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Yes!

I've noticed it mainly occurs when warm and release the accelerator and roll. With the radio off and on fan setting 2 you can hear the fan speed up and slow down.

Wipers aren't so easy to catch, but they definitely seem to be faster some times.

Muldoon wrote:

Adam_013 wrote: Wed Dec 05, 2018 12:52 pm Yeah, especially coming from a previous polo and never having this issue with Aircon.

Then again I never had the fan speed issue either - which I'm assuming is smart charging stuffs.

Andy Beats wrote: So you think the aircon is on restricted performance or even off altogether, even though the light is on?
That would certainly explain the poor demisting.
Disappointing when I've not seen the same drop in aircon dehumidifying performance from any other make.

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Adam - you mentioned fan speed issues and smart charging - would this be a perceived change in fan speed / noise? I have noticed the wipers go slow and then speed up (thought it was my imagination at first) - could this be some device to save energy and vary the voltage going to different equipment?

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Hi

Just an update - the 1.0 TSI engine is an odd set up re warming up - my communte is mainly down hill and low engine load, only a bit uphill at the start then around 3 miles 30mph but not working the engine. The temperature gauge remains at the bottom on 50 degrees all the way until I park up. It only shifts if you give the engine some work to do and accelerate then it quickly moves up to 90 and stays there.
Never had this in any previous cars, they all warmed up regardless of gentle driving or almost coasting downhill. It must be some kind of efficiency device but not helpful to get the car warm in winter.

In petrol engine development it seems that at least for VW Group, they moved on past the point where auxiliary heater should have been fitted to the cabin air box for cars being sold in UK and some other territories when the 1.2TSI EA211 engines were launched, but maybe cost savings came before driver safety/convenience?

Yes an auxiliary heater will use some power, but it will only be operating as and when the lack of heat being dumped from the engine coolant system requires it to.

They're setting up engines to run so lean these days, they're almost always the verge of pinking/misfiring.
You can feel it sometimes, they just feel like a car running lean as hell.
That affects warm-up, the less fuel, the less flame, the less heat.
In t'olden days you'd have richened the mixture manually using the choke.
The ECU will have a cold running setting, like a choke, but it'll still be running as lean as lean can be.
Arguably better to run it rich and warm it up quicker, but it's not very green to have petrol fumes spewing out the back of your car every morning.

In another forum I'm in, some members who fill-up with supermarket fuel complain that their engines sounds as though their pinking. OK purchasing cheaper fuel if monies tight, but I don't care what people say that it all comes out of the same tanker?
When you purchase branded fuel (Shell, Esso) it's got better cleaning properties and gives the correct grade of fuel including additives, than supermarket fuel.

One thing with the old manual choke, it did higher the revs of the engine, so enabling the engine to warm up faster.

silverhairs wrote: Wed Dec 12, 2018 12:16 pm In another forum I'm in, some members who fill-up with supermarket fuel complain that their engines sounds as though their pinking. OK purchasing cheaper fuel if monies tight, but I don't care what people say that it all comes out of the same tanker?
When you purchase branded fuel (Shell, Esso) it's got better cleaning properties and gives the correct grade of fuel including additives, than supermarket fuel.

It's all the same fuel when it goes INTO the tanker at the refinery.
But the drivers are issued with 'additive packs' that differ depending on where the fuel is being delivered.
So, yes, the cheaper petrol does have different additives than the petrol station stuff.

Andy Beats wrote: Wed Dec 12, 2018 1:33 pm

silverhairs wrote: Wed Dec 12, 2018 12:16 pm In another forum I'm in, some members who fill-up with supermarket fuel complain that their engines sounds as though their pinking. OK purchasing cheaper fuel if monies tight, but I don't care what people say that it all comes out of the same tanker?
When you purchase branded fuel (Shell, Esso) it's got better cleaning properties and gives the correct grade of fuel including additives, than supermarket fuel.

It's all the same fuel when it goes INTO the tanker at the refinery.
But the drivers are issued with 'additive packs' that differ depending on where the fuel is being delivered.
So, yes, the cheaper petrol does have different additives than the petrol station stuff.

Additives are the key. Higher octane petrol isn't appreciably more fuel dense, but the additives make it less volatile, so it can be compressed further without auto-igniting (pinking) - petrol cars meant to take higher octane fuels have a higher compression ratio. Similarly, in an exact opposite kind of way, Premium diesels get cetane boosters to increase Cetane number and make them more volatile for a cleaner burn. Diesel is compressed further than petrol and runs on autoignition - bigger squeeze =bigger bang = better efficiency. Diesel only 8% more energy rich than petrol yet gives 30-50% more mpg. Technology for petrols recently has been towards having them run more like diesels with higher compression.

The premium fuel gets a more generous helping of detergents too.

I know all about high compression, additives and pre-ignition etc.
When I raced two-stroke bikes, we used to buy stuff called Toluene to add to petrol so that we could run as high compression as possible without pre-ignition.
Or AVGAS, if you could get it.
Many a trip from Aberdeen to a North of England circuit would be broken with a trip to a flying club for fuel.
Easy enough to whip the head off a two-stroke and see the 'pock marks' of pre-ignition on the combustion chamber dome.