scorched bores and efficient mode

[ajm55]

A mate has recently had 2 M engines replaced by BMW - one on his F10 M5 and the other on his X5M. Both were replaced because of damaged bores.

When asked about the likely cause of the damage, he speculated that driving the car predominantly in efficient mode over many years might be the culprit. When asked how so, he explained that in efficient mode (as opposed to SportPlus), certain cylinders shut off unless you go WOT - or so he was told by someone at BMW.

I'm curious to know whether (a) it is correct that when efficient mode is engaged, certain cylinders shut off, and, if so (b) whether that could result in damage to the bores.

With the new motors, he invariably engages SportPlus immediately after start-up.

Anyone know the answers?

[AnotherM]

Originally Posted by ajm55

A mate has recently had 2 M engines replaced by BMW - one on his F10 M5 and the other on his X5M. Both were replaced because of damaged bores.

When asked about the likely cause of the damage, he speculated that driving the car predominantly in efficient mode over many years might be the culprit. When asked how so, he explained that in efficient mode (as opposed to SportPlus), certain cylinders shut off unless you go WOT - or so he was told by someone at BMW.

I'm curious to know whether (a) it is correct that when efficient mode is engaged, certain cylinders shut off, and, if so (b) whether that could result in damage to the bores.

With the new motors, he invariably engages SportPlus immediately after start-up.

Anyone know the answers?

I have monitored live data on my 2016 in comfort mode and never seen a cyclinder "off"

[ajm55]

Originally Posted by AnotherM

I have monitored live data on my 2016 in comfort mode and never seen a cyclinder "off"

Thanks for the feedback. Yea, the theory seems unlikely but anything's possible

[vafan13]

I'd expect there to be a significant mpg improvement if Efficient could shut off cylinders on demand. I believe Efficient primarily does three things: higher coolant temp, smoothed out throttle response, and doesn't keep the turbos spooled as long.

Pretty sure the scorched cylinders are from karma, for having mostly driven these cars in Efficient, lol. Terrible luck, though

[ajm55]

Originally Posted by vafan13

I'd expect there to be a significant mpg improvement if Efficient could shut off cylinders on demand. I believe Efficient primarily does three things: higher coolant temp, smoothed out throttle response, and doesn't keep the turbos spooled as long.

Pretty sure the scorched cylinders are from karma, for having mostly driven these cars in Efficient, lol. Terrible luck, though

lol! I'm with you on the karma bit but not sure I'd describe his experiences as bad luck experiences. He now has a new motor (funded by BMW) in each vehicle