Diesel is expensive, and it isn't getting any cheaper. European nations have complained for years about gas and diesel prices that can be as high as $5 per gallon, and it looks like it's finally our turn. With this in mind, we took a look at the Fitch Fuel Catalyst, a device that's reported to increase mileage by 5 to 12 percent.
We have to come right out and admit that we're not exactly sure how it works. There's a canister that houses a bunch of metallic rods that look like giant match sticks. We're comfortable with things like propane, which acts as an added fuel and increases fuel economy, but we were stumped when we took a look at the Fitch.
We know it has something to do with an additional pretreatment process of the fuel, but we thought it would be more fun for us to test one than to try and explain how it functions. What was interesting is we actually talked to some other magazine guys about the product, and they swore it worked. We were eager to check it out and see if our results were the same as theirs.
The Fitch Fuel Catalyst installation was fairly straightforward because the Fitch is a bolt-on design that mounts on the intake. However, we would be changing turbos and intercoolers, and we were worried about nitrous backfires, so we mounted it along the frame-out of the way of potential danger.
After talking with Jason Taylor from Orange County Diesel, we decided the best place to mount our Fitch Fuel Catalyst was along the frame where the factory quick-disconnect fuel line ran, so our first step was to disconnect the fuel line (arrow) using the tool provided. After the lines were disconnected, we clamped on the rubber fuel lines included in the Fitch kit. | 
Holes were then drilled into the frame and tapped to create a secure mounting position for the Fitch unit. | 
The Fitch was mounted along the frame with straps provided in the kit, and the fuel lines were connected. |
This is what the Fitch looked like after the install. It was fast, easy, and we had it mounted out of the way where we didn't have to worry about it. | 
Getting the truck started again was the most difficult part of the whole task. The Fitch had to be completely filled with fuel before the truck would run, so we loosened (slightly) a couple of the injector lines and cranked the engine to draw fuel up from the tank (the 12-valves have a mechanical lift pump). After about 5 minutes of on-and-off cranking every 30 seconds or so, the truck finally fired up. | 
After about 500 miles of driving, we had some good numbers and decided to see what we would get with the Fitch out of the equation, so we had Jason Carrier from Xtreme Diesel and Exhaust disconnect the lines from the Fitch, loop them, and connect the factory lines back together. With a lift, this step took just a couple of minutes. We were then able to get back-to-back-to-back fuel-mileage numbers with and without the Fitch installed. |