We all know the hype that's surrounded both cars and their "claimed" MPG figures which are vastly improved over the outgoing models, which again we all know are not really achievable in real life, but are more for comparisons purposes.
I did have a thought though. As both cars in Germany come "standard" with 17" alloys (with our UK standard fit 18"s being a cost option), I assume the figures produced are done with the smaller wheels ? That being the case, how much do you think the 18's will wipe off the claimed figures ?
I don’t think it’ll have any effect at all – the 17” wheels are just as wide as the 18” Nogaros and Austins at 225mm.
Whatever the computer indicates, you can knock 9% off it for actuals. Using the brim filling method, my Scirocco 170TDI averaged 49.8mpg on it's last tankful according to the computer, but just 45.4mpg in terms of miles covered vs actual fuel consumed.
My dad’s GTD DSG 5 door officially does 60.1mpg combined. On his last tankful at approx. 900 miles in, it indicated 47mpg but actually did 39mpg. I know it has a bit of running in yet, but with VW’s universal engine improvements touted for the MK7 variants including reduced friction surfaces, I don’t think we’ll see much in the way of “running in” gains.
Lets be clear though, my dad’s driving style is very uneconomical – he will cruise on the motorway at 85-90mph if he can get away with it (if others are doing more than that, so he doesn’t “stick out”). He’s got all the toys on and doing their thing. If I had his car right now, the way I would drive it, I would expect to outdo his economy by 10-15%. Either way, compared to his old MK5 GT 170TDI, it appears to be approx. 10% down on economy right now (and driven the same way). Driving the car straight back from Newcastle to Southampton is not the way I’d like to run my car in either, with the first 350 miles pretty much cruising on the motorway. He’s also had the aircon on permanently since getting it.
GTD’s (and all MK7 TDIs) biggest claim to increased fuel economy that is not seen on the TSIs are revisions made to the integrated exhaust manifold set-up to quicken the warming of the engine to normal operating temperature. These will help economy on shorter runs a lot (and the effect will be prominently seen on the official urban and extra urban testing cycles), but on a long motorway journey, poor economy at the start of the journey has a negligible effect on the trip as a whole.
I hope to crack an indicated 55mpg minimum around the doors with my GTD manual as a reasonable starting point. 10% gains on the outgoing models seem far more likely than VWs touted 20%.
I do think that all those toys will have a detrimental effect on fuel economy – especially if ADC is subtly braking for you a lot if you like to drive closer to the car in front than the system would like you to. I’m used to getting very close to official combined figures on my commute and easily exceeding it on longer journeys, all without driving like a nun – I don’t think I’ll manage it this time.
I think VW may have stretched the truth a bit too much this time and test conditions are further away from real driving conditions than ever.
Those “up to 100kg weight savings” are largely nuts. Unless you’re driving a 120PS or less variant with the simplified rear suspension, you’re unlikely to see more than 35-40kg weight savings. 23kg lost from the body shell and 5kg lost from the smaller capacity fuel tank (which is 90% full for the purposes of VWs testing).
