Chilly week - mpg's affected???

**kunaalv** · 19-11-2010,08:30 PM

Hey,
As it's been very chilly this week in the UK, y mpg's have decreased by about 6mpgs? Can the cold really do this?

Passat - 2.0 TDi

**reallyfree** · 19-11-2010,10:08 PM

Yes me too. Last winter I thought something was wrong with the car only to see it gradually improve as weather improved. I am sure I remember from college days that the internal combustion engine is at its most efficient when the air temperature is low. Maybe thats just petrol engines. Of course it wasnt that long ago we had to mix petrol with diesel in winter just to keep the dam thing going!

**fat controller** · 19-11-2010,11:25 PM

Sitting defrosting and demisting the windows of a morning is destroying my MPG, but I'm not a fan of de-icer fluids and stuff for the sake of my paint.

**logiclee** · 20-11-2010,01:01 PM

Lights on more, heated seats, heater blower, heated screens and mirrors, glow plugs and most importantly increased warm up times.

I've dropped around 6mpg from what I was getting August/September on the same route.

Cheers
Lee

**mikecb1** · 20-11-2010,01:21 PM

I've also read that "winter" diesel fuel has added antifreeze ingredients, one side-effect of which is to reduce mpg.

Mike

DSG4ME · 20-11-2010,02:01 PM

Most of it comes from battery drain, you use the wipers,light's,heater and heated rear screen more, this results in the alternator working harder off the engine to keep the battery charged, the other is the cold start takes longer to warm up, and you are also going to find the engine cools down quicker when it's off, so stopping for an hour is going to require the choke to activate more often, where in the heat it will be off quicker as the lump won't have shed all the heat from it's last run, hth.

**Zeb** · 20-11-2010,02:07 PM

Since the cold weather has started, the mpg has dropped by a longshot! I was getting above 45 mpg on the motorway, but now I'm getting around 41 - 44mpg!

**rapport25** · 20-11-2010,02:27 PM

Please see my thread and add your daily mpg.

Rappy

https://www.vwaudiforum.co.uk/forum/s...=109157&page=6

**rapport25** · 20-11-2010,02:29 PM

Originally Posted by fat controller

Sitting defrosting and demisting the windows of a morning is destroying my MPG, but I'm not a fan of de-icer fluids and stuff for the sake of my paint.

I have never used either. My method is fill the kettle with cold water from the tap and add a drop of warm.

Works everytime