The MP8 505C+ with mDrive is a high-performance powertrain that will likely challenge everything you thought you knew about the limitations of 13-litre engines and AMTs in Canada’s most rigorous applications.
CALEDON, Ont. — It was as nasty a November day as you’ll encounter in Southern Ontario. The thermometer read -9 C; balmy when compared to the -19 C wind chill. Snow blew horizontally, painting the horizon a milky white. Snowdrifts piled up on the road in places while the wind swept other sections of highway clear, leaving behind only a thin layer of black ice. Gusting winds caused vehicles and old buildings to shudder, as well as the people within them.
In other words, it was a perfect day to test drive a Mack truck.
The truck was a Mack Pinnacle tractor with its newest engine rating, the 13-litre Mack MP8 505C+. It was put together by Vision Truck Group as a Mack Trucks Canada demonstration unit and then loaned out to James Dick Construction. The new made-for-Canada rating, introduced in August, produces 505 hp and 1,860 lb.-ft. of torque through all the gears. In short, it’s a Mack that pulls like a Mack – all the time. It was designed for truckers who want loads of pulling power available on demand, to handle hefty payloads and steep grades.
While many of today’s engines are designed to withhold torque to preserve fuel economy under certain conditions, this engine is all torque, all the time. James Dick Construction is an ideal fleet to put the truck through its paces. It hauls heavy payloads of about 34,000-40,000 kgs around a hilly part of southern Ontario just north of Toronto. Typically, these trucks shuttle tonnes of aggregate between various construction sites and cement plants from James Dick’s many gravel pits in the area.
I shared driving duties with Murray Lowe, who the fleet has chosen to test the new truck, knowing they would get an honest assessment from the opinionated and knowledgeable pro driver. It was useful to ride shotgun with Lowe, because he could compare the driving experience directly to his incumbent truck, a 2011 Freightliner glider kit featuring a pre-emissions DD13 engine and 13-speed manual transmission. (Comparing trucks of different makes is a dubious endeavour at the best of times, even more so when the benchmark is a glider kit, which is by definition, an assemblage of parts and not a complete vehicle. Still, comparisons to the incumbent vehicle are inevitable).
Pulling the long grade leaving Bolton, Ont. Lowe marveled as the mDrive automated manual transmission held seventh gear with 32,000 kgs of gravel in the 38-ft. Cobra end-dump trailer. “I’m normally in fifth gear here,” he said.
Lowe has five million miles under his belt, achieved over a 41-year career that was spent mostly doing linehaul. I figured he’d be skeptical of the mDrive but he surprised me with how quickly he warmed up to it.
“I’ve been doing this over 40 years,” he grumbled. “What do I need to shift gears for?”
Lowe, in the twilight of his driving career, has traded in long-haul work for local, mileage-based pay for hourly. He even hands in the keys for the winter and waits the snow out in Florida. This was Lowe’s first experience with the mDrive and his only concern was how it would react when the truck gets bogged down in mud. That wasn’t about to happen on this frozen November morning but he said the guys who get stuck in the mud using an automated transmission are the same ones who can’t get free using a manual, and he’s not one of’em, so he wasn’t overly concerned.
Power is power
As we crested a long, steep downhill grade with a red light at the bottom, Lowe questioned aloud the engine brake’s ability to hold back the heavy load and then nodded in approval when it did just that.
The MP8, being a 13-litre engine, often raises questions about its engine braking capability compared to a 15L product. But it does produce nearly 500 braking horsepower, which shouldn’t be an issue, even when heavily loaded. David McKenna, Mack director of sales development, emphasized power is power, and torque is torque, regardless of whether it’s produced by a 13- or 15-litre engine.
“If I’m giving you 1,860 lb.-ft. out of a 13L, it’s exactly the same as 1,860 lb.-ft. out of a 15L,” he pointed out. “But it tends to be 300-500 lbs lighter and generally speaking, more efficient on fuel, so when we’re talking the aggregate business, if I can take 300-500 lbs out of your TARE weight, that’s nothing but money to the customer.”
Naturally, having 1,860 lb.-ft. of torque available at all times means a driver’s going to take advantage of it and at times it will come at the expense of fuel mileage. However, McKenna contends the fuel economy penalty is low, especially when compared to the productivity gains that can be exploited.
“The fuel economy with the 505C+ is going to be a little less than a straight 505C or E model,” McKenna acknowledged. “If you want more power, it’s going to take more fuel to do it. But if you can learn to keep your foot off that throttle pedal and let the engine do all the work, fuel economy is just about the same. But when you’re pulling 63,000 kgs in the aggregate business and you can reduce cycle times by 15-16 minutes per cycle, that’s an extra load every day and when you have 40 metric tonnes of product, you just managed to pick up an extra load for free every day and it’s very economical.”
Fuel economy isn’t always the top priority for truckers in the aggregates business. Here, performance trumps fuel efficiency, and heavy payloads, hilly terrain and stop-and-go two-lane traffic will see to it. Lowe told me James Dick drivers are normally resigned to hitting 5-6 mpg. Uptime is the paramount concern and the company has done its best to avoid the problems associated with EPA07 emissions engines, hence the glider that Lowe drives. But then Lowe drove his friend’s new Mack and it was getting over 8 mpg in this same duty-cycle. That got his attention.
Caledon Mountain may not qualify as a mountain in many parts of Canada, but here in southwestern Ontario it’s a good test of a truck’s pulling capabilities. We climbed it unloaded, just due to the nature of the day’s delivery schedules – hey, we had work to do and loads to deliver! Lowe was impressed the mDrive dropped just one gear and we climbed the hill in 11th at 1,475 rpm and 80 km/h. His current truck would be revving a lot higher, he observed. The nasty crosswinds and snow-covered roads likely didn’t help us on this day and even whether or not the tarp is rolled up will have an effect on how the truck pulls that grade, Lowe noted.
