fuel consumption on my 325

Post Mon Sep 02, 2013 4:11 pm

Just after sorting out my 325 I got 685 kms out of a tank on a long run.

Sound great but then that's only 423 miles and considering I have a 15 litre extra tank to go with the 55 litre standard one it works out at about 30 mpg, I was still impressed though!

Post Mon Sep 02, 2013 4:37 pm

jas025 wrote:
Speedtouch wrote:
jas025 wrote:Mine was appalling the other week (about 13mpg) but mainly very short journeys and I also isolate the battery when it's not in use and a couple of people have said that doesn't help as the ECU needs to relearn how the engine's performing (or something).

Got 25mpg going to cranleigh and back - much happier with that.

How long does it take for the ECU to settle in if the power's been cut? Could that help explain some of the poor figures people have had?
It is true, that the ECU will need to re-learn its settings following a power outage. However, it should only take a couple of miles or so to establish a reasonable standard of running, so unlikely to affect the mpg by that much. If your 325i is only doing 13 mpg, something is seriously wrong with it, although if you were doing stop-start London driving, maybe that's about right...
A mix of either rush hour driving over speedbumps and trundling round the suburbs.

Still - it's quite a shock when you fill it up and realise that you've gone nowhere and spent £55.

I think I suffer from the same problem as others on here as well - I never get anywhere near the capacity of the tank and the warning light's never come on either even though it looks pretty empty according to the gauge. At 22 years old it's probably one of the bits on the car that I wouldn't trust to be accurate or work (a bit like the windscreen washer empty warning light - a truly annoying pointless thing - already replaced, now bypassed).

The fuel warning light is surprisingly reliable. Of course, yours may be broken - but they generally come on just as you're becoming convinced that they're broken. The needle drops to E and then the light comes on.

Post Mon Sep 02, 2013 5:49 pm

Iv just filled my tank again. Iv done 316miles on a full tank inc driving to gaydon show and running around town to work and back.

Post Mon Sep 02, 2013 7:08 pm

jonny323i wrote:Iv just filled my tank again. Iv done 316miles on a full tank inc driving to gaydon show and running around town to work and back.

Is that in a 325i...?

I have just calculated mine, 1 weeks driving, Isle of Wight trip +- 160 miles and then another 56 miles London driving gave me a total of 216 miles between filling up. Filled her up and put in +- 41 litres.

Therefore by my calculations my average was +- 23m/g.

Post Mon Sep 02, 2013 7:14 pm

Yes 325i touring the computer says av 27.6 mpg and I carry a boot full of tools a lot of the time.

Post Mon Sep 02, 2013 10:12 pm

Morat wrote:The fuel warning light is surprisingly reliable. Of course, yours may be broken - but they generally come on just as you're becoming convinced that they're broken. The needle drops to E and then the light comes on.

Indeed. I regularly used to run my two 320i and 325i models down to the warning light, then bung in a tenner's worth of juice.

I typically got around 45-50 miles before the warning light came back on again, giving a reassuring 26 mpg or so.