I've been keeping a daily log of my trips to & from work for about a month now. I don't have a Scangauge or anything like that, so I'm just using the factory installed trip mpg. I know it reads ~10% high, but I trust that it's at least directionally correct. Anyway, I've heard people talking about how temperature and other conditions affect mileage so I thought I would look at my data. I look at the records from a local weather station (from
Welcome to Weather Underground : Weather Underground--not to be confused with the political organization) and record the temperature, pressure, humidity, & wind speed/direction. I thought others might be interested in the data.
FYI, I'm running a intercooled turbodiesel (with a variable-geometry turbo), so I am NOT implying that these results are generalizable. My commute is about 40 miles each way.
I've been changing (improving) my driving habits all along, so I realize this isn't exactly a controlled test. Also, the weather has changed here in Indiana in the last month from Spring to Summer. So I guess what I'm saying is that I realize this isn't the cleanest data set but I thought others would find it interesting.
I've separated my data into morning & evening runs to account for the inherent differences (too long to go into all the details right now).
Most of the trends make sense to me. FYI, I'm definig "Relative Wind Speed" as the windspeed realtive to the direction I'm heading. For example, if the wind speed is 10 mph out of the south and I'm headed south, the relative wind speed is -10mph.
I supposed the best thing the stats show is the the highest dependency (R2 value) is mpg vs day which means the strongest factor influencing my mpg is probably the nut behind the wheel becoming more well tuned!
