Fuel logic: Cooling System & Fuel values updated

Aircon: New standard, +1 when moving, +1 when stopped.
Fan: +1.1 when moving, +0.1 when stopped.

CheapPetrol: "Temperature increase" reduced to half
ExpensivePetrol: "Temperature increase" reduced to half
RacingPetrol: "Temperature increase" reduced to half

Engine overheating:
- New field length = 3/5 of the old one, so it goes from 5000 to 3000.
- Temperatures are half, so it goes from 3000 to 1500.
AbstractVan small fixes.