All hybrids are not created equal
Like it or not, electrically powered vehicles will soon be part of the product mix you’re selling… if they are not already. Increasingly restrictive fuel economy regulations mandated by the U.S. government and paralleled in Canada effectively force auto- makers to adopt some level of electrification.
But there is a wide range in both the way the manufacturers are electrifying their vehicles and how far they are going in that direction. As a result, the situation can be very confusing to consumers and sellers alike.
It means you not only have to know how your own products work but what competi- tors offer as well, so that you can discuss their relative merits with prospective customers.
‘Conventional’ hybrids
The most common current approach to electrification is hybrid technology, with which we are all familiar to some degree. It’s now more than a decade since the first- generation Honda Insight and Toyota Prius arrived in our market.
But all hybrids are not created equal. In fact, there are huge variations among the many vehicles that wear the hybrid label. Differences that were exemplified by those first two hybrids to reach our shores.
The Prius, along with all subsequent Toyota/Lexus vehicles using Toyota’s ‘Hybrid Synergy Drive’ technology, is what is called a ‘full hybrid’. That means that either its gasoline engine or its elec- tric motor(s), or both simultaneously, can directly drive its wheels (through an inter- mediary transmission, of course).
Ford’s hybrids use similar full-hybrid technology, as do Nissan’s, and most newer hybrids on the market are full hybrids, although details of their drivetrain configurations differ. The Two-Mode hybrid system shared by BMW, Daim- lerChrysler and General Motors, for example, achieved the same goal with an entirely different mechanical approach.
In contrast, the original Insight and most subsequent Honda hybrids employ mild hybrid technology. In a mild hybrid, the electric motor provides added power to assist the gasoline engine in driving the wheels, but it doesn’t drive the wheels by itself. GM’s first hybrid trucks were also mild hybrids.
Honda has subsequently revised the design of its Integrated Motor Assist system such that it can now be classified as full-hybrid technology.
One type is not necessarily better than the other. It’s a matter of balancing cost and com- plexity with the benefits achieved.
Micro-hybrids
A third approach is loosely classified as micro-hybrid technology. The current e-Assist system employed in the Buick LaCrosse qualifies as such, as did GM’s earlier passenger-car hybrids with “BAS” (Belt-Alternator-Starter) systems.
While they do provide some degree of electric assist to the engine’s power output, their primary value is in providing extra elec- trical energy to operate auxiliary systems, such as electric power steering, and to main- tain sufficient battery charge to employ an automatic start-stop system.
Automatic start-stop, which is common to all current hybrids, shuts off the engine when a vehicle comes to a full stop and automatically restarts it when either the brake is released or the accel- erator pedal is depressed. Because it eliminates fuel usage during idling, it is a major contributor to hybrids’ reduced fuel consumption in city driving.
While the fuel-economy gains provided are not huge, in terms of payback relative to cost, the micro-hybrid may be the most cost-effec- tive of all forms of hybridization.
“It’s now more than a decade since the first-generation Honda Insight and Toyota Prius arrived in our market.”
Plug-in hybrids
Not yet on the Canadian market but arriving soon, plug-in hybrids leverage the normal hybrid benefits by adding some initial level of battery charge, achieved by plugging the vehicle into the electricity grid. Typically, such systems can take from three to eight hours, using a normal 120V household outlet, to achieve full charge if the batteries are discharged.
That initial charge may be sufficient for the vehicle to operate for several kilometres on battery power alone, without engaging the engine. In some cases, in theory at least, commuters who travel only short distances would never have to use gasoline.
Ford and Toyota both have plug-in hybrids in their near-term production plans and several others are working on them.
Beyond these ‘conventional’ hybrids, there is a whole range of vehicles with only electric-drive, including the range-extended Chevrolet Volt, battery-electric vehicles (BEVs) like the Nissan Leaf, and fuel-cell electric vehicles like Honda’s Clarity. We’ll address them in this column in the next issue.
