Reduced Mileage

[TranceTrousers]

I've noticed lately that I'm not getting as many miles out of my Aygo as I used to.

Up until a couple of months ago I was always getting well over 400 miles from a full tank. On one occasion I got as many as 450 miles. Since then, though, I'm getting significantly less, at least 40 miles less.

I've changed the air filter, which I read could affect fuel consumption, but it had no effect. I also had a tyre with a slow puncture replaced, as I thought the reduced air pressure might have been causing some rolling resistance and hence increased fuel consumption. But that's had no effect either.

Does anyone have any ideas as to what might have caused this sudden decrease in mileage?

[FROSTYBALLS]

The colder weather will have a detrimental effect on fuel consumption.

[TranceTrousers]

How so?

[FROSTYBALLS]

Examples:

http://www.theaa.com/motoring_advice/news/aa-fuel-for-thought-increased-cost-of-winter-motoring.html

http://www.fuelimprove.com/blog/fuel-economy-winter

[Wiz201]

I usually do max 320 miles with mine before filling up, usually it takes 27 to 28 litres out of 35 total capacity of the tank and its usually on its 2nd to last fuel guage marker. It got to 295 miles on that guage on Monday, but despite having opportunties to stop for petrol on way home from work in Bradford on Monday, I made it go a bit further to Brighouse before getting petrol so it was 300 miles dead and it still took just 27 litres so I'm not always sure those guages are accurate.

Work is 15 miles each way so it always has a good run 5 days out of 7. At the weekends if I'm popping up to my mum's five minute journey I usually take the long way round so it does warm up to temperature. If I go the short route its there before its warmed up.

[TranceTrousers]

The colder weather will have a detrimental effect on fuel consumption.

Wow, I never knew that! I'm even more surprised because I never had anything like this happen with my previous car.

[Cyker]

On the bright side, the cold acts like a natural intercooler so you get a bit more power compared to summer :D (Well, once the engine warms up... )

The drop is worse for us diesel and HSD drivers tho' as the engines generate a lot less waste heat so it takes forever for the engines to warm up to optimal operating temperature!

[ghori1989]

I get about 300 miles out my tank (69k on the clocks, slipping clutch and a heavy foot). Fill it up when its on its final bar.