Christmas tree cultivation major Christmas tree growing region, Douglas-fir has always been the primary species grown. A full one-half of all trees produced in the Pacific Northwest are Douglas-fir. Douglas-firs typically take five to seven years before they are mature enough to sell as Christmas trees. Also common in the region are noble fir, a tree which commands a higher price than Douglas-fir, and grand fir, which accounts for about 10 percent of the annual harvest in the Northwest. Other species collectively account for only 3–5 percent of the total Northwest harvest. In North America, Fraser fir, grown in the Appalachian Mountains of
Noble M15 the M400. Mounting the engine longitudinally (rather than transversely as on the M400) allowed the engine designers to increase the cooling flow to the engine, which allows the twin-turbo Ford Duratec V6 engine to develop . The engine has been designed to meet European emission standards and the new steel/aluminium space frame has been designed with a view to passing crash test regulations around the world. The M15 is planned to be the first Noble which gains European and US type approval. Like all the Noble M models, the M15 has a steel spaceframe and roll cage covered with graphite-reinforced