Cash-strapped motorists can now accurately gauge how much fuel their car is likely to use
27 April 2012

Cash-strapped motorists are now able to more accurately gauge how much fuel their car is likely to use.

A new online tool, developed by What Car?, allows drivers to access real-world fuel consumption information. What Car? True MPG has tested cars under the same conditions motorists face every day.

Until now, car buyers have needed to rely on manufacturer's figures alone. The system to determine this information is set out under European law and conducted in laboratory conditions.

The data provided by What Car? True MPG has been gathered using a portable emission measurement system once the cars' engines have reached normal operating temperature. Engineers then test the cars over a variety of roads including motorways, A- and B-roads, and through towns and villages. The data from the testing considers driving style, changes in altitude, ambient temperature and humidity and engine temperature.

The equipment measures carbon dioxide, carbon monoxide nitrous oxide, nitrogen dioxide and total hydrocarbons. From the CO2 output and knowledge of the exact fuel in the tank, the fuel consumption can be calculated with a high degree of accuracy.

What Car? editor-in-chief Chas Hallett said: “With rising fuel prices, the miles-per-gallon issue is high on every motorist’s agenda. Countless car buyers are frustrated that they don’t match the official government fuel figures.

"What Car? True MPG will allow motorists to select a car personalised to their driving needs and budget. We hope that it will become invaluable in the complex and emotional car-buying process."


Join the debate


27 April 2012

Your report says that all the measurements are taken once the car has reached normal operating temperature, but surely this just compounds the failings of the official figures as they also relate to a heated engine. We do not all drive taxis that are operated on a 24/7 shift pattern.

Every private motorist gets into a car that is cold, so surely how quickly a car reaches optimum temperature is a significant factor. BMW (among others) use flaps behind the grille that stay shut to enhance aerodynamics until the engine needs them to open for cooling; surely this should be factored into real world mpg?

And what ambient temperature is being used for the testing? Is it an average over a range of what we experience in Northern Europe or based upon the average for the year, because the average mpg on my trip computer is so much better when the outside temperature is above 10 degrees C.

I realise it is a challenging subject, but detail of the basis of the measurement is required to determine how relevant it is to those who may wish to rely upon it.

27 April 2012

Might become useful when it gets a fuller database of real cars.

27 April 2012

[quote fellwalker]

Might become useful when it gets a fuller database of real cars.


Hear Hear. None of my cars, present or past, are featured.

27 April 2012

Mine either, no Honda or Citroen featured!? I'm all for more clarity on this topic but I would thought it would have been more complete. How will this compare to the Honest John real mpg listings? You submit your own figures on there and it is very complete.

27 April 2012

Whatever the pitfalls and problems, at last the motoring press are finally taking this issue seriously. At least this will provide some sort of comparative tool, even if it isn't perfect.

If you want a bigger database have a look at the Honest John website. He has been running a real fuel economy register for about 9 months.

27 April 2012

It is nothing more than a shameless advertisement for Tesco petrol. I'm really disappointed with What Car on this one.

Presumably, it is only there for stupid people who either can't tear themselves away from tesco, or who have no idea about fuel economy. I would have thought that most of us on this forum have the sense to understand that if your diesel hatchback says it'll do 65mpg officially, and you drive most of your time in traffic, and then redlining it, you're not going to see more than 40mpg...

like everything else in this world, it's only there for the lowest common denominator!

27 April 2012

What ever your thoughts are on this (Tesco's ad or not), this is likely to spark a wider debate, especially in the regular press and other news channels. This can only be good for getting something changed.

Already there has been comment on it in this mornings Radio 4 news bulletin.



It's all about the twisties........

27 April 2012

Oops, did something unforgiveable....commented on the Fuel Tool, before looking at the website. Now feeling a bit of a tool, as I didn't realise quite how limited the test results are. You would have thought that they would have done a great deal more before launching this. None of my three cars features on this, Jaguar doesn't even have one model tested....there aren't any petrol Mercedes Benz there.

Honest John website far better, as it takes numbers from real drivers and isn't trying to get me to go to Tesco...

I'll get my coat.

27 April 2012

I know roughly what I'll get from any car. My driving has stayed the same for a few years (same commute etc.) and its official urban + 3 on average. Worst was the 3 series (pre efficient dynamics) which delivered urban +0. Best is my current car - current Mondeo 2 litre petrol which is giving official urban +7. Must be getting older.

27 April 2012

There are already several better websites for real-life fuel consumption. This is a pointless exercise.


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