I have a 2003 Tacoma Doulecab Prerunner V6 TRD (larger tires) and have been following the mileage thread. I just got back from a trip to Florida and have some interesting data.
I set my trip odo at the Georgia border today and when I saw the mile marker for 99 miles, my trip ODO read 93.6 miles. I logged again in South Carolina
79 miles by markers and 74.9 miles by ODO. Then one last time on I77 85 miles by markers and 81 miles by ODO. If you do the math:99/93.6 = 1.057
79/74.9 = 1.054 85/81 = 1.049The average ratio of Actual/ODO = 1.054
I tried to check the speedo, but without instantaneous measurements it is hard to do. Over about a 10 minute average, when the needle was on 65, I calculated a speed of 66.7. However, I'm not very confident in that number.
I also logged two fill ups for gas mileage:
344.8 miles 15.147 gallons = 22.764 mpg 282.8 miles 12.222 gallons = 23.128 mpgHowever, if you adjust the mpg for the 5.4% difference in actual and ODO miles, then
363.398 miles 15.147 gallons = 24.387 mpg 298.054 miles 12.222 gallons = 23.991 mpgMy old 97 V6 2WD 4Runner got consistently 24mpg on the highway so this is not that far off. As a side note, I did also keep the speed down at 65 mph and below. I have found that driving above 65 tends to burn the gas faster. Also, keeping the truck out of passing gear helps too. If the cruise is set and you come to a grade, my Taco jumps into passing gear and that tends to drink gas.
I hope this helps the discussion on Taco mileage. I'm going to run come calculations to see if the 5.4% difference makes sense for the larger tire size.
Enjoy,
Brian