This paper determines the impact of ambient temperature on
energy consumption of a variety of vehicles in the laboratory.
Several conventional vehicles, several hybrid electric vehicles, a
plug-in hybrid electric vehicle and a battery electric vehicle were
tested for fuel and energy consumption under test cell conditions
of 20°F, 72°F and 95°F with 850 W/m₂ of emulated radiant solar
energy on the UDDS, HWFET and US06 drive cycles.
At 20°F, the energy consumption increase compared to 72°F ranges
from 2% to 100%. The largest increases in energy consumption occur
during a cold start, when the powertrain losses are highest, but
once the powertrains reach their operating temperatures, the energy
consumption increases are decreased. At 95°F, the energy
consumption increase ranges from 2% to 70%, and these increases are
due to the extra energy required to run the air-conditioning system
to maintain 72°F cabin temperatures. These increases in energy
consumption depend on the air-conditioning system type, powertrain
architecture, powertrain capabilities and drive patterns. The more
efficient the powertrain, the larger the impact of climate control
(heating or cooling) on the energy consumption.
A wealth of vehicle test data and analysis is used to explain
the nuances of the behaviors of the different powertrain
architectures at the different temperatures. Additionally, test
procedure details, charge-sustaining challenges, cold-start
penalties, cabin temperature pull-up and pull-down, idle fuel flow
rates, engine operations, impact of degree of hybridization, and
battery system resistances are discussed. The Appendix provides
time history graphs of all the data.