Thursday, 23 April 2015

Fuel Economy

From The Telegraph

Consumers could be spending an average of £133 more on fuel a year than they thought they would as a report by independent consumer company Which? suggests manufacturers are misleading consumers by overstating the fuel-economy figures to make their cars seem more efficient.

They aren't overstating their fuel-economy figures. They're figures that are the results of standard tests. What the car makers do is to set up their cars in the best possible way for those tests.

The report found that only three of the 200 models tested by the company across 2013 and 2014 reached the official miles-per-gallon (mpg) figure stated in information supplied by their manufacturer, with cars falling short by an average of 13 per cent.

Yes. Because you aren't optimising cars like car makers are

In addition, the test is carried out with all ancillary loads turned off, meaning that air conditioning, heated windows and lights are all turned off to increase efficiency.

Roof rails, extra lights and door mirrors can be removed to make the car lighter and there is no restriction on the air pressure of tyres.

Like that...

As a result, Which? is calling for the European Commission to introduce its new testing procedure in two years’ time, as scheduled, despite it "facing heavy pressure from the car industry to delay the change until 2020".

It says the process "needs to be completed properly without rushing to meet unrealistic deadlines, so that it is robust".

Why? The tests work fine as they are. Every manufacturer pulls the same tricks which means that in general, comparing cars still works. Except hybrids. And if you're driving one of those, you aren't thinking much about money anyway. OK, there's that £133 but it's not like that's much of a deal breaker when you're spending £15K on a car.

If you're money-conscious you don't buy new cars anyway but let some other schmuck another driver subsidise your driving.


Lola said...

Thanks. Saved me the bother. This whole thing is just to try and justify more interventions - which won't work. WhatCar already publishes 'real' economy figures, so the market has already sorted this. The whole thing is pointless.

Mark Wadsworth said...

Oh who cares? As long as all the manufacturers cheat to the same extent, then their fuel consumption figures are still very good RELATIVE guides, so if you buy Car X because it uses less petrol than Car Y, does it matter that actually both cars use more than claimed?

No, because what you are looking for is the lowest fuel consumption for that class of car, and you have bought it.

In the 70s, 30 mpg was considered pretty good, nowadays 60 mpg is pretty good and 30 mpg is appalling, and one day 90 mpg might be normal and 60 mpg considered a gas guzzler.

Steven_L said...

They really need to get rid of these emissions targets, they are bollocks and the quoted co2 and mpg figures are bollocks as the independent reviews always show.

They keep journalists in business, but the result is that everything is now turbocharged, less reliable and more expensive.

If something sounds too good to be true it probably is. So when Ford claim their 1 lite turbo fiesta has the output of a 2 litre normally aspirated engine but does 60mpg, sure enough, it actually does 35mpg if you drive it like a warm hatch.

The best trick is actually the latesst VAG wheeze of 4 cylinder turbo engines that run on 2 cylinders for the test but not when they are actually on a normal road.

But you pay an extra couple of grand for this technology, so VAG basically pocket your tax saving.