I've been running the Spartan
250 tune for 18,000 miles.
All of the following mileage numbers are hand calculated.
Based on my particular in-town driving habits (which are very consistent day-to-day), my mileage was always 11 to 11.5 mpg, starting from the time I did the tune and delete (600 miles) to 14,000 miles.
At 14,000 miles my mileage began to increase for a few tanks of fuel, then leveled off at 12.5 mpg. I was very happy, especially because it was during the winter months and the fuel was probably winter-blend!
At 16,500 miles my mileage began dropping back to the 11 mpg range. I loaded the 210 tow-tune for a tank, just to see what it would do and only got 9 mpg. Loaded the 250 again and am still seeing only 11 to 11.5 mpg.
Where is my extra 1 to 1.5 mpg!!!!!!!!!!!
Oil and filter changed every 3,000 miles. The last fuel filter(s) change was at 15,000 miles, tire pressure is set at 65 psi (check it every fill-up) and my "Green" filter looks as good as the day I dropped it in.
Any thoughts or ideas?