Back in 1980, at a rest stop in the Pacific Northwest, I met a couple of guys from New Jersey who were long-hauling in a Mack – with no sleeper. It wasn't legal and they knew it, and it certainly wasn't comfortable, sleeping upright on the passenger's seat as the other guy drove the hard-sprung tractor down the interstates.

But "back East," Mack was king of the road, and their mid-'70s R model, bought used, was what they could afford. It delivered good fuel economy with its Maxidyne diesel and straight five-speed transmission. They did plan to have a small sleeper box installed after they got back home, and who knows how long they roamed the roads in that truck?

Those guys from "Joisey" would probably be pleased to wake up in this non-sleeper Mack Granite tractor, with its wide, roomy cab, modern instruments and controls, and a comfort level they wouldn't have believed. Of course, the Granite is more truck than they'd have needed, as it's a severe-duty model meant to pull not dry vans or reefers but lowboys, end-dumps and other stuff that leaves the pavement.

This is not your father's Mack

The Granite tractor is the third model in the on/off-road series, introduced last year as two straight trucks: the western-style Granite Bridge Formula with lightweight components and long wheelbases, and the slightly shorter and more hefty Granite for most eastern and midwestern states. The tractor can be set up for any state in axle spacing, frame and other details.

Granites use extra strong frames and share integrated electronics designs from the highway vehicles. Its cab looks like it came off a medium-nose CH or the long-nose CL, but it's reinforced to take twisting and battering forces encountered off-road. Mack spent $17 million strengthening the CH cab for severe service. "It's the strongest cab Mack has ever built," said Steve Ginter, vocational program manager, who showed me the tractor.

The cab has big windows and doors, a lot of interior space, excellent instruments and good controls, pleasant interior appointments and a smooth ride. These attributes, plus what's in the chassis, make the Granites so advanced from the RD/RB/DM that one has to wonder why Mack customers would even consider the old models any more. Here's why: they're rugged and reliable, and it will take a while for the Granite to earn the same reputation.

The premium-level interior trim matches the look of many luxury cars, yet retains a big-truck feel. There are pockets in the doors and nooks in the overhead console for storage.

Cup/bottle holders are just below the dash, and between the seats is a roomy chest with a power point to support a laptop PC or small cooler. The AM-FM-cassette radio is handily placed in the dash; heater and air-conditioning controls are just below, and have familiar twist knobs.

Big rocker switches are easy to punch, once you figure out the "international" pictograph labels. Mack's gauges, particularly the speedometer and tachometer, are large and legible – the best in the business, in my opinion. This tractor had the Vehicle Information Profiler (VIP) electronic display that's linked to the Vehicle Management and Control (V-MAC) electronics that run the engine and other systems. You can get all sorts of operating info and diagnostics help by scrolling through the luminescent display.

There is one throwback: a roof air vent. "The RD has a roof air vent, so we put one in the Granite because we figure operators will ask for it," Ginter explained. The pop-up vent increases airflow through the cab, but just remember to button it down when you run the air-conditioning.

Gutsy engine, good view

Driving this Granite was a lot like wheeling a Vision. With windows up, outside noise was muted. The Granite's huge windshield revealed a wide view of the world, and the steeply sloped hood let me look closely at the pavement just ahead. Cut-down side windows in both doors, plus a peep window in the right door, show what's happening alongside.

This tractor had a pre-October E-Tech 460-hp diesel, which is a wonderful engine to drive – lots of power and torque, and with Mack's latest 18-speed there is never a situation where there's no transmission ratio to handle it. We towed a special Rogers trailer that resembles a container chassis with big, heavy concrete blocks; these ballasted the rig's gross combination weight to just about 80,000 pounds, Ginter said.

The trailer is not licensed for the road, so we stayed on the test track that surrounds the tech center in Allentown. There was enough room on the track for me to get up to about 55 mph for short bursts, and plenty of opportunity to go up and down through the gears.

The T318L 18-speed has a low-inertia shaft design that allows clutchless float-shifting, with little or no practice. Mack's public relations counsel, Mike O'Neill, got in and drove it away, even though he'd driven only one big rig before, and it had an Eaton AutoShift. He was like a kid with a new Tonka truck.

As with a Fuller 18-speed, the Mack tranny consists of a 9-speed main box with a 2-speed splitter. You can split every main ratio or none of them, depending on conditions and your preferences. I tended to split most gears just for the fun of it, but on the level it often makes more sense to avoid the splitter. Accelerating downhill, you can upshift at low revs, using only the main gears and letting gravity do the work.

Climbing uphill, the splitter allows you to quickly step your way through the ratios. Less RPM drop between each ratio lets you accelerate when you'd otherwise have to stay in a gear right up to redline, for fear of losing revs and momentum as you try to grab the next higher gear.

No matter what you do with the tranny, the E7-460 has the "grunt" that both accomplishes a heavy hauling job and enriches the driving experience. As a bonus, the engine makes a throaty exhaust note. Come October 1, Granites will get Econodyne or Maxidyne diesels with internal exhaust-gas recirculation. The lighter Cummins ISL is also available.

The Granite tractor's ride is smooth and shock-free, thanks to considerable development work on the chassis and the air bag/shock absorber suspension at the cab's rear. This, too, sets the Granite apart from the R-based tractors and trucks, and ought to hasten the old models' demise.

It's not likely you'd buy a Granite tractor to run up and down the highway, as its Maxidyne or Econodyne diesel with internal EGR would use more fuel than MaxiCruise diesels that will go in highway vehicles. Engines in CHs and Visions will use Mack's more complex cooled EGR system, but at cruising speeds will be as much as 5% more fuel-efficient than the I-EGR'd diesels. And you can't get a sleeper on a Granite, which might be OK for those guys from Jersey, but certainly not for you.

The Granite shows every indication of being as rock-solid as its R-based models, but delivers its driver from the cramped confines and rough ride that heretofore came with signing on to a dumper or mixer fleet dominated by Macks. If you see drivers in Granites, you can now envy them.