Interesting point re. competitive fuel economy entries. The site is already open to that of course, but I can see what you mean that it would become more likely if the direct comparison were made. A one-off snap-shot now would be helpful and wouldn't cause this problem...

I'm not convinced by your last point though. If by 'similarly specced' you mean cars of the same size, weight and age with near identical engines then your point is true but not really helpful. If you're comparing cars with different engines or ages (which many buyers will be) then there are very real differences. This is especially true when consumers are often trying to compare their current cars with newer models.

There's always someone that claims to 'average' 30+mpg from a V8 petrol disco while towing a caravan etc. You could use statistical techniques to remove outliers from the data group, but this has its own problems.

I agree. Some people seem to quote the instantaneous consumption figure, or zero the MPG counter when they're up to speed, with the engine warm.

I saw someone on a caravan forum recently claiming an MPG figure (when towing) which was better than the manufacturers official figure for the car alone.

We've all seen fantastical figures that way, but long term averages are far more useful!

Its a little bit like when someone asks for advice on a car. Instead of listening to the requirement and advising, many forum members just pile with a recommendation of their favorite brand/model. And rubbish every alternative suggestion.

This phenomonon isn't just on here though - I remember reading research which said that most casual buyers of What Car? had just made their purchase, and were buying the magazine as some form of validation.

At its worst, this 'tribalism' descends into rubbishing other people's purchases. Often with scant evidence.

Edited by Marlot on 23/06/2013 at 10:29

There's always someone that claims to 'average' 30+mpg from a V8 petrol disco while towing a caravan etc.

As one who once owned a V8i Disco, that gave me an attack of the giggles. About the only positive thing that could be said about its fuel consumption was that adding a caravan to the back end made no discernable difference to it.

It was always terrible to the extent that if you're worrying about how much fuel you're using in one, you have bought the wrong car.