Hi! Not sure where to ask this so I'm trying here, because I don't know if I'm dealing with a car that needs work, seasonal weather, route differences, or some cross-country headwind I don't know about. So, do people find that they get poorer mileage on east-to-west cross-country trips vs west-to-east, or fall/colder weather trips vs summer? I did and I'm very curious if this is unusual.
I drove a 2009 Honda Fit stick shift, with around 24000 to 29000 miles from first to last cross-country mile, in both directions between Sacramento, CA and Madison, WI. Both times there were two passengers and the same amount of stuff in the trunk and back seat and the driver stuck faithfully to speed limits. The car was driven only a couple hundred miles in between the two long trips.
Eastbound: Late May, lots of air conditioning. 80 to Salt Lake, then a detour to Moab via 191, then 70 to 76 back to 80 in western Nebraska -- same jag up through Iowa to Madison. Car killed it going through those mountain passes in western Colorado. Average mpg = 42.
Westbound: Early November, just a little bit of heat for the evening hours. 151 to 30, then 80 all the way from Des Moines. Very few off-highway jags of no more than a few miles. Average mpg = 39.5, and that was only after coasting down the last stretch of 80 -- up until Salt Lake, it was down to 37.5 and only slowly crept back up until the Donner Pass. Car did not kill it at all.
Any ideas from folks more familiar with road-tripping than myself (or suggestions of where to ask this if I'm in the wrong place)? I would've thought the air-con would make the summer trip worse, but maybe the engine really didn't like the cold? Or maybe the mountainous Colorado route made up for the air-con by allowing even more coasting than I could do through the milder passes in Wyoming? So puzzled. The only other thing I can think of is if maybe the speed limits on the southern Utah/Colorado detour were lower enough to make a difference over the average.