[Jim Sims]

Made a quick trip to Roswell, NM yesterday for a family wedding reception. I decided to attempt to drive to optimize fuel economy but drive the speed limit (speedometer error corrected) and not impede traffic and not do things like shut off the engine, coast in neutral, etc. Drove a stock 2004 BMW 325i sedan with five-speed manual transmission. Tires inflated to maximum payload levels: 35 psi front and 41 psi rear. Average payload, passenger and cargo, was 270 lbs. Used the cruise control once up to speed limit, when traffic permitted only accelerated at the power level permitted by 30 mpg. I didn't immediately accelerate to the speed limit when leaving a reduced speed limit (town) if acceleration had to be done going up a grade; waited until saddle point of hill was crested. If there was traffic I immediately accelerated to speed limit (8-12 mpg). Used air conditioning for about 3/4 of the total driving time. Wind was blowing from the corners of the car most of the time out on the flats (Llano); I estimated I had an effective head/tail wind of 5 to 10 mph much of the trip. Outside air temperatures were 75 to 90 F much of the trip. There were significant grades leaving and returning to Los Alamos at 7000 ft. Typically had to stop at about six stop lights each pass through Santa Fe (45 and 35 mph speed limits). The majority of the trip was done at 70 mph or 65 mph with lesser distances at 55, 50, 45, 40, 35 and 25 mph. Google Maps estimated driving time one-way was about four hours and five minutes; I made the distance (225 corrected miles) in approximately three hours and 45 minutes (60 mph average speed). 12.505 US gallons of mid-range unleaded fuel ($3.959/US gallon) was consumed: car was refueled at the same station and with the same pump.

35.99 mpg was achieved.

Traffic was very light. Saw a Chaves County sheriff's deputy pull over a Cadillac Escalade with Texas plates that passed me doing an estimated 90 mph.