I know it's a difficult one to answer but on a 20VT what, assuming I'm driving normally and not thrashing the living granny out of it, should I expect in MPG? I put £40.00 in yesterday and I've got about 120 miles! Seem a little high considering I was taking it really easy.
What's everyone else getting?

120 miles per gallon seems pretty damn good to me

To be told, in harmony, by the moderating team...."Use the search engine!"

Seriously, this is one of the questions that is rapidly approaching "What type of oil should I use?" as the most often asked question!

It varies so greatly anyway, due to driving styles, differences in wheel sizes, tyre makes/brands/tread depths, road conditions/layout/gradients/traffic, but after a quick search you'll find some of the previous threads where there is a range of figures given, from the sublime to the ridiculous!

First things first though, you need to work out accurately what your consumption actually is: £40 per blah blah miles is meaningless. You need to do several full tank journeys, taking a note of the distances covered and the amount of fuel required to refuel, then work out an average. At that point you'll know what your average consumption is. If it turns out to be 19mpg, then you've got an issue, either mechanically, electronically, or with your right foot!

yes - that's high - normal driving should get 25 - 30 mpg, which is about 250 - 300 miles on a £55 tank

You should check your running temperatures - when the thermostat fails, it tends to stick open, which fools the ECU into thinking the engine is running cold, which then delivers more fuel to compensate

However, sometimes, the fuel gauge is a pathalogical liar and will show half-full after 100 miles, then take another 200 miles for the second half of the tank

the only way to be sure is to fill up, zero the trip, drive around for a few days, then fill up again and calculate the MPG from the fuel you put in the second time

FWIW, I struggle to get less than 300 out of a tank under normal driving conditions

That's what, just over half a tank?

For a full tank I get about 260-300 in rubbish town-only short distance commuting, 400+ on a fast motorway journey.

Used a LOT more fuel when the 'stat went though (= low coolant temp, not above 75deg)

I usually expect to get to about 320 miles from a full tank before the light comes on.

That's with driving mainly on A roads.
If the missus take sit down the motorway a few times we might see about 600 miles* (if I believe her when she says she drives at 55-60 )





*Aye, right.
Haven't seen 350 on a tankful in 6 years and 50k miles.

I have been tracking my fuel consumption for the past month (so thats about 7-8 tank fulls), managing a consistant 32-33 mpg.

At the moment i'm doing a month or so on Tesco 99 to see if it makes any difference.

So far it has made none whatsoever

Sorry it's such a daft question, I realise there are so many variables to consider. I have a feeling that my thermostat needs changing, the temperature seems to sit at 70 then shoot to 90 then back to 70 and sometimes lower. Does that sound like a stat problem?

Yes, definitely

Thanks Nigel.

I use my iphone app "roadtrip" and average 27mpg.

I had the same sort of problem with my 16vt. Changed the thermostat and still got thr same readings on the gauge.
Maybe temp sender noy thermostat.

I've been using the iPhone app Road Trip too. It's been as low as 21mpg and as high as 38mpg. Everytime over a full tank. It averages 28mpg with a mixture of driving styles.

Which century did you last put a full tank of fuel in or are you only putting in 3/4 of a tank.....meanie

It may not be the thermostat.....could be the sender that sends the temps to the ECU.
Could even be a lambda problem thinking your car is running lean (0.2V) which could also mess up your fuel consumption.
There are too many variables and it could be any causing the bad fuel consumption.