MK7 GTD - Real Life MPG

[corgi]

Also, the Scirocco is more Aerodynamic than the Golf, I suspect not massively so, but might make a 1 or 2 mph difference on my roadsign marker test, as might a strong headwind as opposed to no wind or a strong tail wind.

It might well be more aerodynamic with a smaller frontal area but will that offset the apparent power:weight advantage of the Golf?

I purposely hadn't factored in wind direction and strength, because, again they are unknowns

As I said, I suspect you'll never know whether your Scirocco was a good one and your Golf average...

[monkeyhanger]

Corgi: my Golf is 10kg heavier than my Scirocco, those 2 extra doors negate the weight savings, not that 10kg is going to do a lot either way. Too many variables - hoping V-power has been the achilles heel to date.

[Sootchucker]

For the diesel version at least, V-power's likely gains are from your car running cleaner because it is a purer fuel. It used to be pure GTL content (apart from the additives, and now it is a blend of oil derived diesel and GTL derived diesel. V-power is less dense than normal diesel, because the GTL derived part has shorter average hydrocarbon chains than the oil derived part. Basically it has less hydrocarbon content and therefore less chemical energy than standard diesel. If it can burn more completely than standard diesel then there could be no disadvantage, but as people running normal aren't being inundated with regens then i'd say standard is combusting just fine in the GTD. Lower Cetane rating with V-power (52) than Shell's standard (56), should mean that standard has a head start in combustion.

And you call us for being boffins.......wow, most of that went straight over my head     

[monkeyhanger]

Norbreck21: I put in a lot of thought about some things - that very expensive lump of metal parked outside my house is getting most of my thoughts right now! 

Maybe I could upgrade it to a Lambo if only I used my Chemistry knowledge a bit more constructively, something along the lines of "Breaking Bad". 

[mcmaddy]

I was out on Sunday for a couple of hours with a mix of motorway and a roads and believe it or not the car decided to regen just as I pulled up outside the house and that's using normal shell. I didn't see more than 1regen when I used the vpower diesel but have had three already using normal stuff.

[monkeyhanger]

I was out on Sunday for a couple of hours with a mix of motorway and a roads and believe it or not the car decided to regen just as I pulled up outside the house and that's using normal shell. I didn't see more than 1regen when I used the vpower diesel but have had three already using normal stuff.

How’s your mpg though on the normal stuff? Better than with V-power I hope.

I do wonder whether V-power has a cleaner burn because there is less combustible product per litre to burn (because it has a lower density), and because of that it doesn’t need a high Cetane number to completely (or nearly completely) combust.

Although saying that, I have had 2 regen attempts recently on 100% V-power, maybe it’s the colder mornings making the car take longer to warm up and work at its most efficient.

Sometimes regens seem to start at the end of a journey for me – quite inconvenient when you pull up and the car is making a racket because the fans are going full tilt to cool the car.

[mike_f]

I emailed VW to ask what kind of fuel performance I should be expecting for the type of driving I do...

Also speaking to one of the guys at work who said his daughter has a Mk6 GTD and can easy get high 50s on a motorway run.

Given the Mk7 car is boasting economy figures about 10mpg higher then I would expect it to mean the mk7 should be capable of this or it means the figures are absolutely pointless ion every way.

[monkeyhanger]

I notice on the TV adverts for the new Audi A3 E-tron Sportback (due out Autumn 2014), they have prominent messaging to say that the quoted economy figures are for comparison purposes with other car manufacturers only and standard EU tests may not represent actual driving conditions.

Seems pretty clear to me from a VAG company that we shouldn’t be expecting anywhere near published figures….ever. Anything better than the last gen is to be taken as a bonus it seems.

[monkeyhanger]

I hoofed it to work today, and despite it being a chilly 6C, I think there might be something in driving the car a little harder to get it warmed up (and more efficient) quicker. Got an indicated 47.2mpg, which is probably still only around 42.5 – 44mpg actual, considering I have the box back on at setting 4. I have recently averaged 42.5mpg actual when I have not been putting my foot down.

[andyk11]

One of the VW sales guys had his own Scirocco 177 tdi and reckoned it took 3000 miles to eventually loosen up and really get going.  Maybe the low friction bearings in the latest VAG engines take more time to bed in...?

That's interesting, my GTD has just reached 3000 miles and it feels much more urgent.  I'd previously commented on how it felt a bit flat in 5th and 6th... it's got hugely better recently and now pulls like I'd expect it to.

From new the engine has always been smooth and willing to rev but now it's got the grunt to go with it 

I had been running BP Ultimate for a few tanks but can't say I noticed an improvement in performance or economy.  My previous cars have always run noticeably better on BP Ultimate (albeit with no measurable improvement in economy).  I'll probably give it a go again to see if I can notice a difference now.

Economy wise it's been consistent since new (I generally do the same journeys each week) -

449m 47.9mpg (47.9)
462m 48.8mpg (50.4)
502m 49.7mpg (50.6)
433m 47.3mpg (52.6)
423m 47.9mpg (48.7)
509m 48.6mpg (50.9)

The number in () is the indicated MPG whilst the other is actual measured brim-to-brim.  Most of my journeys are on the motorway sitting at 75-80mph and some slow city centre traffic.