The Cummins C8.3G was introduced in late 1995 and made available for buses in the first quarter of 1996. The C8.3G is a six cylinder, 8.3 litre, intercooled natural gas fueled engine with a water-cooled, wastegated turbocharger.
This new engine features advanced Electronic Control Module (ECM) with a closed-loop air/fuel ratio management system. This control system helped to optimize engine performance while controling emissions. The C8.3G also features the Cummins Ignition Control Module (CIM) and Governor Control Module (GCM). The GCM allows for a throttle inhibitor (vehicle door interlock), power take-Off (fast idle), fault detection, cruise control, and road speed limiter. The C8.3G utilizes lean-burn technology which allows cooler combustion temperatures, and thus reduces levels of nitrogen oxides (NOx). The lean-burn air-to-fuel mix also allows a more efficient fuel energy to work.
The C8.3G will meets the 1996 California Air Resources Board (CARB) emissions standards, CARB's low-emitting vehicle (LEV) requirement, the EPA's 1997 emissions standards; all without the use of an exhaust catalyst. With the use of an oxidation exhaust catalyst, the C8.3G will meets the 1998 CARB ultra-low-emitting vehicle (ULEV) emissions levels. The oxidation catalyst reduces unburned hydrocarbons, carbon monoxide emissions and particulates.
The C8.3G will be introduced initially with two ratings, both of which deliver maximum power of 250 hp at the engine's rated speed of 2400 rpm. Peak torque will be 750 lb-ft @ 1400 rpm for one rating, and 660 lb-ft @ 1400 rpm for the second. Both are suitable for bus and on-highway applications. The engine is fully compatible with both compressed natural gas (CNG) and liquefied natural gas (LNG) fuel-delivery systems.
- Cummins Announces New C8.3G Natural Gas Engine, archive.org, retrieved on 2009-07-07