Article

The ProStar Platform

With the launch of International's ProStar, we can truly see the impact of the platform approach adopted by the company back in the early 1990s.

October 2006, TruckingInfo.com - Test Drives

by Steve Sturgess, Executive Editor

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With the launch of International's ProStar, we can truly see the impact of the platform approach adopted by the company back in the early 1990s. Following a dry spell back then, with no new models for a decade and a half, International started to reinvent itself with a new product strategy, new plants and new processes.

The "platform" became the Next Generation Truck. The first model off that new platform was the medium-duty 4200 five years ago, then the 8000 heavies for regional applications. Now, with the ProStar, there's a line-haul model in what International calls its Performance Trucks. And you can bet there's more to come.

For now, though, the ProStar gets all the attention – and justly so. The new model is a whole lot more than a sleeper derivative of the 8000. It's new from the ground up, and in time will replace the 9000 Series models, except for the long-nose premiums.

To be sure, the cab shares many sheet metal parts with the other trucks already introduced. That's the idea of the platform approach, which has brought new processes and plants such as the highly versatile cab assembly operation in Springfield, Ohio. This flexible process, designed and installed by Nissan, can build all the different cab versions one after another in the same fixtures, speeding assembly, reducing cost and improving quality.

And if there is one major change in the new-look International that really needs to be understood, it's the company's cultural shift to a commitment to quality. The charge is led by Tom Baughman, vice president and general manager of heavy duty trucks, who brings an automotive quality expectation after a long career at Ford.

Baughman is rigorous – relentless, some say – in his pursuit of quality throughout the International manufacturing operation, but nowhere more so than in the Next Generation, or Performance Vehicles.

A major contribution comes from International's suppliers. In the past, automotive suppliers viewed truck manufacturers as too small a niche to occupy their production. But with the platform approach, says chief engineer Bob Weber, there's enough volume of components and sub assemblies that these new Internationals get the advantage of suppliers such as Delphi, which makes the door systems common across the platform, and Bendix, which makes the driver control module that is assembled into the new platform models. And there are many others, supplying sub assemblies all built to rigorous quality standards.

Currently, International is building the ProStar trucks to validate suppliers for new subsystems and its own production processes and only in relatively small numbers. They are also being built for customer evaluation and testing so that the company can contemplate a "flawless launch" from the Chatham, Ontario, plant in Canada early next year.

THE TRUCK

On test here is the 73-inch Hi-Rise ProStar, so called because the roof is tall enough to accommodate a 6-foot, 2-inch driver standing up from the driver's seat and a 6-foot 8-inch giant in the sleeper. It doesn't extend to the full height of the cab-top fairing, allowing for flexibility of operations hauling different trailers. Later, there will be the Sky Rise, to be introduced something like a year after the initial ProStar production begins in the spring, which will offer additional height. This would be useful in a sleeper arrangement such as a dinette where the upper bunk remains lowered for a team to sleep.

The cab forward of the B pillar is familiar, using much of the sheet metal from the 8000 day-cab models. Where it differs is in the sleeper side panels and their transition back of the doors, and the back of sleeper. Obviously the roof cap is different, too. These sleeper side panels have been engineered to offer stiffness with style. In the sides, a rising styling line adds to the strength of the panel to prevent "oilcanning," a condition where the panel pumps in and out to make for a very uncomfortable environment in the cab when the truck is running down the road. Similarly, the back panel is ribbed for stiffness and, in the latest form, has the International logo clear across the back.

All this is to minimize noise, vibration and harshness from the cab structure in a major effort to make the ProStar the quietest truck on the highway.

Other efforts to reduce noise and vibration are seen in the frame design, suspension design and tuning and cab suspension – a unique strut system that is lighter and an improvement on most current designs.

At the front of the frame is what the International engineers refer to as the Mega Bracket. It is a highly engineered computer-aided design piece that performs a number of different functions in addition to being the front frame crossmember. It supports the all-new cooling system, it is the front mounting for the all-new front suspension and steering systems, and it carries the tow hooks and the hood tilt hinges. It also supports the unique swing-forward front bumper that makes access to the engine and service points so easy.

Suspensions are new for the ProStar, designed not only to minimize noise/vibration/harshness, but also to provide best-in-class ride with precise handling. The engineers have gone to great lengths to tune the spring rates and shock absorber settings to get the optimal balance between a compliant ride and responsive handling. The objective has been good straight ahead steering precision with a flat cornering attitude and smooth response to steering input.

The initial release of the ProStar offers the in-house designed progressive parabolic leaf suspension up front, though there is also an air-ride front suspension under development.

Rear air suspension is International's own, specifically tuned for the differing wheelbase and other chassis options.

