MSE News: Government miles-per-gallon car figures 'unreliable'

losinj

Mr Baker was at pains to point out that official figures are meant to indicate relative fuel economy, but I'm guessing a big %age of the population may not realise this when choosing a new car - after all, why should they, unless they read all the small print?

It could benefit many people to be able to refer to a banding system for fuel economy, like for road tax and car insurance. Slightly odd there isn't one already, although a previous poster suggested a possible reason why the Government would be very happy for us to continue sucking up the published figures.

crittertog

HappyMJ wrote: »

I've spent 3 weeks driving a brand new 2012 Kia Picanto 2 Ecodynamics 1.25L car. Supposed to be 65mpg ... By my calculation I think that's around 43mpg.

It will likely improve over time, though, as the engine looses up a bit (people say this about VW's diesel engines, and I assume it applies generally).

patman99

Well, first set of figures in. Managed 414 miles on £50 worth of fuel.
Filled it to the brim. According to the iPad app, the mpg is 44 mpg. This will increase as more readings are input and it gets more accurate.

chalkywhite

These tips come from an American petrol company employee.Save more fuel by filling up early morning when its cold as its less likely to evaporate when filling. fuel is slightly denser coming through cold pipes and therefor you get a fraction more. keep tank as full as you can because more air space means more evaporation due to sloshing about. Ever got a sudden whiff of fuel fumes on opening tank cap. Yes I know advise is to normally run tank on low because of weight, but I now get 52 mpg with my 2litre mondeo turbo deisel. Computer trip reading 52.4mpg; average speed 28mph this morning Averaged 51.4 on return trip to Alicante and I didn't use a single toll road. Why waste money on tolls when you're trying to save it on fuel. My son chooses his company car for economy and not for looks or bragging. He makes a few pence a mile to add to his wage. Research thoroughly before choosing and be very gentle on the loud peddle.

grizzly1911

jeferey wrote: »

Brim to brim calculations are the most accurate way to measure mpg.
clangnuts is right - I drove over 700 miles on a tank once last year, low fuel light came on, did another 50 miles , indicated range dropped to 0, did another 15 miles, finally got some diesel (previous garage was empty!) and I still had 3 litres left in the tank. Wouldn't recommend it though :eek:

Not recommended in Diesels because if they get too low or you run out they need re- priming once you have turned them off. AT best it will be endless churning on the starter motor at worst doing it manually.

I knew about it but had no choice once due to fuel shortages. Limped into a service station OK but sat red faced at the pump, after filling, as I tried to coax a new Vectra into life.

grizzly1911

patman99 wrote: »

Well, first set of figures in. Managed 414 miles on £50 worth of fuel.
Filled it to the brim. According to the iPad app, the mpg is 44 mpg. This will increase as more readings are input and it gets more accurate.

Whats wrong with a calculator or do it in your head 4.5l near enough = 1 Gallon?

grizzly1911

almillar wrote: »

This is a misleading headline written, I guess, by a journalist looking for attention on a slow news day.
The figures are 100% accurate - they're tested under laboratory conditions, for the same 2 driving patterns, for all cars.
Then school run mum comes on saying she sits at traffic lights and start-stops and has used up 1/4 of a tank and the computer only says 20mpg?
Who do you believe?
Everyone has different driving patterns, plenty of people don't even have a pattern.
In your current car, if it's in good condition, and the official figures say a combined 30 mpg, and you get 20, then it's safe to assume that for your driving pattern, you can knock 1/3 off ALL combined figures for ALL cars. Then you won't be so disappointed with your next car.
I know, for example that I can just about get the combined figure with my driving pattern, and that's what I have done in my last few cars. Longer runs, or 'enthusiastic' runs will affect this of course, but if you're not calculating your MPG properly (brim to brim as above) then don't bother posting about your MPG as it's probably inaccurate.

^ ^ ^Spot on.

jeferey

grizzly1911 wrote: »

Not recommended in Diesels because if they get too low or you run out they need re- priming once you have turned them off. AT best it will be endless churning on the starter motor at worst doing it manually.

I knew about it but had no choice once due to fuel shortages. Limped into a service station OK but sat red faced at the pump, after filling, as I tried to coax a new Vectra into life.

Agreed! Filled up this week as soon as low fuel light came on and still had nearly 7 litres left. Managed 688 miles at 60.9mpg too out of my Honda 2.2

mpjod

I take this scandal as seriously as the ppi scandal and we should be compensated for the additional costs incurred by ourselves because of the discrepency between the fuel figures advertised by the motor companies and the actual figures acheived. this is a significant amount of money over many years.

mpjod

I was informed upon buyinmg my car from a main dealer that i would get 46 mpg. I keep track of my fuel use and have never had more than 33mpg this is a massive difference. I have tried every conceivable way of driving and the figures are the same every time. I dont rely on the cars computer to tell me I do the figures myself using the amount of fuel required to fill the tank against the amount of miles I have travelled, its scandalous and represents a fuel bill that is 25percent more than I was promised.