The Car Tech blog

(Credit: Mercedes-Benz)

Okay, so after a pair of supercar reveals on yesterday, let's take a step in a different direction and focus on something more environmentally friendly.

Hot on the heels of the S 400 Hybrid's European launch, Mercedes-Benz is set to trot our its new Vision S 500 Plug-in Hybrid at the 2009 Frankfurt auto show. (Wait, isn't BMW's new hybrid concept also called "Vision?" Oooh, scandalous!)

The Vision S 500's engine room is predictably similar to that of the S 400. Both vehicles use the same direct injected V-6 gasoline engine, both vehicles feature a electric ring motor sandwiched between the gasoline engine and the 7G-Tronic seven-speed automatic transmission. However, there are a few crucial differences.

Firstly, the S 500's 44 kW/60 horsepower electric motor is about three times more powerful than the S 400's 15 kW/20 horsepower unit. Additionally, the S 500's larger 10 kWh lithium ion battery pack is housed over the rear axle, instead of in the engine compartment.

A more robust electrical component allows the Vision S to go up to 18 miles on EV power.

(Credit: Mercedes-Benz)

Finally, the Vision S 500 Plug-in Hybrid is, as the name implies, a plug-in hybrid electric vehicle (PHEV), with its own onboard charger. Mercedes-Benz claims that a rapid charge cycle takes less than an hour with a 20 kW source. Recharging a completely discharged battery to full with a conventional household socket takes about 4.5 hours. Not too bad, we think.

Fully juiced, the Vision S can drive for up to 18 miles on silent electric power before the gasoline engine has to intervene. Mercedes is claiming a certified consumption of 73.5 US mpg (on the New European Driving Cycle), which pretty much blows the S 400 hybrid's 29 mpg out of the water.

(Credit: Mercedes-Benz)

Let's say you're a powerful dictator dignitary of a nation in turmoil. You obviously want to ride in style, and you probably won't be driving yourself around; but security is paramount, being a dictator dignitary and all, and you may occasionally find yourself the target of assassination attempts. So what's an iron-fisted ruler to drive? Well Mercedes-Benz may have the answer for you with the company's newly unveiled S600 Pullman Guard limousine.

The S600 Pullman Guard uses the same super-thick bulletproof glass as the G-Class Guard (pictured).

(Credit: Mercedes-Benz)

The S600 Pullman is the latest in Mercedes' 80-year tradition of armored vehicles and is essentially a stretched wheelbase version of the of the standard S600 sedan. The vehicle is able to protect passengers from military-standard small-arms projectiles and provides protection against fragments from hand grenades and other explosive charges. It does so by fully integrating armored panels into the body shell during the production process and reinforcing roof frame struts, door locks, door gaps, and exterior mirror mountings, while fitting some seriously thick bulletproof glass.

Making the S600 Pullman Guard as tough as a tank predictably results in a very tank-like weight. Mercedes compensates for this extra weight with an up-rated suspension and top-of-the-line 5.5-liter biturbo V-12 engine, outputting 517 hp with an impressive 612 pound-feet of torque. With run-flat tires, a self-sealing gas tank, and gobs of power on tap, you should have no problem getting out of all but the stickiest of situations.

VIPs will be sheltered from the bullets and pampered by luxurious materials and tech.

(Credit: Mercedes-Benz)

Mercedes-Benz also offers the standard wheelbase S-Class Guard, the E-Class Guard, and G-Class guard vehicles. Pricing isn't published. This, of course, means that if you have to ask, then you probably can't afford it.

After years of claiming that blue is the new green (in reference to its BlueTec diesel developments), Mercedes-Benz has taken a side step and introduced a hybrid to the market, the S 400 BlueHybrid. The modified S-Class sedan benefits from the addition of Mercedes' first hybrid drivetrain and the world's first implementation of a lithium ion battery in a production vehicle.

(Credit: Mercedes-Benz)

The lithium ion battery used is only slightly larger than a standard starter battery.

(Credit: Mercedes-Benz)

The battery, which makes this whole deal possible, is remarkable in that it's surprisingly compact thanks to lithium ion tech. The entire assembly is only slightly larger than a standard 12-volt car battery. The small size allows the battery to be located in the engine bay, where it replaces the conventional starter battery. This underhood placement, as opposed to a huge NiMH battery under the floor or in the center tunnel, means the S 400 BlueHybrid doesn't sacrifice interior or trunk space in the name of economy.

The modified V6 engine that powers the BlueHybrid has been "hybrid-ized" with the addition of a 20 horsepower disc shaped electric motor that is sandwiched between the gasoline powerplant and the 7G-Tronic automatic transmission, which produces 188 foot-pounds of torque. The electric motor boosts the output of the gasoline engine, but most of the efficiency gains are attributed to the way the electric motor works with the engine start-stop function. With the electric motor working as a starter, the engine can be shut off at speeds below 9 mph and instantly spun back up when it's time to go back onto gasoline power. Working together, the gas and electric powerplants generate 299 horsepower and 285 foot-pounds of torque and a pretty good combined fuel economy of 29 mpg. The S 400 BlueHybrid sits somewhere between the Lexus LS 600h L and the Toyota Prius on the gas-electric performance scale.

(Credit: Mercedes-Benz)

Inside the cabin, the S 400 BlueHybrid gets the requisite drivetrain monitoring displays that most hybrids seem to come with these days. Upon closer inspection, we see that the entire speedometer has been replaced by an LCD, while the rest of the gauges (tachometer, fuel, temp, and so on.) remain traditional.

Looking at the horsepower, torque, and fuel economy numbers again, it's fairly obvious that the primary goal of the hybrid system is to boost the performance and economy as opposed to push hybrid technology to new levels of efficiency. It's fairly obvious that Mercedes hasn't stopped believing in the merits of the diesel powered engine, because they've essentially recreated diesel performance with the hybrid drivetrain.