MK7 GTD - Real Life MPG

[2014GTi]

Gulp... I guess my Polo Bluemotion is a different engine, it took at least 20k miles in that before I saw good mpg figures. Was easily getting 65-75mpg without much effort.

I am really surprised at my GTi mpg considering its not even reach 2000 miles yet, wasnt expectng to see 40mpg + at such a early stage of the engines life. Thats not that much worse than your dads GTD figures 

Maybe these new GTD engines are like me Polo where it needs a good 20k miles before mpg improves?

I do a relative long but smooth trip into the office, its 44 miles with 65-75% M1 motorway and the rest normal urban roads. 

[mike_f]

Do you think car manufacturers are perhaps optimising their vehicles to cruise through EC testing and emission testing rather for better marketing than building cars which are genuinely most economical for the 95% of us who drive the way we do.

Perhaps rather cynical but would appear that way to me..

[monkeyhanger]

Gulp... I guess my Polo Bluemotion is a different engine, it took at least 20k miles in that before I saw good mpg figures. Was easily getting 65-75mpg without much effort.

I am really surprised at my GTi mpg considering its not even reach 2000 miles yet, wasnt expectng to see 40mpg + at such a early stage of the engines life. Thats not that much worse than your dads GTD figures 

Maybe these new GTD engines are like me Polo where it needs a good 20k miles before mpg improves?

I do a relative long but smooth trip into the office, its 44 miles with 65-75% M1 motorway and the rest normal urban roads. 

44 miles (is that each way?) commute with 65-75% on the motorway isn't typical for most. If I drove 44 miles every day with most on the motorway, I wouldn't expect to ever get an active regen (which pushes my tank average down by 2mpg), and i'd expect to get 53mpg from the GTD (and 40mpg from the GTI doesn't seem beyond the realms of possibility in those circumstances), as I have seen 51mpg on a slightly longer commute (16 miles as opposed to 12 miles). Same circumstances would have yielded 56mpg min in my 170TDI Scirocco.

Different people on different routes/different commuting lengths/different driving styles are going to get different results, although patterns do emerge - people on longer commutes see bigger mpg results, with optimum for GTD being >15 mile trips. Side by side though, for my driving circumstances (which haven't changed for my last 4 cars), the GTD is 10% worse than my Scirocco, takes up a far bigger proportion of my commute to warm up and suffers far more regens as a result - both of which affect mpg negatively.

The fact that pretty much all the MK7 Golf engines from the 1.2 and upwards) have "seen" 20% alleged increase in combined mpg seems to lend credence that the biggest change for the MK7 is moving of the testing goalposts for mpg. Far more of the current testing method has the car sitting idle than the old method, meaning that the inclusion of stop-start tech reduces fuel consumption significantly on the new test, hence the "improvement".

[monkeyhanger]

Do you think car manufacturers are perhaps optimising their vehicles to cruise through EC testing and emission testing rather for better marketing than building cars which are genuinely most economical for the 95% of us who drive the way we do.

Perhaps rather cynical but would appear that way to me..

That is exactly what they are doing, all of the manufacturers are doing it - is it coincidence that all the manufacturers just got 20% better in fuel economy or have the goalposts changed?

Last gen VWs had a combined mpg result easily achievable on all but the shortest journeys and you didn't have to drive like a nun to get there.

Is it any wonder that only in the last year the car companies have arse covering messages in their adverts - "67mpg combined....figures quoted are for comparison between car brands only and may not reflect real driving experiences". They never had to do that before to save getting sued wholesale.

All this does for the consumer is give them false mpg hopes and cheaper car tax - surprised the DVLA haven't jumped all over the car companies false claims for lost revenue. I'm sure all car emissions bands will be re-categorised before long so that only the bottom 10% of all cars get free car tax, and the next 10% get £20/30 tax discs.

[2014GTi]

I agree with the comments regarding the way mpg figures are calculated but I dont think the EU standard has changed for a while. Which means you should see the improvments between the previous generation and the new. 
Manufacturers use technology like stop-start, DSG coasting and Brake regen to boost their mpg figures but exploiting the EU test weaknesses.
All the EU test cycle is done on a rolling road too 
The EU mpg testing is changing in 2015 I believe to give a more real-world reperesentation for consumers, you have to remember all the manufacturers are using the same EU testing cycle, so comparing car mpg A vs B is still true.

