Over the past month, I’ve sighted on average five to six Honda Insights in my daily travels in Klang Valley. The costlier “full hybrid” Toyota Prius is a less common sight than the motor assisted Honda, but they’re still more of them around compared to in 2010. This is of course the effect of Budget 2011, which abolished import and excise duty for hybrid cars below 2,000cc.
The hybrid car as we know it, is a more efficient and eco-friendly alternative to regular gasoline powered cars. With the assistance of a battery powered electric motor, cars like the Insight can get away with just a 1.3-litre engine. Fuel consumption and CO2 emissions drop as a result, not to mention that road tax is just RM70 per year in the Honda’s case.
Recently, we were lucky to be able to sample a different sort of hybrid, one that’s more about 700 Nm of torque than RM70 road tax. In the BMW ActiveHybrid 7, the batteries aid km/h, not km/l. Welcome to the performance enhancing hybrid car.
Continue reading the report after the jump.
The ActiveHybrid 7 made its world debut at the 2009 Frankfurt show. Designed to be “the most dynamic and luxurious rendition of the hybrid car”, it’s available in both short and long wheelbase formats of Munich’s S-Class rival. This is not a full hybrid where the electric motor can solely propel the car, but a mild hybrid without a dedicated EV mode.
The car’s main mover is a 4.4-litre V8 petrol engine featuring BMW TwinPower Turbo Technology and High Precision Injection, as used in the 750i. Despite already having power boost from the electric motor, BMW really went all out and has seen fit to tweak the V8 to produce 449 hp and 650 Nm of torque (from 2,000 to 4,500 rpm), which is quite a significant increase from the 750i’s 407 PS/600 Nm.
Now, throw in the output from the three-phase synchronous electric motor and you’ll get a total of 465 horses and 700 Nm of twist. Acceleration is staggeringly fast and effortless as a result – 0-100 km/h is completed in just 4.9 seconds and you don’t have to work hard to get it from there to the electronically limited 250 km/h top speed.
Taken bare, the figures aren’t out of the world, but put (or rather felt) in the context of a big, heavy limo, you won’t be asking for more pace.
On the other end of the scale, average fuel consumption in the EU cycle is just 9.4 litres/100 km or 10.6 km/l. The non hybrid 750i drinks 11.4 litres per 100 km, so there’s a big enough gap to justify the hardware. The CO2 rating takes a 47 g/km drop to 219 grams per kilometre. A gain on all fronts is hard to argue against.
The electric motor is positioned between the combustion engine and the transmission converter, and is connected firmly to the crankshaft. Shaped like a disc, it weighs just 23 kg. The battery that feeds it is the lithium-ion type, as opposed to Nickel Metal Hydride (Ni-MH) in Toyota/Lexus hybrids.
Comprising 35 cells and weighing 27 kg, the 37 x 22 x 23 cm battery unit (quite similar in size to a normal car battery) is located in the boot next to the left wheelarch. It takes up about the same space as the additional compressor for the rear-seat air con in the standard Seven, which is not present here.
From the driver’s seat, there’s nothing to tell that you’re not in a regular Seven, until the black panel instrument cluster lights up to give some clues. At the fuel consumption gauge, there’s the word ‘ActiveHybrid’ in light blue, along with the ‘READY’ sign next to the gear selection. Heed the call and press the Start button and instead of a loud V8 rumble, it’s so silent that you wonder it’s alive. This is a hybrid all right.
We carefully inch out of the incredibly tight parking lot of Munich’s Sofitel, trying hard to not to kerb the ActiveHybrid’s unique aerodynamically optimised turbine style 19-inch alloys. In the motherland of superminis, our Seven feels every bit the limo it is. We ease our way into Munich’s morning traffic while taking the first ten minutes to reacquaint ourselves to left hand drive. Wafting around town, we could hear more of the other vehicles than our own powertrain – the AH7 cabin is very well insulated indeed.
At low speeds, the electric motor does part of the work so as to not trouble the V8 too much, helping fuel economy. The big engine, mounted as far from the nose as possible in typical BMW fashion, was rudely awakened when we had the first opportunity to floor the gas pedal. It responded angrily to the poke, and yours truly was left speechless as the AH7 took a squat before propelling itself down the road. It felt much shorter than five seconds to reach 100 km/h, probably because the response seemed so improbable moments ago.
Speed isn’t fun without noise, and thankfully the good insulation we noticed in the city wasn’t so good to block out all of the engine noise, which is a deep, bassy growl in this case. From this moment on, we gave it full beans at every opportunity just to be punched by the speed/noise combo, even if it attracted disapproving stares from the locals. One lady cyclist gave a particularly nasty look. No class, they must be thinking.
Getting out of the city and into the country got me thinking the same. This is no S-Class. This fifth-gen Seven is a great car to drive for what it is, and we applaud BMW for making it like that despite the fact that most of these limos will never breach 70% of their cornering ability as to not alarm the boss. By the way, the AH7 manages to stick to the 50:50 weight distribution Munich is obsessed with, despite the added hardware.
Pushing hard still feels unnatural due to the car’s width (amplified on narrow Euro country roads) and the visual of that long hood from behind the wheel. There were some close shaves with oncoming trucks, and I was relieved to return the car later without any dangling side mirrors. While it’s more suited for Sheikh Zayed Road than Bavarian country road, look past those and you’ll be rewarded.
“Shrinks around you” may sound a little cliched, but it applies to the ActiveHybrid 7. Like the rest of the Seven range, it’s very nice to drive and doesn’t feel as clumsy as its bulk suggests, the only deterrents being the above-mentioned width and view of the long hood.
Push on and you’ll find tight body control and a planted feel in Sport mode, although we couldn’t find any bad roads to test ride comfort. The difference between Sport and the softer, lazier Comfort is apparent, the former holds revs for longer instead of upshifting at every opportunity.
Back when BMW first launched its eight-speed auto gearbox, I questioned the need for so many ratios – wouldn’t a well chosen six-pack be enough? But it works well and the feared gear hunting is not present, so all’s well. By the way, there’s auto start-stop as well, so you don’t burn fuel for nothing when idle.
After establishing that the AH7 isn’t a fish out of water clipping apexes on country roads, we went on to fiddle around with its green gadgets via iDrive, which in present form, is no longer as cumbersome to use as the original version that debuted in the previous generation E65/E66 7-Series.
The large central screen can display a live graphic that shows the energy flow, whether it’s support from the electric motor when accelerating away, or from brake regeneration into the batteries. The current charge level of the batteries is also displayed. If you’ve been really good, give yourself a pat on the back as you analyse the current level of efficiency in per cent. A bar diagram updates itself every minute, showing to what extent the efficiency potential of the hybrid components have been exhausted in the last 15 minutes.
That’s all cool in a geeky way, but I reckon that maximising fuel savings and minimising dirty emissions isn’t what the ActiveHybrid 7 is all about. This hybrid is about performance, performance and performance, and the improved economy and CO2 ratings are just convenient subsidiary benefits to help justify adding more horsepower to a two-tonne car in today’s climate. Cheeky!