The powertrain in the evaluation ProStar was a Cummins ISX 435 with the second-generation 13-speed Eaton Ultrashift automated manual transmission. According to International program manager Jodi Presswood, the ratios in this particular transmission are gathered at the top end for good fuel economy.

Also to help the economy, the truck has been spec'd with Michelin X-One single-wide drive tires. With 3.55 gears, this equates to 1,320 rpm at 60 mph in top gear. That calculates out to 1,430 rpm at 65, a comfortable cruise, but with the torque and driveability of the '07 engines, maybe a shade taller gearing would help even more.

These options go hand in hand with the advanced aerodynamics that Presswood says have been developed in the NRC wind tunnel, in Ottawa, Canada. According to him and to Ed Melching, director of product development, International has gone to extreme lengths to test the ProStar and competitive models in this wind tunnel to measure wind average drag and show that the ProStar leads the industry in aero efficiency.

Unfortunately, our fuel consumption testing will have to wait until the truck becomes available as a production unit.

IN THE CAB

The truck is new from the ground up. In the cab, it's new from the floor up. First, the cab/sleeper floor has been designed to minimize transmission of noise through the structure. The various pass-throughs for electrical and so on are also designed for minimum noise transfer.

Where it's not new, it's still targeted at heavy-duty, like the windshield. Even though the new-platform Internationals first appeared as mediums, according to Melching, many of the cab features were designed for the Class 8 applications and the ProStar in particular. Sitting higher up in the ProStar, the great visibility that was apparent in the mediums is further enhanced. A nice touch is that wing windows are provided and on this unit, optionally open.

An all-new, unique dash offers different appearances for each of the four levels of trim available on the ProStar. The most basic has black face gauges, with very appealing ivory faces for higher series. This particular unit appeared to have a combination of different levels, with some pieces prototypes, but even so, the feel of the dash is much like that of a high quality sport sedan.

The electrical system is the heavy-truck version of the Diamond Logic multiplex system that first was introduced on the medium trucks five years ago. While the multiplexing brought a few early problems, these are in the past, so the dash and other electricals should prove highly reliable. The presence of multiplexing brings a number of features such as interlocks and inhibitors to prevent the driver from doing anything too foolish.

It is easy to get comfortable , with extremely long seat slides giving a very wide range of driver accommodation. A tilt and telescope steering column and a comfortable sweep to the wing dash mean everything is within easy reach with excellent switch location.

Building on the cab ergonomics are buttons in the center of the 18-inch steering wheel for cruise, engine brake, marker and headlamp interrupt, and radio controls (an especially nice safety feature). On the underside of the wheel are controls for auto trans overrides. Selecting manual mode allows for selection of gears in the Ultrashift, bumping up and down a gear at a time, providing the shift can be completed within the permitted rpm band.

I found these switches especially useful, as the transmission wanted more rpms for an upshift than I am comfortable using. The downside, though, is the switches turn with the wheel, so accelerating away during a turn, it is impossible to hit the buttons. As a result, you have to let the transmission have its own way. I prefer a fixed "paddle" shifter for this function.

The cab is well provided with storage, overhead and in the console. There are neat storage bins on the front side of the sleeper cabinets that handily hold binders, notebooks, personal planners and so on.

IN THE SLEEPER

The seats are nearly 2 feet apart, making for an easy step-through at full standing height into the sleeper, greatly enhanced by the provision of shift controls adjacent to the cupholders on the center console. With the spec we enjoyed, a comfortable 42-inch lower bunk and a folding upper bunk were provided. This limited the very generous available storage in the ProStar to the hanging wardrobe behind the driver's seat.

A matching cabinet on the passenger side includes a slide-out work surface. There's a 12-volt supply and antenna outlet right there for a TV that straps to the top. Overhead on each side are the neatest storage bins, with doors that rotate out and down just like airplane overheads.

On ProStars without the upper bunk, there are three per side of these bins and optional (according to trim level) hanging storage in the back wall. On all, the lower bunk tilts up on gas struts to give access to the baggage compartments and center, under-bunk storage. A unique feature in this space are available locking "safes." Two were provided in this truck, allowing for a driver team to lock their valuables away individually.

Generally, the sleeper shows a lot of thought and, likely, much consultation with drivers to provide the sort of features necessary on the road. I spent only one night in the sleeper, but I felt well provided for.

Especially nice on a mild September evening were the large opening windows, provided with bug screens and hook-and-latch curtains.

ON THE ROAD

In addition to the detailed work done on cab ergonomics, driver comfort and sleeper accommodations, International's engineers worked long and hard on making the truck quiet. We found this to be the case within the first few yards starting out from the engineering center in Fort Wayne, Ind.