I do 44 miles one way to the office, it takes 1hr 5minutes on a good day and so far I have only done a weeks worth of travel in my GTi, Monday so 37.5mpg, every other day was 40mpg +
I am expecting between 5-10mpg increase once the engine has opened up, this is based on how my Polo opened up at 20k miles... I saw a minimum of 10mpg extra since new on the Polo. 

Even if my GTi only ever peaks at just over 40mpg thats good going, I'm not doing anything silly like 60-65mph etc.
Based on my commute to work and drive style, compring it to the GTi, a GTD should return 60mpg if I had bought one. 

[Pob17]

Interestingly, on the MK6 GTD threads, someone does state that since their Bridgestones wore out and the replaced them, their fuel economy improved by 10%. That does seem incredible - 10% economy gains from a change in tyres - can rolling resistance differences between tyres make such a significant difference? I was expecting 3% gains at best from better tyres. Perhaps if VW spent an extra £20 per car they might've had most of us here scraping at least 50mpg on most journeys if there are 10% gains to be had.
[/quote]

Absolutely... when Kwik Fit threw some own brand junk on my company car the economy dropped from an average 48-50mpg to sub 40mpg overnight. I stuck with it for a week before phoning the lease company and insisting they put GoodYear Efficientgrips back on. Funnily enough the economy returned to 48-50mpg straight away... Driving 30,000 miles a year it would have cost a fortune!

[2014GTi]

Yes tyres can make a massive difference, even incorrectly inflated ones... I used see mpg improve upto 3mpg when my tyres were correctly inflated.
So perhaps this is why many are seeing poor mpg figures, every single car does not go through a EU mpg test, the EU mpg certification would have been done early on in the cars release and once approved tyre suppliers could have changed etc. 

[monkeyhanger]

http://en.wikipedia.org/wiki/New_European_Driving_Cycle

On the current testing cycle, 31% of the urban testing cycle is at a standstill, 10% of extra-urban is at a standstill, combined calculation puts 24% of the car's journey time at a standstill. Pre-fitment of stop-start tech, that meant 24% of the testing cycle performed with the car at idle compared to 24% with the engine off on stop-start tech fitted.

Cycle beating optimisations that do not help consumers real world driving can also take advantage:-


The fixed speeds, gear shift points and accelerations of the NEDC offer possibilities for manufacturers to engage in what was called 'cycle beating' to optimise engine emission performance to the corresponding operating points of the test cycle, while emissions from typical driving conditions would be much higher than expected, undermining the standards and public health. In one particular instance, research from two German technology institutes found that for diesel cars no 'real' NOx reductions have been achieved after 13 years of stricter standards.

I think most of the "20%" efficiency gains can be seen from the above info.

I would be amazed if a run in MK7 GTI/GTD is 20% more efficient at 20k miles than 0 miles due to running in - you would also expect incremental power gains to similar values (a 264PS stock GTI after running in?).

20% is a massive incremental mpg gain (unless you compare worst winter figs with best summer figs). I would be amazed to see that for any engine, Far more likely to see a modest gain within first 500 miles as things loosen from manufacture/assembly, tyres scrub in etc. Swapping out old tyres with crap rolling resistance for better ones at 15-20k miles when the fronts wear out can give 5% efficiency overnight, nowt to do with the mechanicals.

[monkeyhanger]

My tyre pressures are checked weekly and are at the approved pressures as per the fuel flap sticker.

[mike_f]

you have to remember all the manufacturers are using the same EU testing cycle, so comparing car mpg A vs B is still true.

Not so - I made a decision in March of this year to not buy a Mk6 but hold of for the Mk7 based on the comparative 10% improvement in fuel economy..

In fact it has proven to be 10% worse so the EC figures are absolutely meaningless...

I wouldn't even support VWs caveat that they are for comparison only as there is no direct relationship between the MPG figures between the MK6 and Mk7 and the actual real world results most people are getting..