By Bertie Scott Brown, September 9, 2014
Though internal combustion engines still dominate today’s motive power on our highways, electrification is emerging rapidly. The objective is to eliminate huge engines with poor fuel economy.
Instead tomorrow’s vehicles will likely rely on fuel cells where hydrogen reacts with oxygen, producing nothing more than energy and water, or electric motors.
Mind you, the battery-powered electric vehicle has existed almost as long as the car itself and though their sales still represent a tiny proportion of total car sales, battery-powered electric cars are becoming an increasingly strong force. No cylinder blocks or heads, pistons or connecting rods, crankshafts or camshafts. Even exhaust systems vanish and all replaced by an electric motor.
Plug-in hybrids usually refer to vehicles with engines supplemented by rechargeable batteries or other storage devices like flywheels that can be restored to full charge by connecting a plug to an electric power source. Current US wireless technology probably already supersedes the plug-in model, operating by simply driving the vehicle over a wireless charging pad.
But earlier this year Porsche’s innovative 918 mid-engine sports car arrived in the US. A plug-in hybrid, its 4.6 liter V8 engine, which weighs 298lbs, develops 600hp at 8,500rpm and 390ft-lbs torque with two electric motors delivering an additional 280hp, giving a combined output of 880hp (600kW). The energy storage system is a 312-cell, liquid-cooled 6.8 kWh lithium-ion battery pack positioned behind the passenger compartment.
The jolt from its battery power sends this hybrid from 0-60 in 2.5seconds. More importantly it has the ability to fully recharge its battery pack while driving via the car’s regenerative braking system and also while the engine is coasting. Clearly future performance will be determined by the efficiency of quick-charging batteries rather than the power of the internal combustion engine.
But the pure electric car rather than a plug-in hybrid has also made stunning progress in the form of the Tesla S P85—a car that covers 250 miles on a charge. It’s available with three outputs which equate to 300hp, 360hp and 420hp giving claimed 0-60mph acceleration times from 5.9sec to 4.2sec, and top speeds from 120–130mph. Maximum torque generated by its most powerful three-phase AC induction motor is stated as 440ft-lbs.
Charging times for the Tesla’s lithium-ion battery pack range from 15 hours at a public station to about 7.5 hours by Tesla’s home charging kit.
Imagine for a moment the devastation of our aftermarket if the transition happened overnight! Still, ours is the hothouse of ingenuity and no doubt our industry would soon discover how to make it better.
“Everything in life is somewhere else and you’ve got to get there by motorcar.” –E.B. White