The Polar Challenge is an actual ski established in 2004 and taking place mid-April and mid-May each year, taking teams approximately 4 weeks to complete, including the training time. I am not sure how closely top gear followed the route, but here it is(the starting and finish locations are the same):
The route
The average yearly temperature at the starting point, Resolute, Nunavut, Canada is −16.4 °C (2.5 °F). The temperatures at the final point of the journey may reach as far as -52°C in winter.
The whole journey took Clarkson and May from 25th of April till 2nd of May.
The Car
3 Liter Diesel 4 cylinder inline engine.
175 KMPH Maximum Speed
0-100 in 11.9 seconds
25MPG
The truck starts at 17899 US dollars for the basic model, the top-end model listed here starts at over 59 grand. Hilux is sold in Europe, Asia and Oceania, it is substituted by Toyota Tacoma in the North American market. It is however, not just a simple name change- Tacoma is a very different car under the bonnet. I'm sure it is just as durable however.
Special modifications for the race:
# The standard wheels and tyres were replaced with bespoke Arctic Trucks wheels and 38" studded snow tyres. The tyres were able to run at pressures as low as 3psi for better flotation over snow. The tyres are called Arctic Trucks AT405.
# The wheel arches were raised and extended to protect the larger tyres
# The standard 3.0-litre D-4D engine was modified to cope with the very low temperatures. Heaters were added to increase fuel and coolant temperature, a large heavy-duty battery was fitted and the air intake was modified.
# A 90 litre auxiliary fuel tank was fitted
# The gearing ratio was lowered to 4.88
Why? Reducing gear ratio allows car to maintain slower speed, and increases torque- force basically sent to drivetrain, both vital factors to overcome offroad conditions.
# Two Winches that could be fitted either to the front or rear of each of the vehicles were carried, in case they got stuck in the snow
Work began on the vehicles in December 2006, at Resolute, Canada, from where the expedition would begin. Over 240 man-hours of labour was spent completely refitting the two vehicles in preparation for the journey. Testing of the vehicles began in February 2007, after which some further modifications were made to the vehicles — the suspension was altered and the original 29" tyres were replaced with 38" ones
Why they chose Toyota Hilux:
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The opposition
Opposite the car was Richard Hammond and Matty McNair, on a dogsled.
Who's Matty McNair?
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A wiki excerpt.
Matty L McNair (b. ) was born in Pennsylvania, USA but now lives in the Canadian Arctic in Iqaluit, on south Baffin Island, where she runs her company NorthWinds. Among her many accomplishments are:
* 1997 leading the first ever all-female expedition to the Geographic North Pole.
* 2000 she led an expedition across Ellesmere Island through the Sverdrup Pass.
* 2003/04 she led two ski-all-the-way expeditions to the South Pole.
* 2003 crossed the Greenland Ice Cap with her children Sarah and Eric by ski-kites with dog sled support.
* 2004/2005 completed an unsupported ski expedition to the South Pole, again accompanied by her children Sarah and Eric, who became the youngest persons to ski to the South Pole.
* 2007 drove a dogsled with Richard Hammond to the Magnetic north pole as part of Top Gear: Polar Special
* She is the first Canadian to ski to both the North and South Poles.
How fast are the dogs? Well, again, wiki describes it rather perfectly:
Racing sled dogs will travel up to an average twenty miles per hour (32.2 km/h) over distances up to 25 miles (40 km). Over longer distances, average traveling speed declines to 10 to 14 miles per hour (16 to 22 km/h). In poor trail conditions, sleddogs can still usually average 6 or 7 miles per hour (10 or 11 km/h). Sled dogs have been known to travel over 90 miles in a 24 hour period while pulling 85 pounds each.
Finally, the race itself!(click me, a youtube playlist)
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Richard Hammond never made it to the pole, as it "seemed cruel to make him go the extra distance just so Clarkson could gloat".
Enjoy!