Fuelly
Gas prices are going up, and I’ve been looking for ways to improve fuel efficiency of my vehicles. Readers of my blog know that my everyday car is a Prius, so I’m in pretty good shape there. But when the weather’s bad, I also drive a 2004 Ford F-350 with a snowplow. It’s a good, solid tough truck which can pull my heavy trailer. But a tank of gas for it is starting to run about $75, so I’m looking for ways to improve its mileage.
In order to make some improvements, I tried two things over the last couple of months. First, I installed a Kiwi mileage meter. This is a simple device that fits well with my ‘You Get What You Measure’ philosophy. It plugs into the truck’s OBDII port (an onboard diagnostics port that all newer vehicles are equipped with), and outputs mileage information in real time. Of course, the Prius has a famously prominent mileage meter, which does indeed ‘train’ you over time to achieve higher numbers. But I’ve never had a mileage meter in the truck before. The Kiwi works - you can watch it there on the dash telling you you’re getting 8MPG – not good. One of the most interesting things has been that I can really see the mileage going down in the winter, which is typical as the weather gets colder. I’ve definitely seen a couple mpg drop.
Next, given that I had some basic mileage info (however bad it might be), I tried an aerodynamic improvement. I have a construction cap on the truck, which I love for the toolboxes, the room, and the ladder rack. However, it has a completely squared off back end, so it’s about as aerodynamic as a brick, and I did have the feeling that the mileage dropped off after I installed it. Inspired by the spoilers that many school buses have now, I looked for a similar option, eventually arriving at ‘Airtabs’. These are basically small stick-on spoilers that you apply all over the trailing edge of the vehicle so that the squared-off rear end won’t create as much aerodynamic drag. And they cost less than a tank of gas, so what the heck.
So do they work? At this point, my data is not at all scientific, but I think I do notice some minor improvement in mileage in highway driving. However, I don’t drive the truck on the highway much, and there have been some confounding factors, including the onset of cold weather mentioned above. Plus, this has been a big year for snowplowing, a decidedly low mileage activity.
In order to get a little more scientific in my approach, I’ve begun entering my fuel purchases on Fuelly.com . This is a site that allows you to track your mileage performance and compare it to other drivers. At first, it seemed impractical to enter this information at every fill-up, but now I’ve developed a system. I just scribble the mileage on the gas pump receipt and throw it on my dash. When I get around to it, I enter the info on the fuelly.com website. I recommend this site, by the way – it’s simple and straightforward. I’ve only got three or four fuel-ups loaded in there so far, but I think it’s going to be a real eye-opener. Right now my truck is averaging 10.7 mpg (better than expected, given the plowing), and my Prius 43.4 (about right for winter; lower than what I see in the summer).
Another thing I have going in my favor is that at GAF, we have a very comprehensive transportation fuels management effort. I was able to go to a couple of our experts, including Director of Transportation John Scarfi. John shared with me some of the techniques that have gotten results. Firstly, we have found great improvements in the last few years because of Advanced Protection technology, allowing us to optimize the weight and performance of our shingles, which in turn has allowed us to optimize the loading of our truck fleet. Also, we spec out our tractors and trailers to ensure that we are among the leaders in the industry in utilizing light weight equipment.
I plan to continue updating the results on Fuelly, and you can actually see my profile, which is called ConstructionCap. And I’m always looking for new ideas - let me know if you’ve tried anything to improve the mileage on your truck!


Martin Grohman
Reader Comments (2)
Gas prices are certainly a concern for Americans who have to stretch every paycheck, but they are a logical product of our inability to wean ourselves off foreign oil. With a more focused effort we could develop and build new technology that would make us energy independent. Drilling only supplements the huge supplies of oil we must import from other countries. Gas prices are not the problem; the problem is that we are so reliant on putting gas in our foreign-built cars.
Fill up your tank early in the morning and on cooler days. The colder the gasoline is, the more compact it is, you will therefore end up getting more fuel mileage for your money.