Diesel Engines Key Terms

Turn the grumble into a purr when you understand diesel engines key terms

By John Williams, Business Writing and Research

Most people hear “diesel” and picture the stereotypically noisy, belching heavy-duty diesels you get stuck behind in slow traffic. Today’s technology has relegated those machines to dinosaur status: the sluggish, noisy smoke factories replaced by quieter, smoother running vehicles with increased power and fuel economy, far lower emissions, and drivability comparable to gasoline-powered engines. If you're looking to upgrade your current fleet of diesel trucks, or are considering a diesel vehicle, familiarize yourself with some key terms that demonstrate how manufacturers have applied the latest technology to make diesels a far more desirable powertrain alternative than ever before.

Biodiesel

While switching from petroleum-based fuel to fuel created from renewable resources such as vegetable oil may be good for the environment, consider the trade-offs before fueling your engine worth biodiesel, whether pure biodiesel (B100) or a petro/bio blend (commonly rated between B5 and B20). The chemistry of biodiesel fuels differs from its petroleum counterpart, affecting the engine's emissions controls; furthermore, that chemistry includes a natural solvent, which can dislodge old petrol-based deposits anywhere from the fuel tanks to the combustion chamber, and even have a corrosive effect on fuel lines.
Try: BDPedia.com outlines several shortcomings of biodiesel, including those listed above, plus potentially greater expense due to higher cost than regular petrol diesel and slightly lower fuel mileage.

Low sulphur

Crude oil in its natural state contains sulphur, which contributes to the soot you see in diesel exhaust. Since low-sulphur diesel (LSD), defined as 500 parts per million max, and ultra-low-sulphur diesel (ULSD), defined as 15 parts per million max, generate far fewer particulates, they help diesel engines meet more stringent emissions standards. By 2011, all diesel fuel will be ULSD.
Try: The Environmental Protection Agency (EPA) site helps diesel owners and fleet managers understand the transition to ULSD, plus links to retrofit programs for older diesel engines and emissions standards.

Common rail injection

Common rail injection uses extremely high-pressure pumps that force fuel into a tube (the rail), that in turn feed individual injectors controlled by an electronic black box that monitors the combustion process, emitting several short, controlled bursts of super-fine mist, providing uncommonly high levels of fuel efficiency, reduced emissions, and lower sound levels.
Try: Swedespeed outlines a history of common rail injection.

Charge cooling

Charge cooling, or intercooling, lowers the temperature of intake air after it's been compressed by the turbocharger. Cooler air drives more of the air-fuel mix into the chamber for more power, at lower overall operating temperatures.
Try: Allard Turbo Sport gives a detailed account of the benefits charge cooling offers to diesel engines, including more power and economy, lower stress from heat, and lower exhaust emissions.

BlueTec

BlueTec or BLUETEC refers to manufacturer efforts led by Daimler AG to reduce nitrogen oxide. Individual manufacturers pursue variants to the general technology, such as combine catalytic converters with particulate filters.
Try: Detroit Diesel explains why it chose Selective Catalytic Reduction (SCR) technology, which converts nitrogen oxide into nitrogen and water vapor, as its primary BlueTec emissions solution.

ACERT

Caterpillar has invented Advanced Combustions Emissions Reduction Technology (ACERT). Caterpillar proactively controls the entire combustion process, using advanced valve train design, more precise fuel metering, turbochargers with waste gates to bleed off excess pressure, and advanced electronics managing the process.
Try: Caterpillar talks about its lead in ACERT technology for its diesel applications.