Hi All,
23i - 2009 - 81500 miles
Just finished a 330.8 mile topless drive (roof down, not shirtless). Hull to Plymouth, four rain showers, one very heavy but I stayed dry. Just finished picking the flies out of my teeth and decided to compare actual average MPG with the average the onboard computer gives.
So, I fuelled the car to the brim on Tesco Super unleaded, pretty much on cruise at 70 mph all the way, apart from a few blasts when leaving a service station.
I refuelled immediately upon my return and the Ave MPG reading in the car was 42.2mpg, obviously happy with that.
I recorded the amount of fuel required to fil to the brim = 36.35L, divided this by 4.5 to get gallons = 8.07
Then divided miles covered = 330.8 by gallons = 40.99 mpg (actual).
Pretty accurate by anyones standards I reckon...
23i - 2009 - 81500 miles
Just finished a 330.8 mile topless drive (roof down, not shirtless). Hull to Plymouth, four rain showers, one very heavy but I stayed dry. Just finished picking the flies out of my teeth and decided to compare actual average MPG with the average the onboard computer gives.
So, I fuelled the car to the brim on Tesco Super unleaded, pretty much on cruise at 70 mph all the way, apart from a few blasts when leaving a service station.
I refuelled immediately upon my return and the Ave MPG reading in the car was 42.2mpg, obviously happy with that.
I recorded the amount of fuel required to fil to the brim = 36.35L, divided this by 4.5 to get gallons = 8.07
Then divided miles covered = 330.8 by gallons = 40.99 mpg (actual).
Pretty accurate by anyones standards I reckon...

....well impressed with that and the OBC is pretty accurate when worked out manually.