Each fall we review the several hundred products that we've run in Construction Equipment during the past year, evaluating each for technical advances or competitive potential that might warrant their inclusion in our Top 100 Products. You can review our choices online at the Top 100 Products of 2002 page.
This year, seven engines made the cut. This came as no surprise, because our evaluation encompasses not only the technology integrated into a new product, but also the product's effect on the market and, ultimately, on the buyer.
For on-highway truck engines, exhaust-gas recirculation (EGR) seems to be an effective means of meeting the latest EPA demand for cleaner stacks. EGR technology didn't come easily, though. Engineering challenges associated with system durability, thermal loading, variable-geometry turbochargers, and control systems that keep everything working in harmony were tough to overcome.
And, looming over all this effort was the concern about diminished fuel economy. Even that issue seems to have been reasonably addressed, however, and let us not forget the significant gains in truck fuel-efficiency afforded by past emission-control strategies—among them electronic fuel systems, charge-air coolers, and refinement of the combustion chamber and injection hardware.
Nor dare we forget about on-highway-engine emission-control strategies that employ alternatives to the EGR concept and, thereby, offer truck buyers a choice of technology. We think there's something fundamentally healthy about manufacturers standing up and advocating different technical solutions for a common challenge. In the end, the buyer obtains a better product, no matter which technology is chosen.
The off-highway side of the business, of course, has not yet been forced to attain emission-reduction levels akin to those of the on-highway side. But that said, off-highway-engine builders have invested tremendous resources in meeting the EPA's Tier II requirements, and are diligently working toward exceedingly more-stringent Tier III compliance. We've had occasion to test several Tier II-compliant machines against their predecessor models, and to our surprise and the industry's credit, we've seen fuel-efficiency gains ranging from 5 to 25 percent for the new models.
It's a judgment call, but the effort involved in producing cleaner diesels will eventually pay dividends beyond just cleaner exhaust stacks. Concern about the packaging of emissions technology may lead to overall more-efficient vehicle designs; concern about sound levels to quieter vehicles; and the never-ending quest for fuel economy, despite emissions control, to lower operating costs.