TORONTO – Vocational trucks are getting more fuel efficient, and save for the drop in your fuel bill, you probably hardly noticed.

In calendar-year 2013, when the first round of the mandated CO2-reduction regulations (or fuel-efficiency improvement, same difference), known unofficially around the biz as GHG14, kicked in, on-highway equipment started rolling off assembly lines with low-rolling-resistance tires, more aero treatment, idle-reduction timers, and more. The builders of vocational equipment, while subject to the same rules, didn’t really have any of those options to help them get compliant with the new rules.

Low-rolling-resistance tires are great on a highway, but not so great on a muddy job site. Aero treatment? Please see above. And as for features like idle-reduction, it works in some cases, but not so well in others, like concrete mixers. If that barrel stops turning, you just bought eight cubic yards of solid rock.

There were fears in the weeks and months after the regs were announced that truck makers would start pushing customers into trucks they didn’t want because they needed to generate corporate average fuel economy (CAFE) credits. That didn’t happen, either.

“There’s flexibility in the regulation so customers can still pick and choose the technology they want,” says Courtney Guzlas, chief engineer greenhouse gas, at Navistar. “The EPA allows averaging. Not every truck has to be compliant, but every truck has to be certified, and that really turns into compliance. I think as an industry we did a good job of getting the regulators to understand the differences in the way trucks are used, and thus, amend their compliance requirements accordingly.”

But one thing the on-highway trucks share with the vocational units is a compliance label. Trucks will have a compliance label on the door indicating what GHG-reducing technologies were on the truck when it was delivered, and those bits will have to remain on the truck for the useful life of the vehicle. Useful life is defined as 435,000 miles for Class 8 vehicles, 185,000 for Class 6 and 7, and 105,000 miles for Class 3-5.

You can still paint the truck any color you want.

Most of the truck and engine manufacturers were ready with GHG14 engines long before the deadline, and that’s really the only difference we see in most vocational trucks – and who could argue with improved fuel economy? But with vocational truck users, fuel economy is often a secondary consideration to the general robustness and durability of the chassis.

“Fuel economy is difficult to measure on construction and vocational trucks,” says Mack Truck’s construction product marketing manager, Stu Russoli. “There’s a lot of start and stop driving, a lot of necessary idling, and every day on the job brings a new and unpredictable driving challenge. It’s not at all like driving straight down the highway for 10 hours a day.”

Russoli told Today’s Trucking that there have been advances in the gear-fast, run-slow approach where it made sense, and the MP8 engine platforms were certified for GHG14 with roughly a two-percent gain in fuel efficiency.

“We are always looking at weight reduction as well, which was part of the compliance options for vocational trucks,” he says. “But really, you can’t start stripping weight from a chassis that’s often built for strength. We’ve made some changes there, like offering aluminum wheels as standard, and promoting the m-Ride suspension, which is lighter than our camelback suspension. At the end of the day, weight reduction is also a competitive advantage for us. It’s a selling point.”

A couple of the OEMs, however, did bring some aerodynamic styling to the table -Kenworth with its T880 and Peterbilt’s Model 567 are both more aerodynamic than their predecessors, so that didn’t hurt them.

“Peterbilt took the opportunity with the design and launch of its vocational flagship Model 567 to incorporate fuel-efficiency enhancements, including improved aerodynamic styling, optional fairing packages, idle reduction technologies and tire pressure monitoring systems,” says Charles Cook, Marketing Manager for Vocational Products at Peterbilt. “We also retained some lightweight, fuel-saving features such as an aluminum cab and aluminum crossmembers.”

More Value Added

A year prior to the launch of the GHG14 fuel-efficiency requirements came a mandate for very advanced on-board diagnostic systems (OBD) for heavy trucks. While the industry was more than a little leery at first, several OEMs have turned that sow’s ear into a silk purse, called remote diagnostics, or some variation on that theme. So advanced is this technology that the truck can tell its owner what’s wrong with it before a failure has even occurred.

“The ‘check engine’ or the malfunction indicator lights on the dash don’t give the driver much information about a problem,” says DTNA’s J.P. Davis, segment manager for the 122SD line. “When a truck is on a job site pouring concrete or doing a lifting job, that light can cause a lot of anxiety. Our Virtual Technician can alert the fleet and the driver to a mission critical problem or just an annoying sensor issue. If the problem is a minor one, they can keep on working.”

And the diagnosis is basically instantaneous; no three-day wait at a dealership.

“We can analyze what’s wrong with the vehicle, and then send the truck to a nearby dealership for service, and we’ll have the parts and techs ready for the truck when it gets there,” says Frank Bio, Director of Sales Development, Specialty Vehicle & Alternate Fuels at Volvo Group North America. “The dealer doesn’t have to plug it in again because we already know what’s wrong with it.”

If there’s a perceived downside to OBD, it’s that the regulations require certain emission-related components and software systems to have internal coding called CAL-ID/CVN, so that the installation of unapproved parts or tampering with the system is recognized. No action is needed if the correct parts are installed.  If, however, incorrect parts or software are installed, engine performance could be affected. 

But heck, if you’re getting fuel economy back with the GHG14 engines, is there still a need to remove or tamper with the emissions system?

One of the interesting offshoots of the new engines and their more complex fuel-injection strategies and higher injection pressures is a quieter engine. There’s nothing wrong with that, but now other stuff that traditionally makes noise in the cab is more noticeable, and that has actually given rise to complaints about stuff that nobody could hear before.

“The Paccar MX13 engine runs about 4dB quieter than its predecessor,” says Kenworth’s Vocational Marketing manager, Alan Fennimore. “Because other sources of noise became more obvious, we took all the non-essential air switches out of the cab and we use an electric switch to run an externally mounted air solenoid.”

Even the engine mounts, cab mounts and firewall designs changed in response to customer comments about ‘new’ noise that was always there but masked by the engine. It’s funny what customers notice about new trucks.