Mack has purified the pedigree of its Super-Liner and Titan flagships with the long-awaited launch of the big bore MP10 engine. STEVE BROOKS puts the biggest bulldogs through a roadtrain run and comes away convinced that Mack is well and truly back in the big time.
It’s a strange thing, irony!
Like, there we were, two old school truck journos, a couple of Mack’s people, and a pair of big bangers. Not just any big bangers either, but the highest powered road going brawlers to ever roll out of the kennel.
Anyway, as I was saying, there we were in a roadtrain yard on the northern outskirts of Port Augusta, about to climb behind the wheel of Mack’s latest and possibly greatest when it struck me that I’d been in this same dusty, windswept yard years earlier. It was, I think, around early ’97. Yet still firmly ingrained in the brain box from that time is the sight of a Super-Liner with three trailers hooked on, the hood up, a big box of tools on the ground, and a bulk of a man in singlet and shorts contortioned between wheel and engine, his Redwing boots blackened by oil.
Not quite visible but just as memorable was the aural cloud of fierce invective enveloping man and machine. His arms sleeved in the slimy grit of oil and dust, this was no happy chappie and anyone within a hundred metres knew it. Right then and there, spanner clutched in his hand like a loaded weapon, the fury and frustration were palpable, totally and perhaps irrevocably pulverising the pride and passion which had first provoked ‘610’ to be painted in big, bold numbers across the top of the hi-rise sleeper.
Someone, either brave or brainless, asked, “You right? You need anything?”
“Yeah, a f***** match!”
The thing is though, back then the 610 Super-Liner was Mack’s mightiest machine and for sheer grunt, there was nothing to match it. At 16.4 litres, the venerable V8 then known as the EA9 was punching out monster numbers; 610 horsepower (455 kW) and for that time, a mind-blowing 2050 lb ft (almost 2800 Nm) of torque. Like I said, there was really nothing to match it and as Mack’s local masters had intended, roadtrain runners were particularly quick to embrace its extraordinary ability to pull like no other.
The trouble was, it didn’t keep pulling. Put simply, Mack had made the decision to blow the competition out of the water by catapulting the V8 into a new but unknown frontier – 600 plus! Unfortunately, the only thing to blow was the engine. It was just one tweak too many and the twin-banker which had done such an inspiring job for so many people at lesser ratings went from hero to hand grenade in spectacularly short time.
Soon after, the increasing stringency of US emissions regulations were offered as the reason for the end of the V8’s ongoingdevelopmentand according to veteran Mack insiders, the last EA9 610 was fitted in Australia in 1998. Mack Trucks Australia was, in fact, the last in the Mack world to use the burly V8 and looking back, it’s perhaps sad that an engine which had largely done a good job over many years should be remembered for an unfortunate performance at the very end of an otherwise long and distinguished career.
And therein rests the irony. Some 15 years or so after witnessing just one graphic example of the demise of Mack muscle in the biggest bulldogs, here on the same slab of South Australian dirt was the opportunity to experience the long-awaited rebirth of a couple of purebred dogs with more bite than ever before.
Only this time, unless there’s some malady as yet unmasked by the years of intense testing and severe standards imposed by the joint efforts of Mack and corporate parent Volvo, it’s a bite that won’t let go.
* * * * *
It’s called the MP10, it’s an in-line six displacing 16.1 litres, and it comes in two performance ratings stretching from 600 hp (441 kW) with 2065 lb ft (2800 Nm) of torque, to 685 hp (515 kW) with a stump bustin’ 2300 lb ft (3150 Nm). What’s more, it uses an SCR (selective catalytic reduction) emissions control system and because of its prodigious torque output, the 685 rating is only available with Mack’s mDrive 12-speed automated transmission. According to some, including a few within the Mack camp, it’s also an engine long overdue.
The fact is though it’s now here and ready to rumble, bringing with it the title of the most powerful engine in the conventional class, by a long shot. Indeed, the only engines outgunning the MP10 on the Australian heavy-duty truck market are both Swedes; Scania’s 730 hp V8 in its R-series flagship and Volvo’s 700 hp FH16. For what it’s worth, in Europe Volvo has now knocked Scania off the horsepower mantle with a 750 hp version of its 16 litre engine but from our enquiries there appears little likelihood of the 750 seeing the light of an Australian day. It is, we hear, a rating squarely aimed at keeping the ‘most powerful truck’ trophy locked in the Volvo vault.
