Fuel range differences

[Ki3r]

I've just filled my car (528i) up with £70 of petrol (Momentum from Tesco if it makes a difference, at 135.9ppl) My OBC says I have a range of 352 miles.

In the past I have filled my car up (until it clicks) and it will have a range of normally between 280 to 320 miles. It doesn't matter if I use Tesco's normal unleaded, their Momentum, or Shell V Power.

Any ideas on why it could be like this? Not that I'm complaining getting more miles, just interested in why it happens.

[fatboy b]

Range on the computer is normally based on the previous 30-50 miles of driving, and the contents of the tank.

[sparks_E39]

It depends how you have driven it over the last tank. My 528 ranges from 350-400 miles on the display. when it's full. It has said 550 a couple of times, and it did it too...

[FamilyDub]

IIRC my car's (MKV GTI) 'range to go' is the average consumption over the last 40 miles x fuel remaining.

It's anything from 315 to 375 range when filled.

[sparks_E39]

The E39 computer is for the most part optomistic though. It over reads MPG (30 mpg displayed on mine is around 27-28) and under-estimates how much fuel is left. There is a way to calibrate it, but I haven't bothered. I've driven 30 miles on --- before and it still only took 65 or so litres. You are doing right to fill it with the good stuff though, your 528i has a different engine to mine as mine is a late twin vanos one, but it likes the higher octane stuff. Doesn't do better mileage though. Great cars

[Ki3r]

Ah that makes sense. Thanks.