GPF active cycles?

[monkeyhanger]

I'm surprised you can see such a significant fuel decrease as from what I understand no additional fuel is used to regenerate these petrol filters......the above posted vw document doesn't actually say how it regenerates but I did read on a Mercedes document that basically said the timing is retarded to generate an oxygen rich atmosphere to allow combustion to take place.

I'm surprised too. It seems to defy everything I think I know about GPF regen. I can't see why the car would want to run so rich as to cause a 33% drop in fuel economy while regenerating without a warning light on the dash. Maybe it was running mainly in port injection mode rather than DI mode (Polo GTI still has dual fuelling) and trying to get hot quicker with a rich mix? Doesn't make any sense to me as a  petrol exhaust (and therefore GPF) gets hot plenty quick anyway.

I can't fathom any reason for such a dive in mpg (temporarily), but the car did it while seemingly regenerating the GPF. Any ideas?

[monkeyhanger]

I had a facelift 2017 230ps DSG which farted and sooted up the tailpipes after only a week or so of driving. Guess if yours are soot-free then maybe has one.

Well I had a look under the bonnet at lunchtime, but because of the shrouding around the turbo, I couldn't really see much. Guess the only way to have a real look is with the car up  on ramps ?

If you have spotlessly clean exhaust tips and not as a result of a meticulous cleaning regime, I'm almost certain you'll have a GPF. Are you still doing huge mileage? If so then (unlikely), your exhaust is hot enough for long enough to be burning the soot off your exhaust - can't imagine the tips getting up to 550-600C to make this happen though.

[Sootchucker]

Short of DSG Sootchucker, that's a hell of a spec list on yours!!

Ahem..cough...it is DSG 

[Sootchucker]

If you have spotlessly clean exhaust tips and not as a result of a meticulous cleaning regime, I'm almost certain you'll have a GPF. Are you still doing huge mileage? If so then (unlikely), your exhaust is hot enough for long enough to be burning the soot off your exhaust - can't imagine the tips getting up to 550-600C to make this happen though.

Nah...I'm only doing just over 7k miles a year which is why I changed from the GTD to the GTI

[ajmoir36]

My 7.5 19 R revs higher on cold start and for longer than my 7 R 64 plate. I have also turned it off at home and thought why is the fan going. I do use sport mode manual downshifts all the time though to let the car slow down. The popping is addictive.

[dean5125]

Short of DSG Sootchucker, that's a hell of a spec list on yours!!

Ahem..cough...it is DSG 

  Oops.... I may have missed that

So was there any option box you didn't tick?!?!