It’s no secret, of course, that the MP10’s foundations are derived from basically the same cast as Volvo’s 16 litre powerhouse but as Mack principals at every level are extraordinarily quick to point out, the similarities are few and far between. Indeed, the message comes across loud and clear: The MP10 is a Mack engine, not a Volvo clone. As one Mack disciple recently emphasised, ‘For starters, Mack runs a 12 volt system and the Volvo’s 24 volt, and they don’t even use the same turbocharger. The Volvo engine has a VGT (variable geometry turbocharger) but the MP10 uses a standard wastegate turbo, so there’s no way you could slip the Volvo engine into a Mack, or the MP10 into a Volvo. They share the same displacement but that’s about it.’
There is, however, another thing they have in common, and that is a huge amount of local testing which in Mack’s case stretches back to at least 2007 when early versions of the MP10 were quietly seeded into test units around the country. In addition to its own testing though, Mack was also able to draw on Volvo’s earlier FH16 test program which left nothing to chance as it went all out to bury the memory of its initial efforts with a 16 litre displacement.
However, these weren’t the only assets available to Mack as it progressively ticked all the boxes in readiness for the MP10’s introduction on the local market. For example, current Super-Liner and Titan models use a radiator with a sprawling frontal area of more than 1750 square inches, designed to cope with the high cooling requirements of the EGR (exhaust gas recirculation) emissions system used on the 15 litre Cummins ISX engines which have been the prime power source under both Super-Liner and Titan for most of the past decade. What’s more, the MP10 actually started life in North America as an EGR engine but with Mack Australia’s decision to wait and opt for an SCR system with its inherently lower cooling requirements and subsequently higher horsepower potential, the Mack engine is said to have a huge amount of cooling capacity, with plenty in reserve for hauling heavy roadtrain weights through scorching summer temperatures.
Also on cooling, the MP10 uses an electronically actuated Behr viscous fan clutch which apart from being almost totally imperceptible in operation, works according to actual need by delivering anywhere from five to 95 percent of fan engagement. Put simply, rather than being either fully on or fully off, the fan responds with incremental engagement dependant on the amount of cooling assistance required.
Furthermore, the arrival of the MP10 certainly doesn’t mean the end for Cummins in Super-Liner and Titan chassis, with Mack wisely opting to offer both engine families. In Super-Liner, for instance, which caters for gross combination weights (GCW) up to 145 tonnes, the MP10 is available at both 600 and 685 hp ratings while the ISX is offered at ratings of 525, 550 and 600 hp with peak torque set at 1850 lb ft.
On the other hand, the heavier-duty Titan with gross weight ratings starting at 131 tonnes and maxing out around 250 tonnes, sees the MP10 offered alongside ISX ratings of 550 and 600 hp available with the choice of either 1850 or 2050 lb ft torque peaks.
Still, it doesn’t take a marketing guru to realise that the big push and indeed the big interest will be in Mack’s new hardware. As already mentioned though, the MP10 685 rating is only available with Mack’s mDrive 12-speed automated shifter which, like its I-shift counterpart in Volvo’s FH16 700, is the only multi-speed transmission in the stable able to cope with the mountain munchin’ 2300 lb ft torque output of the 685 engine.
As for the 600 hp model, mDrive is optionally available along with manual shifters including two versions of Mack’s own triple countershaft 18-speeder and Eaton’s heavy-duty RTLO-22918 18-speed.
Meanwhile, the undercarriage sees a typically wide selection of rear axle options feeding grunt to the ground, mounted on either Neway or Hendrickson airbag suspensions or mechanical layouts including Mack’s ageless camelback assembly.
In Titan, for example, there’s the choice of four Mack rear axle combinations including hub-reduction and specialist tri-drive assemblies in capacities ranging from 26 to 44 tonnes, along with two versions of Meritor’s popular RT52 tandem rated at 24 tonnes, Dana D50 and D52 tandems at 23 and 24 tonnes respectively, and Sisu combinations in 26 tonnes tandem and 39 tonnes tri-drive formats.
Super-Liner doesn’t offer quite the same array of back-end options but nor is it short on choice with Mack, Dana and three Meritor assemblies available with capacities ranging from 21 to 24 tonnes.
In such top tier toilers, the full list of cab, sleeper, chassis and drivetrain options is obviously extensive and far too detailed to list here, but the specifications of the Super-Liner and Titan provided for this exercise perhaps typify the bulk of modern roadtrain applications.
