Diesel VS Gas: What Is Best For Towing An RV?

According to data collected by RV RoadSigns for the RV Industry Association, an estimated 332,400 to 366,100 recreational vehicle units will ship in 2026, a marked increase from the previous year. That means more travelers will be taking to the roads and seeing the sights of the U.S. while towing anything from small campers to colossal fifth wheels, or even this absurd $110K destination trailer with two bedrooms, a deck, and full-sized appliances. However, many new to the RV scene may wonder what kind of vehicle they need to pull one of these trailers. Specifically, should they opt for a diesel over a gas model?

Both options have their own pros and cons, but with regard to towing performance, diesel typically outperforms gas in available low-range torque. However, that's only part of the picture, and there are other aspects to consider such as purchase price and fuel economy. So, if you're still on the fence about which type of truck to get, let's dive into a direct comparison of the data to help you determine which one is right for you.

When looking at pickups, it's not only horsepower figures that matter, but also how much torque they can produce. Torque is the amount of twisting force an engine can exert, which is crucial when towing. In general, diesels tend to produce more torque for a variety of reasons. For instance, the pistons in a diesel engine move higher in the cylinders than in a gas engine, allowing for additional compression. A diesel runs this way because, without spark plugs, each piston must generate enough heat to cause combustion, which is achieved through that extra compression at the top of the cylinder.

In addition, diesel fuel is more potent than gasoline. In fact, 1 gallon of diesel will offer around 10-15% more energy than an equivalent amount of gas. With more energy, a diesel can generate more power (including torque), which allows you to pull a significant amount of weight, often times more than gasoline engines can manage.

The size of your RV may dictate which truck you need. Fifth-wheels can weigh more than 15,000 pounds, and it isn't just towing capacity that's important. Payload is also a consideration, as even some of the lightest fifth-wheel's pack a 1,560-pound hitch weight. Because gasoline-powered trucks don't have as many heavy components as a diesel, they often feature a higher payload capacity, so you'll need to consider your options carefully.

While a diesel may offer you more pulling power, it'll also cost you more upfront. Data by Cox Automotive, as reported by Axios, shows the average price for a new pickup in early 2025 was nearly $60,000 — hardly an inexpensive purchase, and if you want a diesel, it gets worse. You could be looking at anywhere from an additional $8,000 to $11,000 above the cost of a gas truck.

The reason for the uptick in sticker price has to do with the fact that diesel engines are made with more robust components that offer greater intervals between scheduled maintenance. Considering that these engines may see rigorous workloads, the parts generally offer greater reliability and longevity, especially when running heavy workloads for extended periods. While a gas truck can handle challenging tasks, too, it's better for their lifespan if these tasks are infrequent. However, due to factors like more numerous and expensive components, and the fact that diesel emission systems can clog, maintenance on a diesel can be much more expensive than on a gas truck.

If you've ever had the misfortune to need a replacement diesel particulate filter (DPF), you're aware they can run you as much as $10,000. That's is why if you do opt for diesel, you'll want to know how to prevent your DPF from getting clogged, as this issue could lead to lackluster performance and, eventually, component failure. A gas truck has the benefit of not needing as many extra emissions components.

According to the U.S. Department of Energy, diesel-powered automobiles can go 20% to 35% further on a gallon of fuel than a gasoline-powered vehicle. Car and Driver put this to the test when they measured fuel efficiency across nearly two dozen heavy-duty trucks and discovered that the diesel's got around 18 mpg, while the gas pickups only managed 15 mpg. In fact, many of the new trucks with the best MPG feature either hybrids or diesels under the hood. In terms of towing an RV, this means a diesel won't have you stopping at the pumps nearly as often.

However, the average price for diesel fuel is higher than gas and, outside of a few instances, has been since around 2004. This is due to higher demand, increases in production cost, and a federal tax of 24.40 cents per gallon. According to AAA, the national average cost for regular gas is $3.071 per gallon, while diesel is sitting at $3.739. For a cross-country RV trip, this small difference can add up, but perhaps not quite as much as you may think. For a 1,000-mile trip, a gas truck averaging around 15 mpg will use $200 in regular fuel. In comparison, a diesel getting 18 mpg will cost about $208 (based on the national average fuel prices).