Fuel Doctor – Long Term Test Results
Jason Lancaster | May 26, 2011 | Comments 3
>> Be sure to check our official Fuel Doctor review post to see if it really works!
Guest Post By Toby of Tundra Fuel Economy blog.
May 2nd, 2011 – At this point the Fuel Doctor has been installed and tested for only a little more than 5,300 miles. During that time I have tracked my fuel economy using both my Scanguage and the tried and proven method of miles driven divided by gallons pumped to full. Each time I refuel I try and use the same pump in order to minimize pumping variances and I always fill the tank full.
Here is the raw data from the testing so far:
| Date | Miles | Gallons | Cost | Brand | MPG | Rolling AVG MPG |
| 02/11/11 | 317.1 | 21.32 | $3.00 | Marathon | 14.87 | |
| 02/16/11 | 322.2 | 20.58 | $2.96 | Marathon | 15.66 | 15.26 |
| 02/18/11** | 236.4 | 14.24 | $3.20 | Marathon | 16.6 | 15.6 |
| 02/18/11 | 328.4 | 18.87 | $3.20 | Marathon | 17.41 | 16.05 |
| 02/25/11 | 326.8 | 19.64 | $3.36 | Marathon | 16.64 | 16.17 |
| 02/27/11 | 95.5 | 5.89 | $3.46 | Marathon | 16.21 | 16.53 |
| 02/28/11 | 258 | 17.12 | $3.40 | Shell | 15.07 | 16.44 |
| 03/03/11 | 257.2 | 15.86 | $3.56 | Marathon | 16.22 | 16.36 |
| 03/06/11 | 307.2 | 20 | $3.56 | Marathon | 15.36 | 15.85 |
| 03/12/11 | 355.6 | 22.09 | $3.66 | Marathon | 16.1 | 15.73 |
| 03/15/11 | 287.5 | 17.42 | $3.60 | Marathon | 16.51 | 15.85 |
| 03/29/11 | 345.4 | 21.19 | $3.60 | Marathon | 16.3 | 16.08 |
| 04/02/11 | 300.5 | 17.72 | $3.68 | Marathon | 16.95 | 16.22 |
| 04/05/11 | 321.3 | 20.94 | $3.86 | Marathon | 15.34 | 16.21 |
| 04/08/11 | 283.7 | 17.87 | $3.86 | Marathon | 15.87 | 16.17 |
| 04/13/11 | 336.2 | 20.16 | $4.00 | Marathon | 16.68 | 16.21 |
| 04/16/11 | 281.5 | 17.4 | $3.88 | Shell | 16.18 | 16.19 |
| 04/21/11 | 386.4 | 22 | $4.00 | Marathon | 17.56 | 16.36 |
| 04/24/11 | 321.4 | 18.26 | $3.73 | Marathon | 17.6 | 16.82 |
| 04/26/11 | 331.9 | 18.98 | $4.10 | Marathon | 17.49 | 17.12 |
| 05/02/11 | 342.7 | 20.24 | $4.29 | Marathon | 16.94 | 17.18 |
| TOTAL: | 5703.6 miles | 345.88 gallons | FUEL DOCTOR AVERAGE: | 16.49 mpg |
** Entry #3 (2-18-2011) I installed the Fuel Doctor prior to running my fiancé, her sister, and two nieces up to Chicago O’Hare International Airport for their trip to Italy. The run up and back I had pretty good conditions despite some incredible vibrations. In fact the vibrating was so bad I had back problems for a few days afterward.
Entry #4 (2-18-2011) was a fill-up at a Marathon on the way to Chicago, Illinois.
Entry#7 (2-28-2011) was the run up to Chicago and back to pick up my fiancé, her sister, and two nieces from Chicago O’Hare International Airport upon their return from Italy. I fueled up at a Shell gas station.
Entry #17 (4-16-2011) was a fill-up at a Shell gas station in Brownsburg, Indiana.
Entry #19 (4-24-2011) was a fill-up at a Marathon in Evansville, Indiana.
Summer blend fuel has, per EPA rules, has already begun arriving in my area. Seeing as I am only halfway through my testing of the Fuel Doctor this is not too much of a problem. In another month the fuel at my local gas station should be pretty consistent in terms of summer/winter blend fuel and the mileage numbers will stabilize for the balance of the testing period. I will pull the Fuel Doctor at the end of May and run a month without it to re-establish the baseline numbers and then run another 4,000 miles of testing.
I just replaced the front driver’s side wheel bearing at 206,425 miles which I hope will have a measurable impact on fuel economy. In light of this and the changeover from winter blend fuel to summer blend fuel I will wait until the first of June to resume testing although I will continue to record data.
Filed Under: Toyota Tundra Accessories
Looks good so far Toby. I would also test it with mid grqade and premium just to see if it gets better with the higher octane.
Mickey – Interesting idea. Supposedly, fuel grade makes no difference, but quite a few people have told me that it’s helped them to use premium.
It was just a thought. If I decide to get one I would try it just to see if it mek it worthy to get premium.