Poor Fuel Economy related to Grass/Gravel/Snow?

[ChesapeakeRover]

So our area has gotten record amounts of snowfall in the recent week and I've been driving around permanently in Grass/Gravel/Snow and have noticed a severe drop in fuel economy. My normal lead footed 11 to 13 driving around town has dropped to 8 or 9!

Has anyone else used G/G/S and witnessed similar results or if not anyone think why this is happening, I have noticed the transmission waiting to upshift a bit longer but I usually just switch it over to command shift and up-shift myself.

Oh and here's some pictures of the snow :

 

[Trynian]

I would almost bet it is the gear shifting pattern and the fact that GGS starts out in second gear instead of first.

You are probably trying to compensate by giving more gas.

 

[ChesapeakeRover]

I found that the transmission was more eager to go from 2nd to 3rd but then stayed in 3rd for up to ~35 mph when it usually is in 5th by the then (driving conservatively with special programs off)

 

[Neild]

Yes, we've seen a 25% loss of MPG in GGS in the UK.

 

[BldrRover]

I have found that even without GGS selected, there is a loss of fuel economy in the snow due to the extra rolling resistance, extra weight on the roof and decreased aerodynamics (ice hanging off bumper...).

 

[Disco Mike]

Consider driving in another mode and see what works best for you. Yes, as you are driving it, it will get worse mileage.

 

[Neild]

Any also speed of people in lesser cars!!!

 

[roverman]

The gear mapping in GGS is bound to lessen your mpg a little, but 90% is because it's waaaay harder for a tire to roll through snow than on pavement. Plus, tell me you're not flooring it around snowy corners all the time.....

 

[ChesapeakeRover]

Plus, tell me you're not flooring it around snowy corners all the time.....

But seriously I've been trying to drive conservatively i.e. keeping it under 2000 rpm when shifting, but I think the added weight of the snow that's stuck in the rack plus the increased rolling resistance and programming of G/G/S would definitely negate my driving style. I came to the conclusion after my first post that the G/G/S would be permitting me to apply more gas from the get go like Trynian said, but didn't consider the rolling resistance at all. Very insightful, Thankfully the roads are better and I can switch back to general... until the next storm comes