A. Never had any difference unless your running the defroster, this runs the AC which of course will lower mileage.
Yes, the defroster was running constantly. In addition, the heater was running periodically.
B. This could be part of mileage cut. If stomping on the gas and driving over about 70 mph, this will reduce mileage. Was there headwind?
Yep, she does drive a little 'faster' than the average driver
C. What was the temp? I have only noticed a 3 mpg drop from a temp of 50 deg, to a temp of 20 deg. I am still averaging 52mpg in the 20 deg.
The temperature was about 40F.
D. I notice when I have a passenger in the car I loose 1 to 2 mpg on the round trip. But on a long trip of over 300 miles, there was really no difference. And this was on Interstate driving at no more then 65 mph. I also have had all the kids in the car. total of all of us would be about 630 LBS. I noticed again the 1 to 2 mpg difference.
Yes, two passengers.
I dont understand why your only getting 40 to 45 mpg. Are the majority of your trips less then 15 minutes long? (Other then this longer trip you have spoke of) This will also greatly reduce mileage. As the longer the car runs the more time it has to keep the optimal heating it requires to get the best mileage. You should notice this greatly in the summer time. I average 56 to 60 in 80 to 100 degree heat.
I haven't driven the car for long. It only has about 2000 miles on the clock so possibly it needs to be 'worn in' more? We do a lot of travelling of 15 minutes or less. Inflating the tires to 42/40 has improved the mileage. And we have never really driven the car for any length of time with NO luggage. Maybe its that low because we have had a sizable amount of luggage when we drive? Anyway, we'll see how it does over time.
A few other factors maybe, if your using cruise control or not, and also if your using the climate controls AUTO setting to allow the computer to decide how the car runs at its best, while keeping you happy while driving. Do you have any addons like ski racks or bike racks that change the aerodynamics of the car. Or even some have wanted to pull trailers with their car.
How much does cruise control get? I haven't really used it much yet. We don't have any racks or addons though we have travelled heavily laden which I spoke of earlier.
Thanks for the help.