"When U.S. Environmental Protection Agency regulations for snowmobiles started in 2006, Ski-Doo already had its 600 H.O. SDI two-stroke engine on the snow for two years. It was considerably cleaner than regulations required and it achieved industry-leading fuel economy. The engine was light, powerful, dependable and clean.
As the Bombardier Recreational Products (BRP) Evinrude group developed the E-TEC system for its outboard motors (BRP acquired Evinrude in 2001), it became clear that this technology could translate directly to Ski-Doo snowmobiles. In the winter of 2008, Ski-Doo released the 600 H.O. E-TEC engine.
Is the E-TEC engine a big deal in the world of snowmobiling? Absolutely. It demonstrates that the two-stroke engine — with all of the advantages it offers for snowmobiling — is far from being axed from snowmobile manufacturers’ product plans. The 600 H.O. E-TEC is available across Ski-Doo’s 2009 lineup and further expansion of the direct injected technologies will prove the strength of the two-stroke engine design and its attributes."