Hobbies Cars & Motorcycles Modifying Your Truck to Improve Gas Mileage Fuel Costs vs. the Expense to Modify Your Truck Share PINTEREST Email Print Aliaksandr Bukatsich/iStock/Getty Images Cars & Motorcycles Trucks Cars Motorcycles Used Cars SUVs ATVs & Off Road Public Transportation By Dale Wickell Dale Wickell is an automotive expert who has worked in the industry for more than four decades. He currently works for LeMay - America's Car Museum. our editorial process Dale Wickell Updated April 18, 2018 With the price fuel trending upwards, truck owners are looking for as many ways as possible to get better fuel mileage. You've probably already tried the simple things you can do to suck more miles out of a full tank, like avoiding unnecessary idling, eliminating quick accelerations, and making sure your tire pressure is correct. Those steps are good, but they won't up your mileage by leaps and bounds. So what can you try next? That topic is coming up more often lately in conversations with friends and colleagues. One of my friends has a diesel pickup that he's been thinking about outfitting with a cold air intake, a free flow exhaust system, and a computer programmer to modify the engine setup — all things that can help improve fuel mileage. The modifications will cost about $1,000. He asked me if I thought the changes were a good idea since he knows I get gas-saving queries from people every day. My reply: it depends on. If your goal is to save fuel for environmental reasons, and you don't mind the cost, you probably don't have to think too hard about purchasing the add-ons. But if saving fuel to save money is your primary goal, buying a thousand dollars worth of parts might not be the answer. Do the Math of Fuel Usage Let's find out how much fuel you use in a year by taking a look at your current fuel mileage and the average number of miles you drive annually. Considering the benefits versus cost will help you determine if modifications fit your needs. Annual miles driven divided by your truck's average miles per gallon = the total gallons used per year. Do that math.Multiply the answer in Step 1 by the average price of fuel per gallon to determine about how much you spend on fuel each year.Next, estimate how much the modifications will increase your fuel mileage. Be conservative, because the advertisements for each product are usually off.Using the new mpg figure, repeat the calculations in Steps 1 and 2 to estimate how much you'll spend on gas on the modifications.Subtract the new dollar amount from the original figure to find your annual savings after adding modifications to the truck.Now divide the price spent for modifications by the annual cash savings to determine how many years it will take to cover the cost of the modifications. Here's a Real Life Example 20,000 miles driven in a year divided by 15 mpg = 1,333 gallons used per year.1,333 X $3.00 (for each gallon of regular gas) = $3,999 spent on fuel for the year.The three modifications we've talked about could possibly increase the truck's fuel economy by 3 mpg. Redo the calculations:20,000 miles per year divided by 18 mpg = 1,111 gallons of fuel per year.Multiply that figure, 1,111, by $3.00 per gallon for an estimate of $3,333 per year for fuel.Now take $3999 (before modifications) and subtract $3,333 (after modifications) to find your yearly fuel savings, $666.Divide the cost of modifications, $1,000, by the savings, $666, to determine how long it will take to recover the expense of updates. In this case, the answer is 1.5 years or 30,000 miles. Will you keep the truck that much longer? If you drive fewer miles each year, and if the per gallon savings are less, it will take more time to recover your expenses. On the other hand, if gas prices keep climbing upwards, you may see a return in less time. Modifying Your Truck to Increase Its Power The cost of modifications might be a good investment if you are making changes to gain power (which all three updates will provide), because you want to help reduce fuel dependency, or because you want your truck to have a certain look or sound. Take all of those elements into consideration and keep in mind that there are no right or wrong decisions — it's your money and your truck. Do what works for you.