M40i fuel economy.

ori · Post by **ori** » Sat Jun 10, 2023 8:28 pm

I generally don’t check my mpg, but I was super impressed on my journey to Bristol and back.
Adaptive cruise set to 77mph and computer said I averaged 58.8 (road works means some chunks anrr 50mph) and got a whopping 48.2mpg.
When I filled up at the end of first leg, the computer said I had 503 mile range!

Yeah cruising on motorway is best and I was driving like miss daisy (speed cameras etc….) still impressive.

sars · Post by **sars** » Sat Jun 10, 2023 9:24 pm

The B58 is an amazing engine, I managed an average of 49.9 mpg over 215 miles on my way home from Bristol once

Argyll Andy · Post by **Argyll Andy** » Sat Jun 10, 2023 9:31 pm

Pondrew · Post by **Pondrew** » Sat Jun 10, 2023 10:19 pm

sars wrote: ↑Sat Jun 10, 2023 9:24 pm The B58 is an amazing engine, I managed an average of 49.9 mpg over 215 miles on my way home from Bristol once

Let's not get carried away here...
I could get 50mpg on a motorway journey with cruise set all the way in the 70s MPH in a B58 (360bhp 550nm tune), but everyday driving around town would see an average of low-mid 20s, which is expected IMO.
I can get 50mpg on a motorway journey with cruise set all the way in the 70s MPH in the B20 (270bhp 340nm tune), but everyday driving around town will see an average of mid-high 30s, which is far better.

Open the taps on the B58 for even brief periods and it will cost you fuel; simples.

ori · Post by **ori** » Sat Jun 10, 2023 11:16 pm

Pondrew wrote: ↑Sat Jun 10, 2023 10:19 pm
sars wrote: ↑Sat Jun 10, 2023 9:24 pm The B58 is an amazing engine, I managed an average of 49.9 mpg over 215 miles on my way home from Bristol once
Let's not get carried away here...
I could get 50mpg on a motorway journey with cruise set all the way in the 70s MPH in a B58 (360bhp 550nm tune), but everyday driving around town would see an average of low-mid 20s, which is expected IMO.
I can get 50mpg on a motorway journey with cruise set all the way in the 70s MPH in the B20 (270bhp 340nm tune), but everyday driving around town will see an average of mid-high 30s, which is far better.

Open the taps on the B58 for even brief periods and it will cost you fuel; simples.

We all know that opening the taps will drink the juice. What’s impressive is how the engine can cruise if needed.

JACKAZZ2000 · Post by **JACKAZZ2000** » Sun Jun 11, 2023 12:20 am

That is indeed impressive, howeverrrrrrr, I rarely use cruise control cause I like unleashing the BEAST.....

ori · Post by **ori** » Sun Jun 11, 2023 12:03 pm

JACKAZZ2000 wrote: ↑Sun Jun 11, 2023 12:20 am That is indeed impressive, howeverrrrrrr, I rarely use cruise control cause I like unleashing the BEAST.....

Love unleashing the beast….just not on motorway with a ton of average speed cameras.

JACKAZZ2000 · Post by **JACKAZZ2000** » Mon Jun 12, 2023 1:02 pm

No camera's where I live.

Nanu · Post by **Nanu** » Mon Jun 12, 2023 8:06 pm

Average speed cameras is where the cruise control really comes into it's own

PaperSniper · Post by **PaperSniper** » Sat Jul 22, 2023 12:55 pm

From the USA, I get 29 mpg or about 35 UK mpg. I rarely drive with the top up, rarely drive on highways. Always drive in Sport mode, and do my own shifting about 50% of the time. My driving is about 90% back roads, traveling at 50-60 mph, with the other 10% driving in town traffic. I'm quite impressed actually. I did not expect any better than about 25 USA mpgs.

Doug

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