Although configured as a roadtrain double hauling tippers and loaded to a gross weight of around 80 tonnes, the Super-Liner was in fact specified for roadtrain triples livestock work, built to a GCM of 130 tonnes and fitted with a 52 inch hi-rise sleeper. Under the snout, the MP10 was set at the 685 rating and therefore attached to the mDrive 12-speed automated transmission. The undercarriage saw a Mack steer axle mounted on parabolic springs and a Meritor RT 50-160 drive tandem running a 3.9:1 final drive ratio mounted on Neway’s AD246 airbag suspension. Four square tanks had the capacity to carry 1650 litres of fuel while sitting between fuel tanks on the driver’s side was a 150 litre AdBlue tank, with 125 and 200 litre tanks also available.
With a GCM of 140 tonnes, the Titan was specified for what Mack referred to as ‘roadtrain distribution’ work and fulfilled its role by hauling three curtain-sided trailers supplied by South Australian company Cooke Plains Gypsum. Also fitted with a 52 inch hi-rise sleeper but loaded to a gross weight around 110 tonnes, the Titan was punched by the MP10 685 rating but differed from the Super-Liner with a Mack multi-leaf spring pack under the pointy end and a Meritor RT 52-185 tandem running a 4.3:1 diff ratio bringing up the rear on Neway’s heavier capacity AD260 airbag suspension. Total fuel capacity was also greater at 1950 litres but AdBlue capacity was the same at 150 litres.
Meanwhile, under the hood it’s a neat fit with the considerable bulk of the engine easily housed and generally providing good access to regular service items, particularly compared to an EGR engine with its multitude of add-on components.
So now it’s time to climb aboard … except for one matter which some operators are sure to ask: How come Volvo rates its top toiler at 700 hp and Mack at 685 hp when they both use a 16 litre engine with an SCR emissions system and run the same peak torque output?
Well, according to several Mack sources, the answer has absolutely nothing to do with corporate competitiveness and everything to do with engineering formulae. As we reported in our previous issue, the difference is ‘… nothing more than an academic aberration derived from the different methods used by European and American engineers to rate engine performance.’
Or as one Mack man succinctly put it, ‘Have no fear, the 685 will pull as hard as any 700 in the business.’
And so it was!
Muscle & Manners
The run was simple enough … north up the Stuart Highway to Pimba, turn right to Woomera and on to Roxby Downs, then back to Port Augusta. All up, not much more than 500 kilometres. Still, it’s a run with a few notable climbs, particularly northbound and particularly the last long drag before Pimba where the 685 made a mockery of both road and load.
It’s no good beating around the bush; the Super-Liner double ran up the Pimba climb dropping just one gear, the Titan triple pulling back to just 9th slot, and by any measure, performance of the MP10 685 in each configuration was absolutely outstanding. As the title of this report states without apology or apprehension, it was in every sense a ‘Macknificent’ performance.
But it’s not just the way this engine performs, it’s the way the performance is delivered. Sure, there will be those who will rue the absence of a manual shifter behind the 685 and perhaps the only disappointment of the whole exercise was that the Super-Liner double combination wasn’t powered by the 600 rating with an 18-speed stick shift. It certainly would’ve made an interesting comparison.
However, such wasn’t the case and the compatibility of engine and automated transmission in both configurations was truly exemplary. Here’s an engine, for example, which at the 685 setting produces peak power from 1550 to 1800 rpm and maximum torque from 1000 to 1550 rpm, married to a transmission programmed to let the engine pull down deep into the rev range before downshifting, while at the other end of the scale, upshifting surprisingly early to maximise the engine’s phenomenal pulling power. Nor, of course, will these traits do anything to harm fuel efficiency.
Simply put, Mack has nailed it.
Still, the story doesn’t end there. The MP10 also boasts a surprisingly effective ‘PowerLeash’ engine retarder, dispensing up to 570 hp (425 kW) of engine braking effect at 2200 rpm. Sure, it’s not in the same class as the engine brake performance of a 15 litre Cummins but by manually shifting down a gear or two to keep revs up, it’s an engine brake capable of delivering effective retardation even at weights beyond 100 tonnes.
On the other side of the coin though, there are some aspects of Super-Liner and Titan which left something to be desired. It could be argued, for instance, the doors don’t open wide enough for bigger blokes, and the engine cowl overly restricts space for the driver’s left foot. That said though, steering, ride quality and low noise levels all rated highly.
Finally, there’s no hiding the fact that this was just one short exercise and ultimate judgement will come from the operators and drivers who will steer Super-Liners and Titans punched by MP10s in heavy-duty hauls around the country. But if first impressions are anything to go by, Mack has compiled a truly potent package which in performance terms has no equal in the top end of the conventional class.
The dog is well and truly off the chain.