Originally Posted by mikemc

I've been using a ScanGuage with my Honda Accord Hybrid the last several weeks. Attached is an Excel file of just a few days of data I recorded with it. With the cold weather, some of the fuel savings features such as "auto stop" don't kick in until I'm almost done with my 6 mile drive to/from work. With the ScanGuage, I can see the instantaneous mileage, fuel flow rate, and other metrics. With regard to the instantaneous mileage, small variations in throttle position can result in major differences in mileage. With regard to the fuel flow rate, in 10 degree F weather the idle fuel flow starts out at about 1.2 gallons per hour. Once the engine is fully warmed up (after about 10-13 minutes of driving), the fuel flow at idle drops to around .2 to .3 gallons per hour. Thus, very short trips in cold weather result in poor mileage. On the one day with relatively warm weather (60 degree F) shown in my data, my mileage shot up significantly.