I've found some technical information about WRC. It seems modern cars are more efficient with fuel consumption, but my estimation of 1L per km was not so crazy, but quite close at least for old cars with gigantic engines. I will reduce the value to 0,7 L per km.
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"In the article is said that on a typical rally stage the fuel consumption for the Fiesta WRC is about 0,7 l/km.
On the Skoda’s web page (http://new.skoda-auto.com/en/motorsport/cars) the fuel consumption is 0,6 l/ SS km for the S2000.
The Fiesta consume 0,7 / 0,6 = 1,17 (17%) more fuel on a special stage.
With fuel consumption it doesn't make sense because turbo cars have anti-lag (pure waste of fuel). 70 l/100 km seems to be really low figure but maybe with direct injection it is possible. On the other hand there is no direct injection in Fabia S2000 so even without ALS it's not comparable. I'm no expert at all.
Now engines both in r5 or wrc, so with direct injection, are using much less fuel than previous rally turbo engines, like in 2.0l WRC cars or GpN cars.
for example fiesta s2000 was using some 70l/100km ss, and R5 uses around 60l/100km ss, but it also depends on stage characteristics, etc."
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"In the article is said that on a typical rally stage the fuel consumption for the Fiesta WRC is about 0,7 l/km.
On the Skoda’s web page (http://new.skoda-auto.com/en/motorsport/cars) the fuel consumption is 0,6 l/ SS km for the S2000.
The Fiesta consume 0,7 / 0,6 = 1,17 (17%) more fuel on a special stage.
With fuel consumption it doesn't make sense because turbo cars have anti-lag (pure waste of fuel). 70 l/100 km seems to be really low figure but maybe with direct injection it is possible. On the other hand there is no direct injection in Fabia S2000 so even without ALS it's not comparable. I'm no expert at all.
Now engines both in r5 or wrc, so with direct injection, are using much less fuel than previous rally turbo engines, like in 2.0l WRC cars or GpN cars.
for example fiesta s2000 was using some 70l/100km ss, and R5 uses around 60l/100km ss, but it also depends on stage characteristics, etc."