Formula 1 engine mapping - Your questions answered

There has been a lot of talk lately about engine mapping, what with the changes made for Valencia and for Silverstone.

In Valencia the FIA outlawed the changing of engine maps between qualifying and the race, while from Silverstone onwards teams will have to rework engine maps and throttles so that there is no more than 10% throttle opening blowing exhaust through the diffuser when the driver lifts of the throttle pedal.

We've all got very carried away with talk of engine maps, but one reader,

Gondokmg, from South Africa, pulled us up and asked us to explain. He posted these extremely good questions the other day. So I took them to our friends at Mercedes-Benz and they were happy enough to put forward an engineer to explain.

What is the difference between an engine map (like what the FIA have now prevented teams from changing between qualifying and the race) and an engine mode (like that Vettel had switched on just before he crashed into Webber in Turkey last year) ?

Mercedes: "There is no accepted universal definition of what constitutes a map or a mode, but we draw a general distinction between a 'mode' and 'mix' settings: what the question refers to as a 'map' we would refer to as a

'mode', and what the question calls a 'mode' we would call 'mix settings'.

Generally we accept that by “mode” we mean a broad description of a regime under which we run the engine. This defines the philosophy of ignition mapping, fuelling and the distribution of fuel cut strategies used to

achieve the torque that the driver demands. This is what the teams were no

longer allowed to change between qualifying and the race in Valencia.

Engine “mix” settings are detail changes to fuelling that are routinely

used during the race to reposition ourselves on the curve between fuel

consumption and engine power."

For a race like Valencia where the off-throttle EBD is still allowed,

what stops a team like Red Bull from replacing their extreme engine map

with an extreme engine mode (still part of the race engine map) for use in

qualifing and also in the race for brief periods (e.g. at the start to

create a gap, to overtake or to defend a position)?

Mercedes: "Crucially, because all teams now use a common engine management system, there are limitations as to what any team can change with the car on-track, and these are only the engine “mix” settings. Fundamental changes to engine “modes”, where teams may chose to put aggressive or fuel-inefficient strategies into their cars for qualifying, can no longer be made for the race with the car in the garage or by the driver on-track."