European truckers have been using the 6×2 axle configuration on class 8 trucks for decades now. The uptake in the United States has been attributed to a lack of information in the past. More and more information is cropping up, however. In 2014 Trucking Efficiency released a confidence report on the advantages and disadvantages of the 6×2 setup, and this August they released a confidence report on lightweighting trucks; there is some crossover between the two concepts as a 6×2 tractor-trailer is lighter, around 400 pounds so.
There are reasons to be hesitant when considering the switch from a 6×2 setup, concerns like tire wear and traction. Tires do wear out faster on 6×2, but the costs are more than made up for by resulting savings on fuel. Truck owners can also save costs by using less expensive tires, or retread ones, on the tag axle, since it will not be on the ground as much as the drive axle. Because the suspensions are adjustable, there will be less rolling resistance, as well. Traction should not be a problem; Meritor Wabco’s Electronically Controlled Air Suspension (ECAS) can transfer weight from the tag axle to the drive axle, giving traction as needed. ECAS also automatically adjusts the suspension to the current load on the truck. Volvo released Adaptive Loading in March, which uses Electronic Controlled Suspension, similar to Meritor’s ECAS.
Testing thus far still shows the 6×2 to be around 2% more fuel efficient than the 6×4 configuration. Volvo’s new truck suspension also boasts improved fuel economy under certain circumstances; switching the ECS to 6×4 configuration cuts rolling resistance and thus drag, saving fuel. Still, fuel efficiency diminishes with time, and when it comes time to upgrade to a newer truck, a lot of owners worry about being able to sell their 6x2s. This is reasonable, as the more efficient tractors face hassles depending on the state, and the style has not exactly caught on yet. It is likely, especially considering the Phase 2 regulations put forth by the EPA and NHTSA, that by 2018 there will be a larger market for these trucks and OEMs will begin selling 6x2s more and more.
Even though gas prices are dropping, with increasing government pressure to cut emissions, every little bit helps. The EPA’s regulations kick into effect in 2018 and they will initially raise costs. If truckers are already switching over to money saving tactics and equipment, however, it will not be a rocky transition. Things are expected to go much more smoothly with the Phase 2 regulations than previous ventures in regulating emissions. The EPA has a page with lists of companies and products that meet their SmartWay standard and you can find it here. Buyers should do some research, however. Some of these companies are offering very inexpensive products and it is quite possible their quality is as low as their prices. It would be a shame to try out a new rig and new, say, tires at the same time and not know for certain what is at fault.