-7 tonight, how low can diesel go?

Reedy · 19 Jan 2013 at 19:32

act smiley said:
I presume they add some extra additives for winter even in the UK, but I'm not sure how much difference it makes?

I know Germany (among other places) have "Winter Diesel"

delta0 · 19 Jan 2013 at 19:38

Winter diesel won't cloud or gel until a lower temperature. UK uses winter diesel.

DannyW · 19 Jan 2013 at 19:39

bit off topic but does anyone know why these last couple of really cold weeks my mph has gone from 44mpg to 38mpg doing the exact same trips

delta0 · 19 Jan 2013 at 19:41

DannyW said:
bit off topic but does anyone know why these last couple of really cold weeks my mph has gone from 44mpg to 38mpg doing the exact same trips

Air is denser and therefore more fuel is added to maintain the correct fuel to air ratio. If it is a petrol then you have the extra effect of longer warm up period where more fuel is added as well.

DannyW · 19 Jan 2013 at 19:44

delta0 said:
Air is denser and therefore more fuel is added to maintain the correct fuel to air ratio. If it is a petrol then you have the extra effect of longer warm up period where more fuel is added as well.

its diesel

delta0 · 19 Jan 2013 at 20:02

DannyW said:
its diesel

You just have the denser air effect then. Air density changes with temperature. Colder temperature means the air is denser. This means more air is entering the engine. In order to maintain the correct air fuel ratio, more fuel is added.

ianh · 19 Jan 2013 at 20:05

DannyW - It's still what Delta0 said -

delta0 said:
Air is denser and therefore more fuel is added to maintain the correct fuel to air ratio.

I'm a Diesel owner too and seen about the same MPG drop off and the Mondeo forum I'm onn has lots of threads about the same thing. In the cold your MPG will drop, Ford gave a figure of 12-15% IIRC at temps of 5'c or lower (colder the temp the lower the MPG).

paradigm · 19 Jan 2013 at 20:19

Left my 330d for over a week at under -20ºc in the alps and had a little trouble (ran rough for a minute or two) starting.

We won't get anything cold enough to cause problems.

iaind · 19 Jan 2013 at 20:30

Jesus you'd think it was "the day after tomorrow", as most are saying just get on with it.

The odds of the temperature outside getting that low are slim. The odds of the fuel in the tank getting to that temperature are even slimmer. The odds of it causing a problem are zero

brucey034 · 19 Jan 2013 at 20:33

delta0 said:
Air is denser and therefore more fuel is added to maintain the correct fuel to air ratio. If it is a petrol then you have the extra effect of longer warm up period where more fuel is added as well.

Petrol engines warm up quicker than diesel engines in my experience.

ianh · 19 Jan 2013 at 20:35

I think he meant longer than usual, not longer than a diesel.

brucey034 · 19 Jan 2013 at 20:36

ianh said:
I think he meant longer than usual, not longer than a diesel.

Ah ok my bad.

Locky · 19 Jan 2013 at 21:11

When we had that REALLY cold snap a few years back -20? the derv went bad in the plant we where using on site (got me the day off

)

Matt82 · 19 Jan 2013 at 21:27

this is a tdi

delta0 · 19 Jan 2013 at 21:29

brucey034 said:
Petrol engines warm up quicker than diesel engines in my experience.

Yes they do. However during the warm up period a petrol engine will add more fuel. When the temperature is low then this takes longer. For a diesel the injection timing advances but no more fuel is used during cold weather. Diesel does take longer to warm up regardless of temperature.

brucey034 · 19 Jan 2013 at 22:33

delta0 said:
Yes they do. However during the warm up period a petrol engine will add more fuel. When the temperature is low then this takes longer. For a diesel the injection timing advances but no more fuel is used during cold weather. Diesel does take longer to warm up regardless of temperature.

Good to know.
At least I will be warmer quicker now than when we had our 1.9 tdi golf
The golf took forever for the heater to get warm.

paradigm · 19 Jan 2013 at 22:51

brucey034 said:
Good to know.
At least I will be warmer quicker now than when we had our 1.9 tdi golf
The golf took forever for the heater to get warm.

Whereas the cabin will be warmer far quicker in my diesel thanks to it's aux heater.

iaind · 19 Jan 2013 at 23:00

paradigm said:
Whereas the cabin will be warmer far quicker in my diesel thanks to it's aux heater.

Likewise. If I could ever figure out the right combination of circumstances, button presses and voodoo required to get it going

paradigm · 19 Jan 2013 at 23:24

MMI Car Menu > Heating > Use Aux Heater = Auto

sneakypenguin · 20 Jan 2013 at 00:10

Matt82 said:
this is a tdi

this is gay