Strange

[faugh a ballagh]

I have a w210 320 cdi, yesterday i done 111 miles from 7.30am till 4.45pm this included rush hour traffic, it cost me £25.11 to top the tank back up to full (i do this every day) today i done 91 miles from 7.30am till 4.15 again this included rush hour traffic, amazingly the tank took £10.13 to fill it back up a difference of 20 miles and nearly £15 i am stumped totally stumped

 

[jberks]

I'd guess at a little more stop/start and braking from 80 yesterday and more steady 60mph today - not always noticable. Plus you were probably being more gentle today too.
I also find that rain costs me 4-5mpg (due to those fat tyres).

 

[verytalldave]

Thats a BIG difference. Well over half the consumption of the previous day. About the same as 20mpg one day and 50mpg the next. I cant believe such a difference can be explained away by simply driving conditions. However I cant offer any reasonable explanation either.

 

[Blobcat]

Heated seats, rain, rear demister and traffic all make big differences to fuel economy. I would also add that depending upon how the pump cuts off can also make quite a difference to how much you can get in as well as if you park with the car leaning to the left or right. My W210 would cut off the pump then show between 13.2 to 14,2 Gallons, not quite as easy to tell on my W211 as I just have a bar graph.

 

[faugh a ballagh]

thats all in and around town driving in belfast city centre and the roads into it, average speed was i think in and around the 19mph mark, i was ready for selling it on monday night lol but have calmed down a wee bit from then

 

[dirtymonkey29]

for the last few weeks i can only acheive around 65 miles from full to 3/4 full.....65miles and using a quarter of a tank seems really really bad to me. i got a w210, e300 turbo diesel v reg 1999

 

[verytalldave]

Sometimes fuel gauges arent linear over a certain part of its travel. I once had a car that stayed at half full for ages then all of sudden would drop to a 1/4 over a distance of about 15 miles.
If you really want to do an accurate test, the only way is fill up to the brim and drive around until its nearly empty and then refill - again to the brim and calculate to MPG used over the distance travelled. Do that 5 or 6 times and then average it out. That gives you a pretty accurate idea of your cars real MPG figure.
Dont take too much notice of a 25% travel of a fuel gauge.