Michelin PLR (Poids Lourd Rapide – loosely translated as "fast truck")
Based on the estate version of the Citroën DS, the PLR was a 10-wheeled tyre evaluation test platform built in 1972 by Michelin, at a time when the company was a shareholder in Citroën. At 8 feet wide and 24 feet long, and weighing up to 9.5 metric tonnes (just under 21,000 pounds) with additional lead weights, the PLR could reach a speed of 110mph/180kmh. Nicknamed "milles-pattes" (French for centipede), it was conceived as a way to test out truck tyres at high speed without taking the the risk of using an actual truck. The general idea was that if there was a blow out, the engineers didn’t have to worry about losing control of their vehicle.
Although it housed two Chevrolet 454 Big-Block V8 engines in the tail section, only one was used for driving the six rear wheels. The second was used to drive the sample tyre being tested in the middle of the PLR which, via the use of hydraulics, could be raised or lowered and aligned in various positions on the tarmac to put it through its paces.
The PLR spent its life doing laps of Michelin's Ladoux test track in Clermont-Ferrand, and after being phased out in favour of more sophisticated tyre testing machinery later on, now spends most of its time within the company's museum in the same city, occasionally making appearances worldwide as a promotional piece at fairs and exhibitions.