SIOUX CENTER, Iowa – Joel Morrow isn’t content to run at 9.8 mpg.

His average fuel economy numbers – equivalent to 24 liters per 100 km – would likely leave some fleet owners overjoyed, especially in an application that involves few aerodynamic trailers and plenty of stops to deliver furniture. But the head of research and development and senior driver with Ohio’s Ploger Transportation continues to push the envelope in the search for ways to do better.

One of the fleet’s latest tests has involved prototypes of Link Manufacturing’s ROI Cabmate semi-active suspension system. To Morrow, such a change promises more than the search for a smoother ride. A different approach to the suspension might open the door to shorter wheelbases and tighter gaps between tractor-trailers.

“There are a lot of things using this as a base that I think we can leverage,” he says. Maybe the fleet could even opt for a 40-degree wheel cut rather than today’s 55 degrees, extending the life of steer tires in the process.

To this driver, the race for better fuel economy still needs to keep comfort in mind.

“Part of the problem when you start to really focus on efficiency, the truck kind of sucks for the driver. It’s a dog when you go up a hill. It won’t do this, it won’t do that. And to a large extent their points are valid. It’s always been in the past, ‘Well, if we’re not making money, I can’t afford to pay you, so forget about that.’ There’s some technology out there that I want to apply in a different way, that I think will put a smile on the driver’s face and will keep the bean counters in the back office happy.”

It’s how he thinks the ROI Cabmate could even play a role in anti-idling efforts.

Many drivers balk at using stop/start systems because the start-ups will rock the cab and wake them with a jolt of adrenaline, he explains. “When you’re dead tired, and you’re in a parking lot and you’re in a tight spot, the cab rocks, you think somebody backed into you. You generally don’t get back to sleep after that.”

The suspension could also be an alternative to premium seating packages that might otherwise isolate drivers from a cab at the expense of a feel for the road, he says.

Engine parameters

Morrow is personally running a Mack Anthem with Mack’s HE+ efficiency package, which combines a 13-liter MP8HE engine and Mack Engine Recovery Technology, along with aerodynamic and efficiency enhancements to boost fuel economy about 9.5%.

The results are reported through a social media campaign along with Jamie Hagen of Hell Bent Xpress, with the hashtag of #Mackonomics.

But Morrow’s ongoing search to balance performance and fuel economy has also led to changes in hundreds of engine parameters at his fleet, to better align Ploger’s equipment with specific applications and routes. And the needs certainly vary between those who run regional routes with multiple stops and starts, and the longhaul over-the-road trips that he runs.

“The way that we actually shift the truck, I’d like to be proactive instead of reactive,” Morrow says of one ongoing thought process. “If we have gear ratios that give us the ability to use more than one gear at cruise speed, it enables us to think about a different way to shift the truck. It’s something I’ve never heard anyone talk about.”

He’s hardly the type to simply put it in D and drive. He runs things manually much of the time, just to test the different ideas that come to mind.

The proposed changes are exploring things like new shift logic that can be used in rolling hills. He might approach a grade at 1,000 rpm, but shift gears just before the hill to bring the engine speed up to 1,400 – maintaining road speeds along the way. “Now I’m prepped to go up the hill. It’ll charge up the hill,” he says. “I call it two-speed cruise. Not only do we progressive shift coming up through the gears, but we’re going to be proactive once we’re in the two-speed part.”

Mack has already made some adjustments at the bottom end of the shift logic to ensure the progressive shifting without skip shifting.

“It works extremely well,” he says. “The truck performs better in the hill. You’re not losing any momentum, you’re not losing rpms, you’re not trying to accelerate. Instead of making a run at the hill, now we’re changing gears.”

Lower ratios

Axle ratios are being considered as well.

“We’re looking to do some things with axle ratios that may be a little bit extreme, but I think maybe we’ve figured out some ways to make things work,” Morrow says, noting his truck is spec’d with a 2.47 overdrive.

“I’d love to be 2.31, 2.26, maybe 2.16 overdrive. Right now my truck at 72 mph is at 1,200 rpm; 2.31 puts me at 75 mph at 1,200 rpm, which is what you need out west. Right now in direct drive, the second gear down, 55 [mph] is 1,150 rpm – and that’s the magic number.

“I think average speed is going to pop, fuel economy is going to pop, drivers are going to like it in a hill, everything’s going to get better.”

The best speeds

Still, Morrow questions how long drivers would be able to cruise along in their top-end speed, particularly in the eastern U.S.

“I’ve run 72 mph back east all day long, and your average speed is still 58, 59, maybe 60. I’ve run 61 mph and my average speed is 55 – so I’m only gaining [an average of] 4-8 mph, but I’m running 16 mph faster,” he says. “For back east, Illinois, that higher speed just doesn’t make any sense.”

The higher top-end speeds can also lead to more brake applications per mile, or the need to change lanes as the truck runs up on other traffic, he says, referring to the related costs that others might overlook.

Who knows what ideas will be tried next.

“My mind,” he says, “just runs nonstop.”