I have been driving in -10 C weather since I bought my vehicle in December 05 and this is what I notice:

All ICE (excepting Assist and regeneration) features are delayed for about 5 minutes until the engine warms up and the heat begins to flow... furthmore this past three days the temperature has been -15 to -20 Celcius and during this cold temperature snap the autostop feature does not work and the FE glide will not engage.

I found that I am averaging 6.2 L/100 KM without the auto stop and FE Glide during the harsher cold weather and averaging 5.7 L - 5.9 L during the -10 Celcius weather so as you can see the cold is definately a factor.

Having said that when the temperature is above 0 Freezing (I have had a few days like this) the mileage is phenomenal .. between 4.9 and 5.5 L/100 KM.

If you look through the tank log database you will see this very evident. The HyperMilers and those acheiving less than 5.0 L/100KM are enjoying 20C+ weather and I look forward to acheiving these numbers in the spring and summer months.

Hope this helps and Cheers!

Filled up tonight...MPG was down to a "horrible" 39.8 MPG. This despite most of the driving during this tank occuring between -5F to +20F. Still twice the Odyssey and nearly 3X the Sub. So this sub-freezing weather has cost me about 10%. I guess I'll have to get rid of this gas guzzler.

Going skiing at Winter Park on Monday. Since we're bringing some of my son's friends, we're taking the Ody and either the Sub or the Civic depending on how much equipment we bring (no ski racks for the Sub or Ody). It will be the first time going through the mountains and up some pretty long, steep climbs. I'm sure I'll be running the battery all the way down going over the Continental Divide and a few other hills.

2005 Honda Odyssey EX-L RES & NAV - Desert Rock Metallic

2006 Honda Civic Hybrid NAV - Magnetic Pearl

2007 Toyota FJ Cruiser - Black Cherry (First Toyota, Third non-Honda)