We picked up a load of blended aggregate at James Dick Construction and then I took the wheel and brought it down to a Lafarge plant in Brampton.
The mDrive console sits in the dash. Exposed screws provide easy access to the wiring behind.
A button on the mDrive’s console allows you to activate maximum engine braking, which was a useful way to hold my speed to 80 km/h without riding the service brakes, even when grossing 50.86 metric tonnes (50,860 kgs or 111,892 lbs). This Pinnacle drove well. The front end felt a little loose, but repositioning the fifth wheel would solve this. The seat was comfortable, sight lines were excellent and the ride on even bumpy two-lane roads – where James Dick trucks spend most of their time – was smooth and quiet.
The interior of the Pinnacle was stylish and functional. Attractive, brushed nickel faceplates can be quickly removed from the dash to expose the wiring behind them for easy serviceability. The design of the Pinnacle won’t change with the 2016 model year. The exterior styling could use a refreshing but as far as comfort and drivability are concerned, this truck holds its own against anything out there.
Most Canadian customers who previously ran the MP8 505 have switched to the C+ rating since it was introduced in August, I’m told. Even in Western Canada where these trucks are required to run the Rocky Mountains, there have been no complaints about fuel economy, power or engine braking performance. Mack has discovered a way to give 15-litre power and performance to truckers in a 13-litre package and there’s a lot to like about that, including improved fuel efficiency and greater payloads.
The cold truth about exhaust aftertreatment in winter
Because winter was visited upon us seemingly overnight, I had some questions for McKenna about the aftertreatment system and how fleets can protect against issues related to the freezing of diesel exhaust fluid (DEF) and the rest of the SCR (selective catalytic reduction) system. He was glad I asked.
“One of the things that’s very important to remember is that DEF is two-thirds water and water will freeze,” he admitted. “There are a couple of things we do that some other OEMs don’t do. When you turn the key off on the truck, you will hear the DEF pump continue to run for about 60-90 seconds. It’s drawing the DEF back from the injector and putting it all in the tank. The reason for that is, we don’t want any product freezing in the line. Even if it freezes in the tank – and it will – the minute you crank the engine and start the water pump, it’s going to start circulating hot coolant through the DEF tank. We’ve plumbed the lines into the DEF tank and we have a coil that goes through the center and we’ve looped the coil around the pickup tube, so it will thaw out from inside the core of the DEF tank to the outside and start to circulate warm DEF.”
This is a smartly designed SCR system but where problems can still occur is when sub-par DEF is put into the tank. McKenna emphatically cautions against using off-spec’ DEF.
Canada’s harsh winter conditions can also lead to more frequent and prolonged active regenerations of the DPF (diesel particulate filter). This is not a problem that’s specific to Mack – and in fact, Mack protects against this by keeping the heat source required for regenerations (the turbocharger outlet) very close to the DPF to prevent a thermal drop from occurring as the hot exhaust travels along the exhaust pipe. But in applications requiring large fuel tanks and where the hot exhaust has a chance to cool en route to the DPF where it must travel to facilitate a regeneration, you can add more insulation to the exhaust pipe to mitigate this problem.
Downtime, of course, is a killer, especially in the winter.
“I can talk about fuel economy all I want, but at the end of the day, if you save 5% in fuel throughout the year and you have two more unplanned down days, everything you saved through the year in fuel is out the window,” McKenna acknowledged.
This is where GuardDog Connect comes into play, Mack’s telematics-based maintenance monitoring system. It sends fault codes generated by Mack engines, transmissions and aftertreatment systems to a call center where they’re evaluated by a Mack expert who then advises the driver or fleet manager on the proper course of action. If the light came on due to an issue that can be resolved later, then the truck can be kept in service till the end of a shift or its next scheduled service interval. This service comes standard and free of charge for two years on new Mack trucks, including the Pinnacle I drove. Take advantage of it.
An additional benefit that’s often overlooked is that GuardDog Connect has the potential to eliminate downtime resulting from driver error, by alerting fleet managers to driver-induced problems before they require a truck to be taken out of service. For example, if the driver is using the gas pedal to keep the truck stationary on a grade, the mDrive will generate a fault code indicating an overheated clutch. If this is happening routinely it will alert the fleet manager to some bad driver habits and allow for an intervention – hopefully before the clutch is burnt out and needs to be replaced.
There are many applications where the Mack Pinnacle with the MP8 505C+ is well suited – aggregate being just one of them. This rating will fit in anywhere that constant torque is desired. Don’t be put off by its 13-litre displacement. Engineers today can coax more power out of smaller, more efficient engines.
Mated to the mDrive transmission, the 505C+ is a high-performance powertrain that will likely challenge everything you thought you knew about the limitations of 13-litre engines and automated manual transmissions in Canada’s most rigorous applications.
And it’s also just plain nice to drive. In fact, an unprompted remark from Lowe may have served as the greatest endorsement of this product that Mack could’ve hoped for.
“I was going to pack it in after this year,” he said. “If this is my new truck, I may have to stick around a while longer.”
Driver Murray Lowe drops a load of blend aggregate.
The Mack Pinnacle photographed in a James Dick Construction gravel pit.
Snow-blown Hwy. 50.
James Menzies tries to keep warm on a chilly November day.
The Pinnacle with MP8 C505+ engine rating is well suited for the aggregates business. All torque, all the time.
James Menzies is editor of Truck News magazine. He has been covering the Canadian trucking industry for more than 15 years and holds a CDL. Reach him at email@example.com or follow him on Twitter at @JamesMenzies. All posts by James Menzies