In 2003, Ski-Doo literally reinvented the snowmobile with its revolutionary REV chassis. This innovative platform allowed BRP to jump well ahead of the competition in terms of ergonomics and overall riding dynamics. Last year, Ski-Doo engineers went back to the drawing board and designed an all-new architecture that's even more advanced than its predecessor. Called REV-XP, it's the product of five years of intense development.

The new REV-XP is both lighter and stiffer than its REV predecessor.

One of the main challenges facing engineers and designers was to create a new snowmobile with a much lighter yet stronger frame than the first-generation REV chassis. Working from the latter, they managed to develop a 23-kg lighter, 37-percent stiffer platform.

Creating a standard-size, liquid-cooled snowmobile under 182 kilos (400 pounds) had long been considered impossible. Yet, it's mission accomplished for BRP: for example, the new MX Z Trail 500SS only weighs 181 kilos (399 pounds).

A sizeable surprise
For 2009, BRP made a number of modifications and offers two new engines -- again with the goal of revolutionizing the snowmobile industry. Ski-Doo fans will be surprised to learn that the REV-XP chassis will be mated to an all-new, high-performance, 4-stroke powerplant. Contrary to what some people believe, Rotax (BRP's engine supplier) has actual experience with this type of engine. For several years now, 4-stroke Rotax units have been powering ATVs, Sea-Doos and turbine-equipped sport boats manufactured by BRP. The company also builds world-acclaimed 4-stroke engines for renowned brands, including BMW, Aprilia and Buell.

High-performance 4-stroke engine
This new engine has nothing to do with the V-1000 and V-800 that were initially designed for ATVs. It has what it takes to take on the best 4-stroke mills in the industry. In fact, as soon as you take off, you realize that it was specifically designed for a snowmobile.

The 3-cylinder engine boasts an exemplary powerband. On the flip side, vibrations are partly transferred to the handlebars and running boards. Granted, I was given a pre-production model; most likely, this problem will be addressed before the actual MX Z X is launched. Also, these vibrations fade away while engine speed increases.

The 1200 4-TEC engine might not be the most potent out there, but maximum power is available at lower RPMs. Meanwhile, the torque level from 7,500 to 8,500 RPM is higher than any competitor's.

The arrival of 4-stroke engines at Ski-Doo is more than welcomed.