Volkswagen's Diesel Emissions Fix Lowers Fuel Economy, Claims Real-World Test

Volkswagen was probably hoping that the dust from dieselgate was beginning to settle, but a new test by a British magazine has suggested that the emissions fix is actually lowering people's fuel economy
Volkswagen's Diesel Emissions Fix Lowers Fuel Economy, Claims Real-World Test

Volkswagen’s diesel engines are delivering worse fuel economy because of the dieselgate fix applied to them, suggests an Autocar test.

Autocar compared the economy results of a pre-dieselgate 1.6 TDI VW Touran MPV to its own new figures using a ‘fixed’ 2013 car, with both tests run to the True MPG standard of its sister title, What Car?, at Millbrook Proving Ground. The programme is meant to closely match average real-world driving patterns.

The old Polo Bluemotion's 1.2 TDI is involved
The old Polo Bluemotion's 1.2 TDI is involved

Volkswagen has insisted that the fix has no impact on the fuel economy of those engines that receive it, but the weekly magazine saw a drop of over 3mpg, from 50.72mpg to 47.61mpg. The test, they say, is repeatable to within 1 per cent accuracy and typically accurate to within 0.5 per cent, giving a maximum theoretical 1mpg overall margin for error between the two numbers, but a 0.5mpg margin is likelier.

Over the single test the nitrous oxide (NOx) readings were almost halved, from 0.639g/km to 0.351g/km, suggesting the fix has at least done what it was supposed to do, but Autocar says that an average from three repeated test runs would be more accurate.

This is not the first report of trouble with ‘fixed’ engines, with others already having reported breakdowns and myriad new faults.

Diesel Golfs are also affected
Diesel Golfs are also affected

It’s fair to say Volkswagen disputes the findings, saying that there are more than 20 variables that could have affected the outcome of the test, although it refused to define those more specifically.

The 1.6 TDI engine in the Touran is one of three affected by the dieselgate saga; the other two being the 1.2 TDI in the Polo and the 2.0 TDI found in just about every mid- and large-sized car the Volkswagen Group makes.

In total there are 750 combinations of affected drivetrain and car, says Autocar, and that means VW has had to develop 750 different fixes. There’s no suggestion that this test means all of them must be negatively affecting fuel economy, but the question is inevitably going to hang there until someone tests every last one.

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Comments

BV86_OFISHAL (AUDM Fanboy)

i got some photos of the mk10 golf…

05/17/2017 - 11:52 |
142 | 8

Probably will look exactly like the Golf 7

05/17/2017 - 12:22 |
22 | 2
Joshua Persaud (Wagon/Estate Squad) (Sleeper Squad) I need a

In reply to by BV86_OFISHAL (…

Thomas the Dank Train intensifies

05/17/2017 - 22:18 |
0 | 4

Why must we bend over for the big government overlords. They screw up everything they touch. The tdi was a wonderful engine.

05/18/2017 - 00:53 |
6 | 0
Mark Mason

3mpg? Who cares?

05/17/2017 - 12:00 |
20 | 10

If you do a tank a week at 18 gallons that ‘s 936 gallons per year. At 25 miles per gallon, that’s 23,400 miles. At 28 mpg it’s 26,208.

Call it 3000 miles per year differance.

3000 divided by 25 = 120 gallons.

3000 divided by 28 = 107 gallons.

13 gallons at my price here of three bucks per gallon is…. $39 extra per year.

In the UK a gallon of diesel is 5.49 quid. That’s going to be 71 quid a year extra, but people that use diesel tend to drive higher miles than most.

Someone should probably check that… it’s late and I’m too tired to math.

05/17/2017 - 12:18 |
36 | 2

Matter of principle, really. Imagine the following scenario:

Spend £20,000+ on new car.
Suddenly find out your car doesn’t meet emissions levels, as advertised at time of purchase.
Months later, you finally receive notice for a recall to ‘fix’ the ‘fault’, or in this case, ‘lie’.
Get car back from being ‘fixed’ by manufacturer, only to notice this has now had a detrimental effect on economy.
You’ve now been lied to by said manufacturer twice, and can do sweet FA about it.

I’d be pretty pissed off.

05/17/2017 - 16:16 |
10 | 4
Anonymous

VW should replace the Bluemotion badge with a Dieselgate Special Edition badge.
That’ll bring the price up.
..

.
NAHT.

05/17/2017 - 12:01 |
22 | 8
Josh A.
05/17/2017 - 12:10 |
12 | 14
FUGL_S60 (Tesla Lover 800)

In reply to by Josh A.

Oh….that’s old…how I loved making fun of VW over this scandal!

05/17/2017 - 23:33 |
2 | 2
Tomislav Celić

My dad has a 2016 Golf 1.6 TDi. And we get between 3.7 (open road) and 7 (city) l/100km.
So combined it’s around 5.2l/100km. You calculate to your MPG

05/17/2017 - 12:21 |
6 | 0
Anonymous

Hey look, they cheating again

05/17/2017 - 12:27 |
2 | 6
Anonymous

It’s as if putting restrictive equipment on what is essentially an air compressor reduces its ability to move air. Who would’ve thought.

05/17/2017 - 12:27 |
12 | 0
TheMindGarage

Good thing my parents traded in their Touran :D

05/17/2017 - 14:09 |
4 | 2
Anonymous

I have covered 14k in my car (a 2ltr Skoda superb) since the update and the average fuel consumption has improved by about 6.%. I use fuelly and kept accurate records of miles driven and fuel uplifts. No noticeable difference in power and the car is running perfectly. Methinks autocar is just trying to find some negative news. Sad but good news is not interesting. More than happy with the fix.

05/17/2017 - 18:46 |
6 | 0
Anonymous

I really miss my tdi with the dsg. Leave the cars alone and fix the EPA and our overbearing government masters.

05/18/2017 - 00:49 |
4 | 0