How can I get the best fuel mileage gains from my Smarty?
First things first, your overhead fuel mileage readout is wrong! Every truck we’ve installed a Smarty and calculated the mileage by hand, has been off anywhere from 1-3 mpg. The only thing accurate about the overhead readout is that its inaccurate. My personal 2007 5.9L reads 17.6mpg combined. Hand calculated I regularly get 15.4mpg. The first thing you need to do is establish a reliable baseline of your current fuel mileage. Run a few tanks of fuel through your truck and hand calculate the results each time. Ideally fuel up at the same location and drive somewhat consistently.
With the Smarty, Mads Electronics has determined a reduction in fuel consumption up to 15% is obtainable. There’s a couple ways you can maximize these fuel mileage gains. Make sure you select a power level with timing. On the Smarty JR all power levels add timing. The general concept is this. The higher in the power levels you go (provided you can keep your foot out of the Accelerator), the better fuel economy your going to get. The reason being, you are working the engine less and achieving the same thing. If applicable take advantage of the Power on Demand function. Lets say your used to driving around at 1/4 throttle with your stock truck. Then you decide to add power with a Smarty. That same throttle position will end up using more fuel. By fine tuning the PoD to compensate for this change you will be able to get the highest possible fuel mileage.
Torque Management can adversely effect fuel economy if set higher than the default. The truck manages how much torque can be put down based on wheel speed, and limits the fueling accordingly. For fuel economy, this is a good thing! If you crank the Torque Management setting up, you will have more fueling available at lower speeds, which can hinder fuel economy. The bottom line is this. Your right foot will have the biggest effect on fuel economy. It doesn’t matter how much tuning you put into the truck if you always have the pedal down.