Fuel Doctor Review – Introduction and Test Procedure

>> 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.

February 1, 2011 – From a very early age I can remember thinking and wondering about fuel economy. While yet still quite young I came to the conclusion that absent drastic change in fuel economy it would be rather likely that we would run out of petroleum in our lifetime. I spend a lot of time thinking about how to improve fuel economy and have tested many of my personal theories and inventions. I have also tested devices or products available for sale to the general public. Some of these devices have worked while others have only served to lighten my wallet. I take nothing for granted and have found in a few instances that the general consensus is off base or completely wrong. I am a hands-on kind of guy and most of what I write about is based on my personal observations and testing.

Toby the Fuel Doctor tester next to his 2004 Tundra

When Jason contacted me asking if I would be interested in testing the Fuel Doctor for TundraHeadquarters.com and writing a review of the device, I was eager to get started. I must admit to a fair degree of skepticism after reading both how this device is purported operate and in the gains claimed. I know from personal experience that a 10% gain in fuel economy is an impressive improvement. Even so, I will test the Fuel Doctor in as scientific a manner as possible using a Scanguage II and the old reliable pen, paper, and calculator.

During the course of my testing over the years I have come to a few conclusions as they relate to fuel economy improvements. I have noticed that, after installing certain fuel saving devices, I recorded an initial gain in miles per gallon over the first few tanks of fuel. Over time those gains slowly disappeared until the average MPG’s returned to where they where pre-installation. One of my overriding criteria in testing as to whether a device or modification works is the test of time. Any gains realized must be sustained.

Testing Grounds:

Initial testing will be conducted in the Indianapolis near on I-74 between Post Road and the London Road Exit 103 which is approximately 10 miles. Refueling will take place at the Shell gas station on I-74 and Post Road using Pump #12. Long term testing will be conducted during typical driving conditions and the numbers will be compared against the average MPG’s for the truck to look for improvement.

Testing Procedure:

At least two tanks of fuel from Shell gas station on I-74 and London Road using Pump #12 will be run in order to have consistent fuel type and quality present in the tank before testing commences. It is important to understand that over the years I have found the fuel from this particular station to be of consistent quality through very careful MPG tracking. I specify pump #12 because I am usually able to access this pump without excessive waiting times. All testing will be done using fuel from said gas pump. The use of the same pump will reduce pumping variances encountered when using different pumps. The most reliable testing conditions are on the highway with cruise control as this eliminates individual driver’s personal driving characteristics. Additionally no drafting of other vehicles will be considered acceptable testing procedure.

Several tests will be conducted during the initial stages:

• Test run #1 will be a run from the Post Road Exit 95 to the London Road Exit and back again without the Fuel Doctor 47 installed. Cruise control will be set at 70 Miles per Hour both directions. MPG data will be collected by the Scanguage and recorded on paper.
• Test run #2 will be a run from the Post Road exit to the London Road Exit and back again; this time with the Fuel Doctor 47 installed. Cruise control will be set at 70 Miles per Hour both directions. MPG data will be collected by the Scanguage and recorded on paper.

The mileage numbers from the two tests will be compared in order to detect any change (improvement) in the miles per gallon.

Long term testing will be conducted over a distance of at least 1,000 miles (and up to 3,000 miles) through the course of normal daily driving. This will include a mix of city driving as well as highway miles. There may be some extended highway driving. As with the initial testing all data will be recorded using the Scanguage II unit and all numbers will be checked against fuel receipts and odometer readings.

Test Vehicle:

All testing will take place using my 2004 Toyota Tundra Double Cab. This truck has a 4.7 liter V8 with a four speed automatic transmission and four wheel drive. Currently I have over 194,000 miles on the odometer and over the summer I averaged 17.5 MPG. With the arrival of winter-grade fuel and freezing temperatures I expect to see a drop of several miles per gallon.

Modifications on my truck to date include:

• Replaced stock 4:10 gears with 3:91 gears in front and rear differential
• True Flow air intake with a drop-in True Flow oiled filter
• Stock resonator replaced with a glass pack
• Stock muffler replaced with an Aeroturbine
• Splits from the rear of the Aeroturbine over the axle and out to each corner of the rear bumper
• Fitch Fuel Catalyst
• Ram air intake scoop with direct connect to the air box

Personal Expectations:

The simple fact that this device plugs into a cigarette lighter and is supposed to improve fuel economy raises serious doubts as to the veracity of this claim. My personal expectation is that the Fuel Doctor will have absolutely no affect on fuel economy. I cannot imagine that sticking something in the cigarette lighter can possibly improve fuel economy.

If you have questions please do not hesitate to shoot me an email at highwaylizard[at]gmail[dot]com and I will do my best to get an answer out to you in a timely fashion. Be advised that I am a single father working and raising a son in conjunction with my research so if I do not respond to you right away send me another email a week or two later. In the meantime feel free to visit my Blog on Tundra Fuel Economy.