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Because of their light weight and small motors, they are extremely energy-efficient with a typical energy efficiency of 1.1 kWh (4.0 MJ) per 100 km [56] (1904 MPGe 810 km/L 0.124 L/100 km), even more efficient than bicycles and walking. However, as they must be recharged frequently, they are often collected overnight with motor vehicles ...
Using EPA 2018 Fuel Economy Guides assumptions for national average pricing of $2.56/gal regular gasoline and $0.13/kWh [42] we can calculate a vehicle that is rated at 84 MPGe or 40 kW/100 Mi efficiency and has a 16.5 kW EV battery of which 13.5 kWh is usable for electric driving with an advertised range of 33 miles per charge.
Example energy flows for a late-model (pre-2009) midsize passenger car: (a) urban driving; (b) highway driving. Source: U.S. Department of Energy [4] [5] Most of the fuel energy loss in cars occurs in the thermodynamic losses of the engine. Specifically, for driving at an average of 60 kilometres per hour (37 mph), approximately 33% of the ...
3) Efficiency was reported as "duty", meaning how many foot pounds (or newton-metres) of work lifting water were produced, but the mechanical pumping efficiency is not known. [15] The first piston steam engine, developed by Thomas Newcomen around 1710, was slightly over one half percent (0.5%) efficient. It operated with steam at near ...
The following table compares official EPA ratings for fuel economy (in miles per gallon gasoline equivalent, mpg-e or MPGe, for plug-in electric vehicles) for series production all-electric passenger vehicles rated by the EPA for model years 2015, [1] 2016, [2] 2017, [3] and 2023 [4] versus the model year 2016 vehicles that were rated the most efficient by the EPA with plug-in hybrid ...
To calculate the actual efficiency of an engine requires the energy density of the fuel being used. Different fuels have different energy densities defined by the fuel's heating value. The lower heating value (LHV) is used for internal-combustion-engine-efficiency calculations because the heat at temperatures below 150 °C (300 °F) cannot be ...
[9] [10] The energy efficiency is also occasionally known as energy intensity. [11] The inverse of the energy efficiency in transport is the energy consumption in transport. Energy efficiency in transport is often described in terms of fuel consumption, fuel consumption being the reciprocal of fuel economy. [10]
The power is equal to the drag force times velocity. For aircraft in cruise flight the lift is equal to the weight (L=mg) and the engine thrust is equal to the drag (T=D). Hence, ϵ = P / ( m g v ) = D / L = 1 / f {\displaystyle \epsilon =P/(mgv)=D/L=1/f} , with f=L/D the lift-to-drag ratio , so the specific resistance of airplanes is roughly ...