Typical mpg for e89 20i ‘13 plate??

[Pbondar]

The ‘issue’ with the N20 engined E89s is that with a very fat and flat torque curve compared to the N52 and predecessor engines where the torque curve has less peak torque and has much more of a peak and is delivered at relatively high rpm, it’s very easy to move ‘expeditiously’ without apparently ‘driving hard’

Ignoring transmission related losses, manuals being best, followed by 8HP autos then 6HP autos then slush boxes..the fuel consumption is related to the bhp generated per measure of fuel burnt.

The duality of earlier engines is that if you keep the revs low your progress is slower than an N20 due to less torque being available, conversely if you keep one of the earlier engines on the boil it’s operating at peak torque which also happens to be the best specific fuel consumption for bhp created.

So when you distill all that down the N20 is much more sensitive to the drivers approach.

If he consciously short shifts, either in manual or comfort mode if auto and uses modest throttle then it will be slightly more economical than the predecessors..if he just presses the pedal and makes good progress he will probably burn more fuel.

This is best illustrated on the 40 plus days over 4 years of going on Z4 runs...what I found when we came to top the tanks up time was that if I was ‘tail end charlie’ then my fuel consumption was equal too or better than the E85s, however if I was ‘run leader’ my fuel consumption was around 5 litres worse in 45 litres burnt..

[Jameszy]

The ‘issue’ with the N20 engined E89s is that with a very fat and flat torque curve compared to the N52 and predecessor engines where the torque curve has less peak torque and has much more of a peak and is delivered at relatively high rpm, it’s very easy to move ‘expeditiously’ without apparently ‘driving hard’

Ignoring transmission related losses, manuals being best, followed by 8HP autos then 6HP autos then slush boxes..the fuel consumption is related to the bhp generated per measure of fuel burnt.

The duality of earlier engines is that if you keep the revs low your progress is slower than an N20 due to less torque being available, conversely if you keep one of the earlier engines on the boil it’s operating at peak torque which also happens to be the best specific fuel consumption for bhp created.

So when you distill all that down the N20 is much more sensitive to the drivers approach.

If he consciously short shifts, either in manual or comfort mode if auto and uses modest throttle then it will be slightly more economical than the predecessors..if he just presses the pedal and makes good progress he will probably burn more fuel.

This is best illustrated on the 40 plus days over 4 years of going on Z4 runs...what I found when we came to top the tanks up time was that if I was ‘tail end charlie’ then my fuel consumption was equal too or better than the E85s, however if I was ‘run leader’ my fuel consumption was around 5 litres worse in 45 litres burnt..

Great summary