Europe’s heaviest combination vehicles can be found up north, especially in Finland. The country’s legal maximum GVM for a big rig is 76 metric tons (167,500 lbs). But that’s not all, domestic truck maker Sisu also offers the most powerful factory truck on the market, the 900 DIN-hp Polar Hybrid.
Sisu Auto builds on-/off-road trucks, heavy haulage tractors and other special vehicles. Don’t call them for a puddle jumper (to use Bryce’s term), as they only make jumbo-type of trucks, called the Polar-series.
The cabs, diesel engines and automatic transmissions are sourced from Mercedes-Benz. Manual transmissions come from Eaton-Fuller. The sturdy frames and axles are in-house products. Sisu has an excellent reputation for producing heavy-duty drive axles, both steering and non-steering. These are also used by other truck manufacturers, like Ginaf.
The extra powerful Polar Hybrid combines a 625 DIN-hp, 15.6 liter inline-six Mercedes-Benz engine (the mighty OM 473) with a 250 kW Danfoss Editron electric motor. A parallel hybrid system, with the electric motor placed between the diesel engine and the 18-speed Eaton-Fuller transmission. As mentioned, resulting in a grand total of 900 DIN-hp. The maximum torque output is a staggering 3,600 Nm (2,655 lbf-ft) @ 1,000 – 1,800 rpm.
Compared with a similar diesel-only Polar, the hybrid’s fuel consumption is claimed to be around 10% lower.
The hybrid system also has a manual mode -the blue switch on top of the gear lever knob- so the driver can control the extra grunt of the electric motor. The Benz diesel and the electric motor can be used simultaneously or separately.
The supercapacitors (for energy storage) are located behind the cab, neatly tucked away.
Another distinctive Sisu feature is a liftable, rearmost drive axle. That’s right, a liftable drive axle. Obviously, the single wheeled, steering pusher axle is also liftable.
Let’s have a closer look at the axles at the rear.
Giddy up go, two serious and seriously cool Finnish guys, spurring their hybrid Sisus.
Meanwhile, the Finnish trucking world and authorities aren’t sitting still. In January 2019, the national overall length limit went from 25.25 m (82’10”) to 34.50 m (113’2”)…
…and logging combinations with a GVM of 104 metric tons (229,000 lbs) are being tested (photo: Victor Asmoarp). Anyway, those northerners certainly got truckloads of horsepower! Or is it tons of kilowatts?
All Sisu Polar Hybrid images courtesy of Sisu Auto
A related, sort of, and interesting write-up: Sisu, the Finnish art of inner strength.