Vehicle Preparation separates Unlock Tuning and component durability upgrades from Engine Mapping progression. Unlock Tuning gives access to the car’s tuning options; component durability upgrades relate to the durability of individual systems.
Engine Mapping levels are developed through research requirements based on driving distance and are distinct from the non-engine upgrades listed in the catalogue. Research Knowledge helps reduce the requirements for completing engine-upgrade research.
The maximum number of Engine Mapping levels depends on the vehicle. The garage includes cars with four, five and six levels. The upgrade catalogue provides the per-model count where available.
You can use the Car Upgrade Guide in Chapter 13 to compare available upgrades and their costs.