Nissan's first in-house-developed hybrid will be on sale in the spring of next year in the form of the 2012 Infiniti M35h. The Nissan Altima Hybrid, which is available only in a handful of states, borrows Toyota's Hybrid Synergy Drive technology. Being a brand focused on premium, sporty cars, you can be sure that the mooing we've become accustomed to from four-cylinder CVT hybrids will not be part of the M35h's package.
That package consists mainly of a 1.3-kWh lithium-ion battery pack, along with a powerful electric motor. At a technology seminar in Japan, Infiniti's engineers told us that the M35h's 360-volt motor is rated at 50kW (67 hp) at 2000 rpm and 199 lb-ft of torque. The system eschews a complicated CVT for a much simpler design where the AC motor is mounted in-line with the engine and 7-speed automatic transmission. A dry clutch takes the place of a torque converter and allows the gasoline engine to be completely decoupled from the driveline. A wet clutchpack at the back of the transmission performs two functions: firstly, it helps smooth out the powertrain by allowing some slippage during shifts and when the gas engine is being switched on and off. Secondly, by opening, it allows the engine to turn the motor/generator to charge the batteries with the vehicle stationary.
The gas engine itself is a VQ35DE running Atkinson cycle. (For those of you not geeky enough to memorize Nissan's engine codes, VQ stands for the familiar series of 60-degree V-6s; 35 denotes its 3.5-liter displacement. D = DOHC, and E = electronic control.) Note this engine isn't a 3.7-liter, nor is there a "HR" (high-revving) or "VHR" (very high revving) in the code. It also does not use VVEL infinitely variable valve lift. While the VQ35DE does have variable valve timing on all four camshafts, it's tuned for efficiency rather than maximum revs.
Still, it produces a very healthy 301 hp and 258 lb-ft of torque -- that's the highest output from this engine yet. Nissan isn't ready to quote a combined power rating , but you can imagine given both the potent gas engine and prodigious electric motor output, that the M35h is a fast car. And you'd be correct.
We had the opportunity for a quick drive in a prototype right-hand-drive Nissan Fuga Hybrid, which is the JDM (Japanese Domestic Market) version of the M35h on a closed course. It spent a lot of time on electric power -- even under mild acceleration -- and was very quick to turn off the gas engine. In fact, one Nissan engineer said that the electric motor alone is sufficient for cruising at speeds up to 60 mph, and that the car will switch off the gas engine completely while coasting at speeds up to 81 mph.
Over the one bump on the course, there was a bit of wallow from the rear suspension, making it very clear where the very heavy battery is located. Of course, this was a very early prototype, so that could (and likely) will change for production. The battery is, in fact, mounted in the trunk, and compromises cargo space considerably.
The M35h switches to electric power steering, and it does feel a little artificial. But again, this was a very brief drive of a very early prototype. The impressive part is how well the M35h preserved its sporty Infiniti driving experience. Acceleration is brutal -- the Hybrid felt equally as fast, if not faster, than a M37.
Infiniti says the weight penalty for the hybrid system is 265 lb, which sounds quite optimistic given the enormous battery. Perhaps that's over the V-8 M56? We'll find out when the final specifications are released. The engineers also pointed out that the system is 66 lb lighter than the hybrid system in the rival Lexus GS450h.
The other important set of specifications not yet finalized are the M Hybrid's fuel economy figures. Nissan says that the system brings the M's fuel economy to that of a 1.8-liter economy car. It just so happens that Nissan has one such car -- the Versa. And it's EPA rated at a combined 30 mpg. That's an enormous improvement over the M37's 21-mpg combined rating.
And we'll be surprised to see a rating that high. Still, we expect big gains over the nonhybrid M37, and we're looking forward to the final specifications, and a drive of the production version, later this year.