Quoted mpg figure v's actual mpg

decsdad

Thought it would be interesting(would be for me anyway) to compare cars quoted mpg figures with actual mpg figures achieved with normal use.

I'll start

Citroen Belingo 1.9d, 2003, claims 40.9mpg,(107k) actual 40mpg

Wifes car,

Audi A3, 1.9TDIe, 2008, claims 62.8mpg, trip says 66mpg since new(55k), I checked it on one tank and it was correct.

LeeSouthEast

2003 Ford Focus 115ps 1.8 TDCi claimed (iirc) 50-ish, get 64mpg.

mollypoppy

2009 Volvo S40 1.6 Drive S/S claimed 72.4mpg does 42mpg not a happy camper

I_am_mad

Citroen C2 1.4 HDI SX claimed to be atleast 75 mpg and actaully does about 58.7mpg the highest we have ever got was 65.

casper_g

Vauxhall Astra 1.7DTI ECO4 claimed 64 mpg (combined cycle), actual measured 67 mpg (A-roads/motorways).

movilogo

For any car, with considerate driving, you should be able to achieve 80-100% of quoted figure.

If not, either your driving is bad or manufacturer lied about fuel economy figures.

bryanb

movilogo wrote: »

If not, either your driving is bad or manufacturer lied about fuel economy figures.

Yes but how do we know which?

Kilty_2

Vauxhall Astra 1.6 Twinport (Z16XEP) - claimed 42 mpg combined - actual 40.7 (and I don't hang around on the m/way)

:T

anewman

02 Skoda Fabia 1.4 MPI 8v 68bhp (Skoda OHV engine) - getting a rather disappointing 32.6mpg average - MFR's claim 39.2mpg combined (6mpg less).
94 Skoda Favorit Estate 1.3 67bhp high compression version (the Fabia engine is based on this one) - I got 37mpg on average, MFR's claimed approx 42mpg combined (5mpg less).
In both cases I had a heavy right foot, more prone to going closer to the rev limiter in the Fabia as it sounds less like it's about to explode, lol. I thought the more advanced injection system on the Fabia would mean better MPG, but obviously not. Have read on the net that changing the MAP sensor on the Fabia can significantly improve MPG, even if the ECU hasn't logged a fault for it.

OP might wish to take a look at http://www.spritmonitor.de/en/ which is a site people can log fuelings and calculate MPG for their car (you can browse and search through the cars).

Altarf

movilogo wrote: »

If not, either your driving is bad or manufacturer lied about fuel economy figures.

You also need to take account of the fact that the test doesn't really represent reality, and is only meant to be a way to compare one car against another -

The Urban test - A "cold" start, where the car is 25c (perhaps cold for a morning in California, but a bloody good summers day in the UK), "driven" on a rolling road for 2.5 miles with everything turned off (no aircon, lights, etc). A maximum speed of 31mph, but the car only averages 12mph over the 2.5 miles. So not exactly zipping along.

The Extra-Urban test - It immediately follows on from the urban test, so the engine is nice and warm, and covers 4.3 miles on the rolling road. A maximum speed of 75mph, but the car only averages 39mph over the 2.5 miles. So again not exactly zipping along, especially when you realise that they only hit 75mph for a few seconds, and they are allowed (and always take) 50 seconds to get from 0 to 60!

The combined figure is just an average of the two tests (weighted for distance).

So if you are the sort of driver who does -

a) Short journey from a 'real' cold start and doesn't drive like a nun on their way to a funeral, then you will get much worse fuel consumption than the tests;

b) But if you do long journeys with mile upon mile of light-throttle motorway cruising, then you will probably get as good as, or better than the tests.

The trouble is a lot of small diesels with high MPG figures are being sold to type a drivers, who then wonder why they don't get the high mpg figures.

smitchy73

Had a toyota Aygo, claimed about 65mpg, actual about 60-62mpg

Had Jeep Patriot, claimed 42.2mpg(combined), actual 40mpg.

Now Chrysler Sebring 2.0crd Limited claimed 48mpg combined, actual(today 49) long motorway run up to 62mpg.

Have a Golf Bluemotion on order, claiming 74mpg, lets see what I'll get.