Steve and I packed a new 4Runner with all the necessary gear and loaded the Yamaha WR450F and 250F onto the trailer before leaving Dallas, while three buddies were making their way in from L.A. This would be our sixth excursion to our backwoods log cabin, deep in the Rocky Mountains of Clark, Colorado.

We headed due north and made a hard left turn at Salina, Kansas, onto I-70 westbound toward the mountains. This 4Runner Sport was equipped with the 4.7-liter i-Force V-8, five-speed ECT-i (Electronically Controlled Transmission with Intelligence), and full-time four-wheel drive. The two-speed transfer case includes a Torsen torque-sensing limited-slip center differential that can lock if necessary. The on-road ride and handling is a step up from the previous-generation 4Runner, and its high-speed stability is a strong asset when towing.

We were inspired to test the Toyota and Yamaha vehicles in unison because of the engineering link between the two. The X-REAS suspension system was developed by Yamaha. It comes standard on the Sport and is optional on the Limited 4Runner. Briefly, it diagonally links the shock absorbers and controls damping by means of a central control absorber.

Once on the road, we did find a slight driveline vibration transmitted up through the steering column at highway speeds beginning at about 1500 rpm under light acceleration. This was the same condition noted in the Lexus sibling GX 470. It was originally thought to be isolated to the GX, but now seems to be an issue in both 4WD SUVs. Toyota/Lexus engineers are in the process of diagnosing the problem.

The weather held up better than expected, and darkness set in as we reached the twisting mountain roads and gained elevation. As we'd seen in the Toyota Tundra a few years back, the 4.7-liter demonstrated minimal power loss in the thinning atmosphere as we climbed deeper into the mountains.