As the automotive industry moves toward electrification, battery costs and
vehicle range are two large issues that will delay this movement. These issues
can be partially resolved through the use of series-hybrid vehicles, which can
replace a portion of the batteries with a small engine that serves to recharge
the battery. Given the size, weight, and operational constraints of this engine,
a 2-stroke engine makes sense. Indeed, 2-stroke engines are currently being used
for a number of applications including consumer products, small ground vehicles,
boats, and drones. The technology has significantly improved to allow for
reduced emissions and increased efficiency, especially through the use of direct
injection. This article discusses the state of technology for 2-stroke engines
and its application in series-hybrid vehicles. In particular, the use of a
2-stroke engine as a range extender provides significant benefit in range and
cost over fully electric vehicles. The study found that although there have been
numerous gains in terms of efficiency and emissions, more advances are required
prior to the widespread usage of 2-stroke engines as range extenders.
