An interesting piece on petrol vs. diesel in the Telegraph

[Funk]

I was fairly impressed with this piece from Dan Prosser. I can't be alone in the irritation of 'official' mpg figures being nothing like the real world (I always knock 15-20mpg off the official figure in my head). This article puts two Skodas head-to-head in the real world.

http://www.telegraph.co.uk/motoring/green-motoring...

The results aren't surprising with the petrol losing out to the diesel, but the life-cycle costs are a little less convincing.

Why are manufacturers allowed to continue to spout increasingly-erroneous figures? Much like a speedometer, it seems the higher the claims are, the further out they are in the real world.

[va1o]

MPG figures for both are pretty poor to be honest.

[twazzock]

Funk said:

Much like a speedometer, it seems the higher the claims are, the further out they are in the real world.

Oh yes. Been driving a Bipper recently which Peugeot claims will achieve 60+MPG (with ease!). Currently showing HALF that on the trip computer. Admittedly its usage is the complete antithesis to economical driving but that is still utterly dire to me, for a modern 1.4 diesel!

[Funk]

But they are, arguably, what most people would expect to achieve in the real world with a mixture of driving environments. And that's kind of my point; the 'official' figures are often pie-in-the-sky.

[redtwin]

The "official" MPG figures are determined using "official" test criteria, so that makes them, well, "official".

Not their problem that the average motorist chooses to drive otherwise.

The salad dressing I buy states it has 8 servings per bottle, I can only get 4-5 servings from it. Who can I complain to?.

[ZeeTacoe]

I'll spend that 5 quid not having to listen to a tractor nor endless drone about in gear performance

[Funk]

I put it in the same category as broadband. The old 'up to xxx..' routine, when in fact the average user gets nowhere near. Given the disparity, is it not clear that the 'official' measurements aren't in any way representative of the way people have to drive in the real world?

[zakelwe]

va1o said:

MPG figures for both are pretty poor to be honest.

Too true, what they did was not real world driving, they went from one extreme to another and got too low a figure. So it is no better than the super figures at the other end of the spectrum. Allowed them to earn some money doing journalism though.

Andy

[diddly69]

Well said Zee!

[williamp]

Yes the official tests might not be the same as YOUR real world comparison. However they are the same for every vehcile, so you can make a valid choice between vehicles based on MPG. You might not get the same MPG as the official figure, but you will get better MPG on a vehcile with a higher official MPG figure.

[Funk]

ZeeTacoe said:

I'll spend that 5 quid not having to listen to a tractor nor endless drone about in gear performance

Yet your profile says you drive a diesel....?

[LuS1fer]

Can't honestly reacall the last time I cared what mpg a car gave - save perhaps dripping a hire car back to the airport on empty. I drive what I like and if I need to economise, I go slower, knowing that to change the car would cost me far more than continuing to fill the tank.

[va1o]

zakelwe said:

va1o said:

MPG figures for both are pretty poor to be honest.

Too true, what they did was not real world driving, they went from one extreme to another and got too low a figure.

I am adamant that on the majority of cars if you go for a sensible motorway run you will achieve at least the official combined figure, assuming its run in and driven correctly.

[kambites]

Yes but the combined figure isn't meant to be a motorway figure, it's meant to be a combined figure. The official extra-urban figure for a car is typically a good 15% above the combined figure, and achieving that on the motorway would be a challenge.

[Funk]

LuS1fer said:

Can't honestly reacall the last time I cared what mpg a car gave - save perhaps dripping a hire car back to the airport on empty. I drive what I like and if I need to economise, I go slower, knowing that to change the car would cost me far more than continuing to fill the tank.

I do a lot of mileage and the cost-per-mile starts to become very relevant...!

kambites said:

Yes but the combined figure isn't meant to be a motorway figure, it's meant to be a combined figure. The official extra-urban figure for a car is typically a good 15% above the combined figure, and achieving that on the motorway would be a challenge.

Indeed.

Anyway, I just thought it was a good article in that it highlighted the misleading manufacturers' figures. IIRC, aren't those 'calculated' and not actually even taken from a real engine?

[va1o]

kambites said:

Yes but the combined figure isn't meant to be a motorway figure, it's meant to be a combined figure. The official extra-urban figure for a car is typically a good 15% above the combined figure, and achieving that on the motorway would be a challenge.

Yes but its about managing expectations, realistically the official combined figure is what you get on a motorway run and the official urban figure is what you average overall. Its only when it gets below that when things become a problem IMO

[anonymous-user]

37 mpg from a 100bhp little car sounds pretty low for a 200 mile motorway run at 80mph. Not all the way through the article yet, but that seems strange.

You must be really thrashing a 1.2 to get 14 mpg out of it too, goodness me.

Edited by MSTRBKR on Thursday 28th April 23:04

[va1o]

Also they have chosen the 1.2 TSI and 1.6 CR TDI engines in the Fabias. Go onto any VAG owners forum and it will be awash with complaints that these two units in particular, whatever the car, really struggle to achieve what they are supposed to, with many people taking them back to the dealers to complain.

[redtwin]

Funk said:

Given the disparity, is it not clear that the 'official' measurements aren't in any way representative of the way people have to drive in the real world?

It is crystal clear, however what needs to change is the testing procedure/criteria. Can't knock the manufacturers operating within the specified rules.

[ZeeTacoe]

Funk said:

ZeeTacoe said:

I'll spend that 5 quid not having to listen to a tractor nor endless drone about in gear performance

Yet your profile says you drive a diesel....?

I'm giving the poor thing absolute death though, so it'll explode and I'll be forced to buy a nice petrol convertible sports car. Knowing this bloody car the body will rust away to nothing before the engine so much as hiccups.

I'll probably save money with the petrol too*


(ignoring that all important depreciation, on the other hand the car I'm looking at is a bit special and rare thus it won't plummet in value like a middle management diesel in resale grey.)