Many of us could afford to lose some weight, as we'd look sleeker, feel better and maybe live longer. The same thing goes for trucks, because lighter tare weight makes for easier driving, greater fuel economy and, if weight laws are enforced in the operating area, allows more legal payload and therefore more profit.
That's the point of the lightweight mixer chassis displayed by International Truck and Engine at the World of Concrete show in Las Vegas last January. As it sits, this truck tips the scales at 23,040 pounds, which is several thousand less than a typical 10-wheel mixer with a 10-yard barrel, according to the company's product planners.
Obviously, this truck could be filled closer to capacity than with a heavier chassis, depending on operating requirements and the state in which it runs. Weight laws comprise a whole 'nother subject which I'll mostly bypass here, except to say that they always determine how a truck is set up.
This 10-wheeler has a setback front axle, and it could theoretically operate in most states, says Bill Sixsmith and Frank Raney, severe-service product planners who had a big hand in the truck's creation. In practice, only a few jurisdictions allow a lot of concrete to be carried on three axles — New York City and the state of Texas come to mind — but we can still learn some lessons from its basic specifications.
The specs list begins with International's Paystar 5000i chassis — a 5600i, to be exact, which has the setback steer axle (a 5500i has a forward-set axle). It has a lightweight aluminum cab, which saves several hundred pounds over the 7000 series' steel cab.
Yes, the Paystar name is back after several years of disuse. It applies to the severe-service 5000i series, and is part of a revival of "star"-suffixed names that will be applied to various products in coming months. Remember Loadstar, Cargostar and Transtar? They may or may not reappear, but the Prostar, a new highway tractor due out next January, was just unveiled.
Under the big hood of this 5600i is a Cummins ISL, a heavy-duty in-line six based on the midrange ISC. It weighs about 500 pounds less than a bigger-block ISM, yet delivers healthy horsepower and torque, though the torque peak occurs at slightly higher revs than with a bigger engine.
Wait — why not use International's own DT 570, a direct competitor to the ISL? Because the 570's higher-power ratings will disappear in 2007, when stricter exhaust emissions limits take effect. So, like Kenworth, Peterbilt and Mack, International will use the ISL for lightweight heavy-duty applications.
As you can see, the 10 wheels were all polished aluminum discs, which in the 22.5-inch size save about 330 pounds versus 10 steel wheels while adding some class to a truck's appearance (this truck was built partly for show, after all). They're bolted to steel-and-iron Centrifuse brake drums, which slash nearly 400 pounds compared to iron-only drums, according to supplier figures.
You'll note from the specs box that the front and rear axles seem aimed only at strength. The steer axle's capacity is 22,000 pounds and the tandem's is 44,000 (though that's a little less than the usual 46,000-pound tandem often found on such a truck). The main frame's rails are 12 inches high and an outside C-channel reinforcer adds even more beef. So no corners were cut here in the name of weight-cutting.
The biggest weight-saver of all, though, is the McNeilus Revolution body with its fiberglass drum, which saves 2,000 pounds compared to a steel drum, according to its maker. Almost any mixer could use that, and would gain a half-yard in capacity, McNeilus advertises. The Revolution, introduced several years ago in Las Vegas, is understandably becoming popular.
A simple 10-wheeler should be an easy truck to drive, and this one was. In my experience, 10-wheelers ride rough, but this one did not. Ask Larry McCombs, a driver-mechanic at the International Technical Center in Fort Wayne, Ind., who was my guide for this drive. He rode shotgun perched on a cardboard box and a couple of pieces of foam padding, as this truck had no passenger seat — there's another 75 or so pounds saved — and the jump seat that he would've otherwise used was off in another truck.
As we cruised down the I-469 loop southeast of the city, I commented that even without any load in the drum, the truck rode pretty well, though that was easy for me to say from the smooth-working National air-ride driver's seat. "Yeah, it actually does," McCombs said, making me feel less guilty. Then again, the cab's rear sat on Link air bags, a really nice feature for a vocational truck. Because of that, and due to a generally compliant ride from the axle suspensions fore and aft, he'd not been battered on the bowed concrete streets we'd previously been over, either.
Of course, we had spent as much time standing on the ground during this excursion as driving, as it takes time to pose the truck and photograph it. Pictures of the Paystar don't show its size too well. This is a tall truck, and it was imposing the first time I approached it and began getting in. Its first step is well above the pavement and the next two are also good legfuls, but there are plenty of handles so I never felt in any danger of falling.
The feeling inside is at once spartan and deluxe. There's no doubt that this is a work truck, but it's a pleasant place to work. The 5000i is International's premium vocational series, and it shows in the roominess of the cab and how the interior is finished. Walls are covered by plastic panels, which help keep road noise out. The instrument panel is nicely laid out and attractively trimmed, while gauges and controls are businesslike yet easy to see and operate.
The windshield and windows, including a 52-inch-wide rear window, are big, so outward visibility is good. It would've been better if a peep window had been built into the passenger door, but it really didn't bother me because the mirrors were good and I was able to either see or anticipate whatever traffic came alongside.
Among the driveline specs is an Eaton Fuller 11-speed LL with a Low-Low range gear set. But because the barrel was empty, I seldom used more than two gears in Low range and was otherwise in High. The Cummins ISL is rated at 330 horsepower at its redline but could make as much as 345 in its "sweet spot," around 1,600 rpm. As you'd expect, we moved out briskly and got to cruising speed quickly. In top gear, the engine spun at an indicated 1,775 rpm at 60 mph and 1,900 at 65 mph. The engine's growl was pleasing to my ears, but not at all loud.
By the way, this truck was spec'd with a push-button starter switch, just like the old days, instead of the usual key start. That surprised McCombs and me. We also wondered why its steering column lacked an adjustment lever or pedal for the steering column, as 5000i's usually have this feature. No matter, as I quickly got accustomed to where the steering wheel was and thought no more about it.
I was further surprised by the truck's tight turning radius, but maybe shouldn't have been, as this is sometimes a byproduct of a setback front axle, even with big duplex tires. I could hang right turns from the curb lane straight into the new street's curb lane without wide swings. U-turns were also easy. The Sheppard dual power steering provided a solid feel and kept the big front tires headed steadily in whatever direction they were aimed.
While builders and owners think a lot about cutting tare from a vehicle, they seldom demand the same from drivers. McCombs is a slim guy, but as I said up front, some of us could stand to lose a little. If I could drop that 30 pounds I gained since I quit smoking more than 20 years ago, I'd contribute to the weight-saving quest. Yup, I'll get right on it.
