Page 28 - Newcom

Equipment
Test Drive: Chasing 10 mpg
Extended run with new Mack Anthem yields excellent fuel economy – even in the hands of a novice
By James Menzies
NEW ORLEANS, LOUISIANA
With Hurricane Florence out of the way, I flew to Asheville, N.C. Sept. 17 with questions on my mind. A hand- ful of editors were about to embark on a nearly 1,000-mile test drive in the new Mack Anthem, with a focus on fuel economy.
I wondered, can I hit 10 mpg? Does turbocompounding work as adver- tised to deliver fuel savings? And how would my fuel economy stack up against more experienced driv- ers, and my editor peers? It was an insightful three-day trek that fea- tured stops in Nashville and Mem- phis, Tenn., Jackson, Miss., and which wrapped up in New Orleans, La.
The trucks, the route, the food
Who ever said a test drive can’t include a little fun? Our route with six Mack Anthems covered 940 miles over three days, and we took in some sights along the way. We also enjoyed some good grub – in fact, the tour was dubbed by Mack as the “Gears, Guitars and Grub” tour. It’s true, the barbecue in Mem- phis is tough to beat.
The fleet consisted of six Mack Anthems with some key differences. Two red tractors had the MP8-445C Maxi-Cruise engine (445 hp/1,860 lb.-ft. torque) with full aero pack- age, but without turbocompound- ing – or what Mack is now calling Energy Recovery Technology (ERT). More on that in a bit.
Two white tractors featured the MP8-HE-415SE (415 hp/1,760 lb.-ft. torque) engines with ERT, and Mack’s HE+ aero package for max- imum fuel economy. These also fea- tured a 6x2 axle configuration with liftable pusher axle.
The two blue tractors had the MP8-HE-445SE (445 hp/1,860 lb.-ft. torque) engines with ERT and the HE+ aero package. All trucks were loaded to about 67,000 lbs – a pretty typical payload.
The HE+ package features: predic- tive cruise, and a full aerodynam- ics package including a roof fairing with adjustable trim tab, an under- bumper spoiler, and chassis fairings with ground effects.
So, from those spec’s alone, you’d expect the white tractors to deliver the best fuel economy performance with the blue trucks hot on their heels and the red tractors slightly behind.
What’s turbocompound...er, ERT?
Initially introduced on the MP8 engine as turbocompounding, Mack has elected to adopt the more mar- keting-friendly term Energy Recov-
The #4 Mack with ERT consistently achieved the best fuel economy.
er-generation trucks with all the lat- est technologies such as automated manual transmissions and adap- tive cruise control. These technolo- gies are the great equalizers, which allow even a novice driver to rival the fuel economy of a veteran.
I was curious to prove my theory during this drive.
Jim Park, an editor with Heavy- Duty Trucking and Today’s Trucking, has two million miles over the road to his name. He knows how to coax great fuel economy out of whatever powertrain you want to put in front of him. The rest of us editors lack that over-the-road pedigree. You’d expect Park to blow our fuel econ- omy out of the water. But that didn’t happen.
Taking the non-ERT Macks out of the picture, there was an 11% spread in fuel economy between Park – who achieved the best overall mileage at 9.5 mpg – and the rest of us. But Park had a slight advantage. The non-ERT truck he was driving on the final leg had to be taken out of service due to a mechanical gremlin, so his mpg reflected only his time in the two ERT-equipped models. So, for fun, let’s take the 9.5 mpg driver out of the picture, as well as the driver of the other non-ERT Mack. Now we get a 5.6% gap between the best and worst drivers in the convoy.
As I suspected, the technol- ogy available from this powertrain brought parity to our small pool of drivers, while the veteran was still able to squeeze a little better fuel mileage out of the equipment than the rest of us. For a more direct comparison, Park got 10.5 mpg out of the same white Anthem in which I achieved 10 mpg on the nose. A 0.5 mpg improve- ment cannot be overlooked.
Put the technology to work for you
My goal all along was to hit 10 mpg, something I haven’t been able to achieve before. I achieved that on the final leg with truck #4, a white Anthem that consistently obtained the best fuel economy. Here are some tips that I followed to get there: I used cruise control religiously – as much as 85% of the time.
I upped the engine brake setting while in cruise by a few miles per hour in order take full advantage of the truck’s momentum on downhill
ery Technology (ERT) to describe this feature. It did so to avoid con- fusion with past applications of tur- bocompounding, which differed completely by converting previously wasted exhaust heat and turning it into additional horsepower to pro- vide a performance benefit.
Mack flipped this model upside down and instead uses the 50 or so additional horsepower generated from previously wasted heat, and uses it to take a load off the engine, improving fuel economy. It’s an effi- ciency-based concept, rather than performance-based.
“Mack Energy Recovery Tech- nology is an advanced feature of Mack’s MP8-HE engine that cap- tures engine heat that would oth- erwise be lost, converting it to mechanical energy and delivering it back to the crankshaft in the form of torque. The additional energy allows the engine to operate at 1,000-1,100 rpm, improving fuel efficiency and
life expectancy without sacrificing performance,” Phil Cary, south- east regional fleet service manager with Mack Trucks, explained to me during our drive.
“Mack ERT is not applying tur- bocompounding in the traditional manner, which has been used to add more power to the engine’s out- put, rather than to relax the engine to improve fuel efficiency and life expectancy without sacrificing per- formance.”
Mack touts about a 5% fuel econ- omy improvement in trucks spec’d with ERT. But would the trucks with ERT live up to this claim on our nearly 1,000-mile route?
Achieving fuel economy parity
It’s often said that the driver can have up to a 30% impact on fuel economy, all other things being equal. I don’t believe that to be the case anymore, when driving new-
28 Truck News • November 2018