fuel measurnments

williams · Post 13 May 2006, 06:11

hello

i am wondering how formula 1 fuel is measured (ie: kilograms or litres)

and why is it measured in the specific way.

bhall · Post 13 May 2006, 06:19

My guess is that it's measured in liters, as fuel suppliers are always looking to make lighter fuels. A volumetric measurement seems to be the only consistent way to measure.

manchild · Post 13 May 2006, 15:25

Kilograms - because weight to power ratio is crucial for performance. Comparing engine power with liters in tank gives you no info, but engine power vs overall weight of the car (including fuel) does. BHP/KG

joselu43 · Post 13 May 2006, 17:15

Weight. Volume changes with temperature, volume does not. This would lead to mistakes and inconsistencies.

Venom · Post 13 May 2006, 17:24

joselu43 wrote:Weight. Volume changes with temperature, volume does not. This would lead to mistakes and inconsistencies.

You mean weight does not?

I think this isn't true with diesel thou. Only petrol.

Sawtooth-spike · Post 13 May 2006, 19:11

Weight is Relitive, Volume is Consistant

vyselegend · Post 13 May 2006, 19:19

Sawtooth-spike wrote:Weight is Relitive, Volume is Consistant

Yes, unlike mass, weight is relative, at least that's what I've been taught in physics at school. And volume is relative in a flexible container, but in a static one, it only change pressure, as oviously the total volume is fixed.

Hope I didn't said something stupid, I was quite bad at physics at school

DaveKillens · Post 13 May 2006, 21:51

In all FIA regulations involving fuel, liters is always the unit of measurement. The fule composition is determined by percentages, though. Article 19.

manchild · Post 14 May 2006, 00:12

FIA yes but teams calculate fuel in kilograms not liters... most of all because 1 liter of fuel doesn't weight 1 kilogram.

SuperSonic · Post 14 May 2006, 00:36

Nice topic to ask.

- How does the FIA estimates the ammount of fuel burnt per lap for the purpose of refueling cars after qualifying?

- Where can I find those figures for each track? At least for the previous GP's.

f1.redbaron · Post 14 May 2006, 17:04

manchild wrote:FIA yes but teams calculate fuel in kilograms not liters... most of all because 1 liter of fuel doesn't weight 1 kilogram.

If I'm not mistaken, 1L of regular, everyday fuel is 0.75kg. What is it in F1?

Mikey_s · Post 15 May 2006, 10:25

Like the answer to most questions the real response is 'it depends'. From the scientific perspective the engine burns fuel to generate the energy to move the car; this is dominated by stochiometry ( efficient use of fuel). This is mass based as the chemistry requires x molecules of fuel (with a given molecular mass) with y molecules of oxygen. Therefore the fuel burn is mass governed. However, liquids are generally measured in volume and the fuel rig is calibrated to deliver a fixed volume of fuel in a given time period (12 litres/sec I seem to recall). The problem being that the density (mas per unit volume) changes with temperature.

From a practical perspective it makes no difference whether you use mass or volume as a measure provided you know the relationship between mass and volume over the temperature range you are working - certainly this will be known by all the teams as it will be given by the fuel supplier.

In the past the teams used to cool the fuel down as this gave a greater density (mass per unit volume), so more power could be put into the car - remember, the fuel tank will be a fixed volume. At hot venues this occasionally led to the fuel warming up and spilling out as it increased in volume - I remember seeing lots of thee teams putting reflective blankets over the cars to try and reduce the solar gain... don't seem to see that so much any more, probably because the cars are permitted to refuel, so the tanks are not filled brim full any more.

bhall - your comment about the fuel suppliers wanting to make lighter fuels is not fully correct - the majority of the fuel chemistry is governed by the FIA regulations. However, the small window the suppliers have to play with focuses them on putting more energy into the fuel for a given mass - that means more chemical bonds. But the density of the fuel is specified in the regs and must be between 720.0 - 775.0 kg/m^3 at 15°C.