Top 100: Marching to a Different Drum

Working to build diesel engines that comply with 2004 emissions standards, Caterpillar developed its ACERT technology, which attains the goal by refining air-management, combustion and electronics systems, combined with catalytic-converter after-treatment. The result, says the company, is a proprietary technology, used only by Caterpillar, that provides effective emissions control without compromising fuel economy, performance, reliability or resale value. ACERT technology incorporates 247 new patents.