Rick - I agree 100% with your thoughts on not driving erratically or aggressive and not doing fast starts/stops. Your comments on driving slower got me wondering about the savings from that so here is what I came up with:
17,500 miles per year. If your yearly average speed (City/highway) was 40mph, your total drive time is 437.5 hours.
If you drop your average speed down to 30mph, your drive time goes up to 583 hours.
This increase of time is 145.8 hours. At 30mph, that equals 4,374 miles. So even though you don't actually drive more than 17,500 miles/year, the extra drive time has the effect of adding 4,374 miles. This would give you an effective total travel of 21,874. If your mileage rate increases 15% because of the lower speed, you would average 18.4 mpg. At this mileage rate, you would use 1,189 gallons at $2.95/gallon equals $3,507.55.
Did I figure that right?
Using your previous numbers:
Average miles traveled per year…. 17,500
Divided by average MPG…………16
Equals……………………………..1093 gallons of fuel used
Times………………………………$2.95 today’s fuel price
Equals……………………………..$3,224 annual fuel expense
Slowing your average speed by 10mph can cost you almost $300 more.
So unless the mileage economy in our cars changes more than 15% from the change in speed, just slowing down doesn't look like it will help.
This whole load of crap I just figure out only looks at driving speed. I agree with you that most of the inefficiency we have while driving is from the quick start/stops and the jamming on the accellerator to pass or get up to speed really quick. If we can stop those habits we will probably save a lot.