“Race Fuel” – Myth and Facts

Started on 27.09.2017

Mystic powers are often attributed to the fuel in the current Formula One. Although the regulations stipulate “petrol station gasoline Super Plus”, the permitted additives from the mineral companies are precisely tailored to the engines of their customers and thus have a significant upgrade in the performance of the Formula 1 engines.

The regulations allow only a maximum fuel quantity of 105 kg per race and a maximum flow rate of 100 kg per hour. This considerably limits the use of additives.

However, “free” fuel mixtures with a high proportion of alcohol, such as it is used on “quarter-mile” races or speedway and sand track races, can lead to considerable increases in performance. Ethanol and methanol are added to the gasoline with a proportion of up to 80%. The oxygen atoms bound in the molecules of the two alcohols cannot be released during combustion and thus do not act as a chemical compressor.

In contrast, nitromethane has free oxygen atoms that act as a chemical compressor. Nitromethane is only added in very small quantities (max. 15%), is very expensive, is subject to the laws of explosives liquids and leads to extreme loads on the engine components.

However, the advantages of the alcohols as fuel also have some disadvantages:

Advantages:

+ very high octane-rate (up to ROZ 160), which allows an extremely high compression ratio (up to 17: 1),

+ high evaporation heat (or actually “cold”) leads to a high internal cooling of supercharged engines,

+ Reduction of the thermal load on the motor components.

Disadvantage:

– low calorific value (only about 50% of gasoline) and thus significant additional consumption, which requires considerably larger injectors,

– the optimum mixing ratio drops down to a lambda of approx. 0.5,

– With high proportions alcohol and gasoline tends to “demix”.

SuperPlus: ROZ 103, calorific value 10.200, heat of evaporation approx. 80

Methanol: ROZ 160, calorific value 4.700, heat of evaporation 270

Ethanol: ROZ 150, calorific value 6.400, heat of evaporation 225