Cummins, the diesel engine specialist, has just announced a new engine for medium duty delivery trucks that runs on E85 – a blend of 85% ethanol and 15% gasoline – that can reduce CO2 emissions by up to 80%.
The Cummins ETHOS engine began life as the 6.7 liter V-8 commonly found in many medium duty commercial trucks. Working in cooperation with the California Energy Commission, they cut engine displacement down to 4.5 liters, then realized they could go smaller still. In the end, they wound up with a 2.8 liter engine that makes 250 hp and 450 lb-ft of torque – more than enough power for intended use. Those numbers equate to gasoline engines with twice the displacement.
ETHOS was developed alongside the ultra-efficient ATLAS diesel concept Cummins has been working on with the US Department of Energy. Both engines use many common parts and have similar power ratings. The ethanol engine actually uses a compression ratio similar to that of the diesel and employs advanced spark ignition technology to manage the combustion process. It also incorporates a stop/start system, which is important because most delivery trucks for spend much of their time parked at the curb or at a loading dock.
Cummins partners in the ETHOS project are Valvoline, Allison Transmission and Freightliner.
The claimed CO2 reduction is for cellusotic ethanol, which is derived from wood, grasses or the inedible parts of plants. Cellulosic E-85 is less intensive in terms of land use, tilling, fertilizing and harvesting than corn-derived E-85. It also does not divert any corn away from use as a food source for people or animals. Even when using corn based ethanol, the total CO2 reduction is still a very impressive 50%.
The ETHOS engine has racked over a million testing miles in the last 2 years. A final on-road validation testing phase began in June and will finish at the end of this month. And from there? Who knows…
Source: Gas 2.
