Average MPG has dropped since service and MOT?

forgotmyname

If i showed you my average mpg you would think i was running a large petrol V8 4x4 towing a house and not a fairly economic diesel

Very short journeys and leaving it running because it is not being used for a good few days at a time. Nearly 3 weeks unused at one point.

agrinnall

You would have to drive with a very light foot indeed to achieve 57 mpg on your trip computer, I've only once had it above 50 mpg on my 1.0 Fiesta, and that was when I did a long stretch of restricted speed motorway driving. The figure you're getting now seems far more realistic.

Edit: Actually, if it isn't an eco-boost engine then it only has 78bhp, and has a listed consumption of 65mpg, so I guess real world 57mpg might be possible. I can't imagine it's a lot of fun to drive with so little power though, even the basic eco-boost has another 21bhp, and mine has 26bhp on top of that.

https://www.parkers.co.uk/ford/fiesta/hatchback-2008/10-zetec-3d/specs/

n217970

Mine has dropped by 15% since I started to see negative numbers on the temperature guage on a morning. Its taking twice the distance to get up to temperature and its really thirsty when cold.

DoaM

WobblyDog wrote: »

4) Increased rolling resistance on wet roads.
5) Increased rolling resistance of cold hard tyre rubber.

Really? I would have thought the opposite would apply. (Wet weather = less grip; cold, hard tyre = less friction. I suppose less grip could mean wheel spin and loss of drive versus fuel usage, but .........)

n217970

DoaM wrote: »

Really? I would have thought the opposite would apply. (Wet weather = less grip; cold, hard tyre = less friction. I suppose less grip could mean wheel spin and loss of drive versus fuel usage, but .........)

When the road is wet your tires have to push the water out of the way and rolling resistence is increased..

hareng

Noticed the substantial decrease 3 weeks ago, common on every car i have ever known.

Just the cold factor alone will knock it down a good 10%.
So if you were achieving 42mpg you wouldnt get 38mpg.

Mixed road driving your assured an additional 10% decrease in mpg due to a light rain ie fast intermittant. Heavy rain 3 weeks ago can knock it down as much as 25% on top of cold factor on a run.

If your thermostats gone in cold weather that can knock it down 40%

GunJack

Tarambor wrote: »

10% drop in my Mondeo from November to around February.

I noticed on my diesel fusion on the last 2 tankfuls...this cold snap has hit mine about 10%, along with virtually all driving at this time of year needing headlights on, heater going, etc.

bill_the_bus

Thanks everyone for your replies. Did the work run yesterday and up to 50.1 so hopefully it may just be down to outside conditions, have to hope the garage did everything as they should and it will climb again in the spring. In reply to the comments i am light footed, i drive for a living so read the road, leave a gap so when the traffic in front breaks i ease off the gas and often do not have to use the brakes. My average speed is mid 30s so even though there is no motorway or dual roads i am not stop starting too much.

On the issue of it being an EcoBoost or not, how do i find out. There is nothing listed on the paperwork and no badges but as i said it was purchased as one.

agrinnall

Try something like this to find out what engine you have.

https://vindecoder.eu/ford

forgotmyname

I have a Mondeo diesel and currently under 30MPG. Before you say its faulty i recently did a trip from the Midlands to the coastside of Cumbria AND back on a single tank of fuel. Better than that i was towing a caravan. So its not faulty

I wont drive away until all the windows are clear though. Short winter journeys just kill the economy.