Tire inflation pressure is indeed important, but so is the type of tire that you use on your motorhome. A tire that is wider than necessary typically produces a better ride, but it can also increase rolling resistance. A narrower, heavy-duty tire will ride rougher than its wide, cushy counterpart, so you’ll have to ask yourself if you’re willing to sacrifice a little bit of comfort for improved fuel economy. I should note here that a larger diameter tire won’t hurt fuel economy and may even help it, because a larger diameter tire turns fewer revolutions to cover the same distance, and engine rpm is lowered as a result.

Alignment is also extremely important. Incorrect alignment can cause a lot of resistance, requiring more throttle input to maintain a given speed. “Toe in” is the most critical setting of them all. Simply put, “toe in” means the front of the tires are “pigeon toed”. Obviously, too much toe will also cause your tires to wear more quickly.

It’s a good idea to have the alignment checked on your recreational vehicle even when the motorhome is new, because the factory runs them through the alignment procedure pretty fast. And, when the motorhome is loaded for travel, especially an independent front suspension (IFS) coach, the alignment changes as the load changes. The only exception is self-leveling, air suspension coaches, where correct ride height is constantly maintained.

Straight axle recreational vehicles don’t change as much, but it’s still a good idea to check the alignment when loaded. One of the things we always recommend to our customers is that they ask the alignment shop, “When was the last time your equipment was calibrated?” At our shop, we measure our alignment jobs in hundredths of an inch. This is important, because if the toe in is just 1/8-inch off spec, that is equal to 28 feet of side scrub per mile—a lot of resistance and tire wear.

Some toe in is necessary when the recreational vehicle is in the static (parked) position, because as the vehicle travels down the road the front wheels will open up, and actually be pointing straight (zero toe in). This happens because most motorhomes have what is known as a “positive scrub radius” on the front axle.

On some older RVs, we’ve found that the front alignment needs to be toed in a full ¼ inch at the static setting. The typical alignment shop would think that’s nuts, but we experimented with it, and that’s how much they require to stay at zero toe-in in the dynamic (moving) position. Static settings are important, but I’m more concerned with what the vehicle is doing as it drives down the road.

A lot of RVers don’t know that the rear axle, or axles, can also be out of alignment—and if that’s the case, this problem can increase resistance and tire wear, reduce fuel economy and cause handling issues. The axle may be askew or not installed properly from the factory—the end result being rear wheel steering.

Have you ever been following a motorhome that looks like it’s going down the road a little sideways? We call that “Rut tracking.” The driver keeps the wheel turned to compensate for it, and creates scrub. At the same time, aerodynamic efficiency is reduced, because more surface area is exposed to wind resistance.

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