Fuel Doctor Review – Does it Work?
This week we’ll be reviewing the Fuel Doctor, a fuel saving device that I encountered at the 2010 SEMA show last November.
Conducting this review will be Toby K, who runs his own Tundra Fuel Economy blog where he writes about fuel saving devices. Over each of the next five days, you’ll read a post from Toby describing his testing process. At the end, you’ll learn the following:
The Fuel Doctor really works – or at least it did for this specific test.
The Fuel Doctor touts something called “electronic signal conditioning,” and according to their Chief Technical Officer Doug Hungerford, the Fuel Doctor can improve fuel economy in the right circumstances. According to our admittedly small test, it does. Here’s the whole story:
How The Fuel Doctor Test Started
When I met Doug Hungerford of Fuel Doctor USA at SEMA, he told me three important things about the Fuel Doctor device:
- It doesn’t work on vehicles less than 2-3 years old. Period. If your car or truck is less than two years old, don’t buy a Fuel Doctor. Less than three years old? Probably not.
- It “conditions” electric signals to eliminate spikes in voltage. The concept is, voltage spikes interfere with various sensors and introduce a certain amount of error into the vehicle’s engine management system. Over time, this degrades performance.
- It doesn’t always improve gas mileage. Doug was up-front about the fact that sometimes, Fuel Doctor just doesn’t work. It’s not effective 100% of the time.
Naturally, when I heard these three conditions last November, I was skeptical. Hugely skeptical. I’m not an automotive engineer, but I have an engineering degree, I took a couple of electrical engineering classes, and six months ago I would have told you that this device couldn’t possibly work because vehicles already have conditioning circuits. Every car, truck, or SUV made in the last 20+ years has some sort of conditioning circuit similar to the circuit contained in the Fuel Doctor.
However, Doug was convincing. He showed me an oscilloscope test to demonstrate how much the Fuel Doctor device reduced voltage spikes, and he offered us a free testing unit. I was blunt – I told him I didn’t think it would work and that our test might not go well for them. He reiterated that it probably wouldn’t help a newer car, but that drivers of older vehicles almost always noticed an improvement.
Obviously, I took Doug up on his offer for a free test unit. I contacted Toby, and after a little back and forth, we got the test started. According to careful testing – which has lasted three months and which includes more than 5,000 miles of travel – the device improved the mileage on his 2004 Toyota Tundra by about 2 mpg. Considering the Fuel Doctor costs $50, that’s a pretty good deal. A one mile per gallon improvement on the average pickup means that you’ll go an extra 20-30 miles on a full tank. Over the course of one year – assuming 15,000 miles traveled, an average of 14.5 mpg prior to install, and a gas price of $4 per gallon – that’s $499 dollars worth of annual gas savings.
Now, it must be noted that this was just one test. You could buy this device and find out it didn’t do a thing. However, considering the upside and possible fuel savings, you may want to check it out.
Here’s all the articles Toby has written about his test process:
- Introduction and Fuel Doctor Test Procedure
- Initial Impressions of Fuel Doctor Device
- Initial Test Results – 1.5 mpg improvement
- Long-term Test Results – The Fuel Doctor Worked
Fuel Doctor Test Specs
Test Vehicle: 2004 Toyota Tundra 4.7L V8 with approximately 194,000 miles
Test Location: Indianapolis Area, IN
Distance Traveled During Test: 5,703.6 miles
Average Fuel Economy Prior To Install: 14.5 mpg (as stated by Toby, his average for months prior)
Average Fuel Economy After Installing Fuel Doctor: 16.49 mpg
Measured Gain: 2 mpg
Standard Deviation: 0.75 mpg
Variance: 0.56 mpg
Special thanks to Toby for conducting this test – be sure to visit his Tundra Fuel Economy Blog!
Filed Under: Toyota Tundra Accessories