Combined mileage when riding a motorcycle during the summer

I kept track during 2007 of the number of days where I could've ridden a scooter or motorcycle to/from work. I excluded days when I was on vacation, working at home, needed to do errands, or where the weather report called for rain with chance of precipitation >= 50%. According to these rules, I could've ridden a motorcycle to work 59 times in 2007. With a 26 mile round trip, this translates to 26 * 59 = 1534 miles a year.

I also calculated an estimate of the total number of days I commute to work at Florham Park, 26 miles roundtrip. This estimate took into consideration vacation, days when I went to Middletown or elsewhere and working at home one day a week. According to my calculations, I commuted to Florham Park 177 times. This translates to 177 * 26 = 4602 miles.

Finally, I made a rough estimate of the total number of miles I drive in an average year. This one is hard because it depends so much on how many and what kind of long distance road trips I take. For 2008, for example, a number of college visit road trips make this number larger than average. Anyway, I set this number at 10,000 miles but will recalculate for 2008. What is hard to work into these calculations are the miles near home where I now ride my bike. This mileage is probably pretty small, but the savings are disproportionate because of the poor fuel economy experienced on short trips.

So, commuting accounts for less than 50% of my driving, and of commuting, I could expect to ride a motorcycle a little more than one third of the time. To get my overall fuel economy, for 8400 miles a year, I use my automobile mileage figure of 25 mpg (this may be a little low). For 1600 miles, I use the expected motorcycle mileage of 70 mpg:

8400 @ 25 mpg = 336 gallons
1600 @ 70 mpg = 22.86 gallons

Total gallons: 358.86
Average mpg: 27.87

So, I improve my overall fuel economy by only around 3 mpg, and it's still less than what Ellie gets simply driving a Honda Fit all the time (average above 32 mpg). This means I need to a) find other opportunities to ride a motorcycle or bike, and b) drive a more fuel efficient car whenever possible. I'll have a better estimate of automobile miles in 2008.