Last Updated June 12, 2023 | Andrew Boyle

SRW and DRW, which stand for single rear wheel and dual rear wheel respectively, refer to the number of rear wheels placed on a truck. That much is obvious. While SRW is the standard wheel layout of pretty much any vehicle, many heavy-duty trucks, including the Ford F-350, the Chevy Silverado 3500, the GMC Sierra 3500 HD, and the Ram 3500 all have DRW, or duallys, as an option. If you plan on towing heavy loads, like a boat, an RV, or a large trailer, then you may want to opt for a DRW truck. If your truck is more of your daily driver and only an occasional tower, then an SRW truck would be a better option. Regardless, there are plenty of other reasons you might want to opt for one over the other.

What Is a Dually?

A DRW truck, or a dually, is any with two pairs of rear wheels. The extra set of rear wheels spreads out the burden of the truck’s weight, allows for more contact with the road, and helps balance the vehicle. Duallys are quite noticeable on highways given that the extra wheel does give them a much larger appearance. Since DRWs are only options on heavy-duty trucks, you are unlikely to spot a dually Ford Fiesta anytime soon. In order for a truck to be DRW, it needs a tougher and larger rear axle, as well as elongated fenders that can effectively cover both wheels. This means you can't simply pop a second set of tires on any old truck. It needs to be a large truck that is built for this purpose.

Red F150 Towing Camper

What Does SRW Mean?

SRW trucks are trucks with only one pair of rear wheels. In other words, it's just a regular truck. For most truck owners, who mainly haul loads in their bed or occasionally tow moderately sized loads, an SRW is completely satisfactory. Now that trucks are many people’s daily vehicles, driving an SRW could make daily driving tasks easier. Not only will you save a bit of gas by opting for a single rear-wheel truck, but you will also save money on tires. Having a whole other set of tires does mean that you do have to buy and maintain them. Even though there are some benefits to duallys, there is a definite cost. At the end of the day, you'll just have to figure out how to tow that line for yourself.

Differences Between SRW and DRW

What's the difference between SRW and DRW then? It mostly comes down to desired towing capacity and the driving habits of the truck owner. As it would appear, duallys offer a higher towing capacity than their single rear-wheel counterparts do. The widened base of the truck not only means that it can tow more, but that it also has the ability to better maintain stability.

Consequently, the wider the base of the truck, the more space it will take up in the road; trucks sporting dually wheels on the highway do sometimes seem to take up an entire lane. Again, for heavy towing, this is necessary, but for daily driving, it may be a hassle, especially when it comes time to park. Even though truck drivers do pride themselves on their ability to maneuver their rig throughout even the most crowded spaces with ease, why put extra strain on your daily drive unless you absolutely need the added towing capacity?

Beyond that, with DRWs, there is a whole extra set of tires and wheels that need to be maintained. That in itself is an added cost down the line for DRW vehicles. Additionally, the tire wear is greater on DRW vehicles than on SRW, so not only is there a whole other set of tires to look after, but the back four tires endure more wear and tear. Dual rear wheels also have to be routinely rotated in order to distribute the wear and tear they endure. Essentially, more tires, more problems.

Dual Rear Wheel Towing Capacity

Gray F450 Towing Large Trailer

How much do duallys increase towing capacity then? Trucks with DRW can tow significantly more than their SRW counterparts. For example, the Ford F-350 with a diesel engine and single rear wheels can tow a max of 18,000 lbs while with duallys it can tow 21,000 lbs. When combined with gooseneck towing, DRWs can tow even higher amounts than that.

Ultimately, the benefits of DRWs are significant enough to pay attention to. If you intend on towing a lot of heavy items, then duallys are a good option. If you plan more on using your truck as a daily driver, however, and only using it to intermittently tow lighter loads, the SRW would be a good option as well. However, if you do intend on using your truck as a daily, then you might also want to opt for a lighter quarter-ton truck rather than the majority of dually equipped trucks which are one-ton trucks and up. Regardless of your choice, CJ Pony Parts will have the parts you need.

This article was researched, written, edited, and reviewed following the steps outlined in our editorial process. Learn more about CJ's editorial standards and guidelines.