AE31 - cylinder(bank) deactivation

[andy_mc]

I wondered if anybody knew the rules around the cylinder/bank deactivation on this V12/DB11 engine?

For example, when you first start the engine - do both banks light up, at idle?

Is it linked to engine load/throttle position and/or driving modes?

[pschlute]

andy_mc said:

I wondered if anybody knew the rules around the cylinder/bank deactivation on this V12/DB11 engine?

For example, when you first start the engine - do both banks light up, at idle?

Is it linked to engine load/throttle position and/or driving modes?

It runs as a 12 cylinder engine all the time, unless a constant-ish speed is maintained for a period ....eg motorway driving.

Then it switches from left to right bank and so on. You never notice it is happening unless you look at the consumption indicator.

[Calinours]

As outlined above it starts and runs as a V12, only alternately turning off fuelling on each bank at light constant load when warm (on motorway).

Such systems have to regularly alternate the sides of each bank to keep catalysts and other components on each side at operating temperature - when ambling along at say 75 in I6 mode, whichever bank is unfuelled and inactive needs to always be ready to respond to driver demand for instant full V12 power.

[skhannes]

It might be worth noting that cylinder deactivation is disabled when in either sport or sport+ mode. Start/stop is also deactivated in sport + mode although it can be shut off from a dash button on each startup.