It’s a myth that aerodynamics won’t benefit day cabs.
That message came through loud and clear today during NACFE’s presentation of its latest confidence report on aerodynamics.
NACFE Executive Director Mike Roeth announced at the Long Beach Convention Center during ACT Expo that the non-profit’s latest fleet studies reveal that aerodynamic devices on day cabs result in fuel efficiency gains, even though the trucks frequently travel below 50 mph and do not travel the same distances as their long-haul counterparts.
And with more day cabs on the road, Roeth said NACFE is challenging OEMs to make additional aero devices standard on the regional haulers.
“We studied day cabs. This is where we put a lot of our focus, because some will say that day cab tractors should never get aerodynamics. People say that they don’t drive very fast. They don’t travel many miles and aero’s not very appropriate. We think differently,” Roeth said.
“We found as we talked to fleets that, first of all, the myth that they don’t work is untrue. Aerodynamics help at any speed. It does help at higher speeds. So, if you’re in the 50 to 60 to 70 mph, of course aerodynamics helps more.
“What we found in day cabs is that if you remove all of the aerodynamics from a day cab and really go non-aero versus total aero on a day cab, that’s worth about 10 percent as well on fuel, maybe even more.
“We found a couple of fleets, and some truck builders tell us that it was more like 13 percent fuel reduction in a day cab. Not all day cabs do get those miles that would justify aero, but we think that many more should be buying it.”
Duration of ownership is another factor worth considering when looking at aero for day cabs, Roeth said. For instance, day cabs are on the road longer. It’s not uncommon to see these regional work horses traveling for 10, 12, 15 even 20 years. During that long span of time, fuel price fluctuation can have an even greater impact on the cost of ownership.
“As we’ve seen with fuel pricing, if you go back 10 years, we had $1.50 diesel. That went to two, three, four dollar diesel for a number of years and now it’s back to two,” Roeth said.
“My point in that is that when you buy a day cab tractor, you’re not just buying it for the fuel cost of today, but for the fuel cost over the next decade. And so with aerodynamics, you’re limiting a risk there.”
As product distribution changes, Roeth said day cabs are becoming more popular.
“Day cab production as a total percent of class 8 tractor production is inching up,” he said. “It’s a higher percentage of the overall build. So aero on day cabs, we think, is a big opportunity.”
Of particular interest are natural gas day cab trucks. Owners taking a hit on natural gas fuel economy versus diesel, are losing even more fuel efficiency by not equipping their alt fuel trucks with aero devices.
Roeth said he was pleased to see more CNG storage tanks at ACT Expo with improved aerodynamic designs.
“We’re in a situation where the natural gas already has a lower fuel economy than diesel. Not having aerodynamics on those day cabs, hurts fuel economy again,” Roeth explained. “Something on the order of about a mile per gallon or more reduction. Half of that, we found, might be the day cab effect rather than just CNG versus diesel.”
NACFE’s advice to manufacturers is to lower the total cost of ownership for aero devices because with greenhouse gas effects and possibly higher fuel prices coming the need for aerodynamics will increase.
“In the middle of that, one of the findings our report is actually a challenge to those aerodynamic component manufacturers, natural gas tank manufacturers, truck builders themselves, to offer those aerodynamics more on day cabs, make it more of the standard like we see on sleepers and help the fuel economy of all these trucks,” Roeth said.
NACFE reports that aerodynamics for long-haulers have matured so much that buyers need not be concerned about their efficiency.
“When you go buy a sleeper tractor from one of the OEMs they will bring you the best fuel efficient tractor, what they want to offer to you. And you don’t need to go any further. Buy that truck; you’re going to be happy with it,” Roeth said.
“But one of our findings is that it doesn’t work for everyone. And so if you start removing some of those features from sleeper tractors, you’re going to lower the fuel economy by as much as 10 percent. So be careful in doing that, is our advice with this report. Do it only if it’s necessary or required.”
Access the full report at www.truckingefficiency.org.