Once I got comfortable, I pulled out the sound meter and couldn't believe the numbers. Accelerating through the full throttle test at 45 mph, I measured only 67 db(A). Out cruising on the highway, the needle hovered around 65, and at idle it hardly registered as noise at 53. This is outstanding, and quieter by an order on magnitude than even the Volvo VN. It will be very interesting to see how other new models like the Kenworth T660 and the Pete 389 compare, but I cannot believe they will better this figure, which is close to a passenger car noise level.

The first few miles were along busy surface streets heading for the ring road, and I found the combination of auto trans and 435 Cummins ISX worked well, allowing me to deal with the traffic in the unfamiliar truck.

The excellent visibility helps sort out what is happening with the four-wheelers, with the sloping hood allowing a short 14 feet view of the pavement to the front. The angled and low waistline at the doors gives a great view down on both sides, and pod-enclosed mirrors are finger-tip adjustable.

The windows and door locks are at the fingertips, too, with a panel located on top of the driver's door pad for convenient operation. We also found the air conditioner valuable on a couple of hot days, but it seemed to bring with it a lot of fan-on time. I mentioned this to the International engineers, and later to Cummins people, and this may have been an idiosyncrasy of this particular truck.

The 435 coped very well with the 80,000-pound gross weight combination. The Ultrashift masked the engine's capabilities somewhat, but on interstate and on rural two-lane, the transmission could be bumped up to 13th (8th over) and held there on the relatively flat going around Fort Wayne.

I would have preferred the Ultrashift to be more of an uppershift, as it seemed to want 1,500 rpms to an upshift, and the new engines are so torquey low down that in the low side of the transmission you can – and should – shift at 1,000-1,200 rpm. I remember driving an early prototype of this second-generation Ultrashift several years ago and being very pleased with its shifting performance so, again, this shift performance may have been unique to the ProStar here.

I was not in the least disappointed with the ride and handling, despite having very high expectations after the engineering briefing before heading out with the truck.

Great pains have been taken to provide good steering feel and sensitivity with excellent straight ahead stability. In steering performance, this is a very relaxing truck to drive. And there's no sacrifice in turning circle. I measured a very creditable 65-foot diameter both left and right, a quite unusual performance made possible by a wheelcut of 50 degrees.

Equally impressive was the front axle ride on the parabolic leaf springs, with the truck coping admirably with transverse bumps such as approaches to bridge decks. This was complemented by the ride quality of the International tandem suspension, which soaked up the bumps very well. But the rear suspension was also very predictable, with no squat or change of attitude in a corner. In fact, the truck has good roll control so it corners flat. This is very confidence-inspiring, and I found on-ramps could be taken at higher speeds than I am used to, greatly enhancing the speed when merging with passing traffic. Of course, the Cummins ISX and auto trans also contributed their share to this good performance characteristic.

The scope of this test did not allow for fuel economy measurement, but the excellent driver information panel in the center of the wing dash could be set to view instantaneous and average fuel use, with settable parameters and a graphic to indicate fuel performance against set targets. Using this, I found that 6 mpg was easily achievable and I'm looking forward to more extensive driving of the ProStar with '07 engines to get a better handle on economy.

Certainly, the truck should deliver, with its wind-tunnel honed shape that International says is the best in the industry. And that is after testing everyone else's trucks in the same tunnel.

OPERATIONAL FACTORS

Of course, this '07 engine installation has the requisite diesel particulate filter and the requirement to run on ultra-low diesel fuel, but that is not an issue (see the Cummins feature in this month's "Emissions Authority" column, page 126).

The daily service check and fill points have received close attention, with mostly see-through containers and fill points designed to be easy to use without spills. The swing-forward bumper – two piece in case of accidents – is simple to use, with just two over-center catches releasing it to fall forward and open up the access for driver or mechanic.

The ProStar has also been optimized for service. International says this adds up to 59 fewer shop visits over a 10-year life, contributing to its lowest-cost-of-ownership objective as well as vehicle uptime.

IN CONCLUSION

It was 10 years ago when virtually all the truck manufacturers introduced new models, many for the 1998 emissions change. Now for 2007, there are several new trucks coming along, with the ProStar first to break cover.

But the ProStar is no knee-jerk reaction to accommodating the '07 engines. It is the result of the decision to take the platform approach and has been part of a long-range strategy for nearly two decades. The results show just how much preparatory work has been done to lead up to the truck's launch.

Those other trucks are coming, but for sure, they'll have to be awfully good if they are to do what the ProStar can.

It is a driver's truck, with quiet and comfortable interior and great ride and handling. It is an owner's truck, too, with built-in low maintenance and a quality commitment that should guarantee maximum uptime.

The ProStar is also a very attractive truck. And the beauty here is way more than skin deep.

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