After a lot of research, I replaced my Pirelli Scorpion Verdes with the NT421, despite the fact that there are very few reviews of the tire. But its treadwear rating and visual wear indicators were what sold me on it. They make it easy to monitor wear and know early in in the tires life if its wearing too fast. About 1300 miles in, I can say it is exceeding my expectations. While perhaps a little noisier than the the Pirellis on concrete roads, especially at highway speeds, I find it to be exceptionally quiet on blacktop. The dry grip is equal to the OEM Bridgestones and the Pirellis. As luck would have it, the first weekend I had the tires put on, I took a drive to visit family 2 hrs away, and a major winter-like storm blew in, with heavy rain, wind, and temperatures in the low 40s. The 421 performed better than the Pirellis did in wet conditions when I first got them. At highway speeds, it felt sure footed, particularly on the ramps. The extra shoulder support made a difference on curves and turns in these conditions, as did the deeper tread. The trade off for this extra grippy feeling is in the mpg. While my Q7 is no gas sipper, the Pirellis were low rolling resistance tires, and I was able to consistently get 20mpg at highway speeds on long hauls (moderate speeds, cruise control). So far the 421, which is not LRR, is giving me something closer to 17.5 or 18. These are still new enough where this may change. I also my inflate them to 38 or 39 psi to see if I get better mileage without noticeably sacrificing grip, ride quality, and noise. If these tires came in an LRR version, I would have paid a small premium for them. Please work on an LRR version of this tire. I know many SUV drivers use them like I do, as an everyday family workhorse, as opposed to constant towing or off roading. Many mix these uses. Saving on gas costs, however small, on a heavy SUV would be appreciated. I have no snow/ice conditions to report yet. Highly recommended. For the price, you can't get a better tire. And I am not sure that the minor price jump to the Pirellis gets you a better tires. Even the jump up to a Michelin seems large compared to the incremental differences in performance.
