2011 Saleen S302
Software is tough stuff. Toyota now has 15 years of experience writing hybrid-electric control software, and it has no intention of sharing its hard-won expertise.
But blending changes in power flow among a combustion engine, one or more electric motors, regenerative brakes, and a high voltage battery pack in a way that's imperceptible-or at least tolerable-to drivers and passengers is a much tougher task than it may seem.
Which brings us to the 2011 BMW ActiveHybrid 7, the company's first mild hybrid and "the world's fastest hybrid vehicle." The first Toyota Prius back in 1997 wasn't a stellar vehicle and, frankly, neither is this one.
It's still a 7-Series BMW, of course, which means it's big, fast, solid, and luxurious. It may be the only hybrid in the world with electrically raised and lowered headrests, for example. And it's definitely fast when you put your foot into it, with a 0-to-60-mph time of just 4.7 seconds.
Like any BMW, the handling is exemplary. And it's a big car that's pleasant to drive fast, easy to place precisely on narrow roads, and predictable in its cornering behavior. We also liked the heads-up display; with crisp type in different colors, it's perhaps the best one we've seen so far.
But when the ActiveHybrid 7 is being a hybrid, it can be the least smooth of the many 7-Series models. Not at high speeds, when battery charging on engine overrun is all but imperceptible. Most of the time, you'd have to watch the power-flow display to see when the engine is charging the battery and when it's not.
It's the awkward low-speed behavior that trips up the ActiveHybrid 7. Below 25 miles per hour, lifting off in a normal car allows momentum to let it coast effortlessly until the driver brakes or accelerates.
But lifting off at those speeds in the hybrid 7 kicks on recharging instead--and the car starts to slow noticeably, as if it had driven into mud that was dragging it down.