'Mean Green' is a unique hybrid truck built by an enthusiastic team at Volvo Trucks. They plan to use it next spring to beat the world speed record for the standing kilometer, with Swedish truck racing ace, Boije Ovebrink behind the wheel.
"The experts in Volvo's hybrid technology are the driving force behind the project. They are true enthusiasts, every last one of them. I'd go so far as to s ay 'Mean Green' is the world's fastest hybrid truck," said Ovebrink.
To understand how he can make this claim with such confidence, we need to rewind to November 2007. Ovebrink had just beaten his own standing kilometer record from 2001 for trucks with a maximum displacement of 16-liters. He achieved this by reaching an average speed of 158.829km/h (98.7mph) with his red Volvo NH16 (aka. 'The Wild Viking').
After winning, he met Staffan Jufors, President and CEO of Volvo Trucks and Ovebrink explained he'd like to build the world's fastest hybrid truck.
Planning for the hybrid got under way, but in the meantime, a Czech truck team claimed they had beaten Ovebrink's record. So Volvo engineer Olof Johansson got down to some serious work. He started building a truck that could retake the record, but that could also be reconfigured for the planned racing hybrid driveline. That truck is now called 'Mean Green'. But the team decided not to install the hybrid driveline straight away.
"I started building the truck from two half frames that had been earmarked for the scrapyard, and the American VN cab came from a crash-tested chassis whose cab was totally intact," he explained.
Weight reduction was absolutely crucial to setting new records. For example, the front axle was milled by Volvo's engine factory in Skovde, Sweden and reduced from 100kg to 57kg (126 lb). Then the gear set for first gear was removed from the gearbox, shaving another 7kg.
"I slit open the wiring harnesses and removed unnecessary wiring. That slashed almost 6 kilos," said Johansson.
Ovebrink was also ordered to lose weight, as he recalls, "They made me promise to lose 20kg and, so far I'm half-way to my target."
Volvo Designer Jonas Sandstrom put in many hours with his CAD program to come up with the optimal aerodynamic shape. "It's important the wind breaks away from the bodywork in the right way. Our truck differs from a Formula 1 car in that the aerodynamic properties allow the truck to slice through the air rather than be pressed down onto the road surface," he explained.
Just a few days before the assault on the record, it was announced that FIA had disallowed the Czech team's resul but there was no need to cancel the attempt on the record.
Ovebrink and the Volvo team were aiming to further improve on the 2007 record - and on June 9th 2010 they did just that. The new world record for the standing kilometer was set at a two-way average speed of 166.7 km/h (103.6mph). Top speed was in the region of 260km/h (161mph).
Once this was achieved, focus reverted to what the project had been about from the very outset. "Olof immediately went on the offensive. The very same day the record was set, he pulled out his toolbox and started modifying the truck to build what we see today - a thoroughbred hybrid."
The truck already had a standard Volvo 16-liter 700hp Volvo Penta engine. With twin turbos it delivered a massive 1900hp. The lightened Powertronic auto-shifter was replaced with a modified version of Volvo's automated I-Shift gearbox so the transmission could interact with the component that makes 'Mean Green' a hybrid - its electric motor.
"This gives an additional 200hp and 1100 Nm (811 lb-ft) of torque. The result is a speed boost from start without any of the customary diesel engine-lag. For the first couple of seconds, the truck makes a slight whistle until the diesel engine, which runs on renewable liquid rosin diesel, starts delivering with explosive force - by which time the truck is already doing 60km/h and I can engage ninth gear," explains Ovebrink.