive been over/ under weight in a kart race before because temperatures have risen/ decreased from the time I measured/ poured fuel into the tank to the point the kart has been weighed. It’s really splitting hairs anyway as it won’t materially effect anything.
The point of using mass is that it isn't temperature dependent as before teams were chilling fuel to get more per *litre* - it's why they say its best to fill a car early in the morning as you get more fuel (a higher density) per litre.
By measuring in KG there's no wiggle room, at - 40 C it may be 0.9l and at +40 C it could be 1.1 litres, however it'll still weigh 1 kg.
Just using a quick online calculator on 100kg fuel the difference between its weight is 1kg for every 10C temperature variance....so it’s more than you’d think
Edited by 37chevy on Tuesday 3rd December 13:48
Cabinet Enforcer said:
Only if you measured it in by volume, and even if you did so then you are looking at about 200g for a kart tank(about 3%) for a temperature difference of 30degC. F1 teams do not measure by volume, this is not the issue.
The weight (strictly speaking we should use mass not weight) does not alter with temperature, IIRC the controls on fuel temperatures are there purely since having colder fuel can have performance benefits, it has nothing to do with the amount of fuel you can get in the car.
As stated previously, I measured by kg...this varies with temperature as does density...The weight (strictly speaking we should use mass not weight) does not alter with temperature, IIRC the controls on fuel temperatures are there purely since having colder fuel can have performance benefits, it has nothing to do with the amount of fuel you can get in the car.
37chevy said:
Exige77 said:
I believe there’s a temperature range when the weight should be taken.
It’s really splitting hairs anyway as it won’t materially effect anything.
not really, ive been over/ under weight in a kart race before because temperatures have risen/ decreased from the time I measured/ poured fuel into the tank to the point the kart has been weighed. It’s really splitting hairs anyway as it won’t materially effect anything.
The kart, driver and his gear are weighed together.
You always leave a bit extra in the tank.
But anyway, we are talking about F1 and not karting.
Cabinet Enforcer said:
37chevy said:
As stated previously, I measured by kg...this varies with temperature as does density...
Weight won’t change with temp
Maybe the calibration of scales varies with temperature, but your kart didn't.
Otherwise, Albert Einstein would appreciate a call...
The Moose said:
This discussion has lead me to wonder a real-world question. Does that mean the cost of gas at the pump should fluctuate based on the ambient temperature at which it is dispensed?
No, it’s sold by the litre. A litre is a litre.
Your car’s performance may vary with ambient temps but we are getting away from the red team either cheating or being incompetent.
Exige77 said:
The Moose said:
This discussion has lead me to wonder a real-world question. Does that mean the cost of gas at the pump should fluctuate based on the ambient temperature at which it is dispensed?
No, it’s sold by the litre. A litre is a litre.
Say you bought 5 litres with at 0 degrees C, and I bought 5 litres at 40 degrees C. We’d both pay the same amount of money as the pump measures in litres and not kg.
The ambient temperature than becomes 20 degrees. You now have slightly more than 5 litres and I’d have slightly less than 5 litres. We’ve paid the same but now got different amount of fuel.
Of course in reality, the difference is so small it certainly wouldn’t be worth the effort and confusion of trying to take it into account.
Paul_M3 said:
Exige77 said:
The Moose said:
This discussion has lead me to wonder a real-world question. Does that mean the cost of gas at the pump should fluctuate based on the ambient temperature at which it is dispensed?
No, it’s sold by the litre. A litre is a litre.
Say you bought 5 litres with at 0 degrees C, and I bought 5 litres at 40 degrees C. We’d both pay the same amount of money as the pump measures in litres and not kg.
The ambient temperature than becomes 20 degrees. You now have slightly more than 5 litres and I’d have slightly less than 5 litres. We’ve paid the same but now got different amount of fuel.
Of course in reality, the difference is so small it certainly wouldn’t be worth the effort and confusion of trying to take it into account.
Paul_M3 said:
Well in theory it should change price depending on the temperature it’s dispensed at. Yes, it’s sold by the litre, but at lower temperatures there is more energy contained within that litre.
Say you bought 5 litres with at 0 degrees C, and I bought 5 litres at 40 degrees C. We’d both pay the same amount of money as the pump measures in litres and not kg.
The ambient temperature than becomes 20 degrees. You now have slightly more than 5 litres and I’d have slightly less than 5 litres. We’ve paid the same but now got different amount of fuel.
Of course in reality, the difference is so small it certainly wouldn’t be worth the effort and confusion of trying to take it into account.
Say you bought 5 litres with at 0 degrees C, and I bought 5 litres at 40 degrees C. We’d both pay the same amount of money as the pump measures in litres and not kg.
The ambient temperature than becomes 20 degrees. You now have slightly more than 5 litres and I’d have slightly less than 5 litres. We’ve paid the same but now got different amount of fuel.
Of course in reality, the difference is so small it certainly wouldn’t be worth the effort and confusion of trying to take it into account.
perhaps not in motoring (besides the smug satisfaction on filling up on a cold morning instead of later in the day and knowing you've maximised your value) but there's enough of a difference to make it worth both cooling the fuel in a special chilled rig, and risk cheating on the minimum mandated temp to F1 teams (back when they had in race refueling)
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