The extended tread life test on CR’s Sienna AWD continues. And so far, so good. But let’s recap…
Toyota Sienna all-wheel-drive owners clearly have a beef with the short tread life of the standard run-flat tires and continue to share complaints in letters and Cars forums posts, especially in Tire Talk, the online-subscriber-only tire forum at ConsumerReports.org. We've also covered the frustration of Sienna owners regarding fast-wearing tires here in the Cars blog: "Toyota extends run-flat tire warranty" and "Toyota Sienna run-flat tires? Spare us."
As we’ve said before, most owners were pleased with the overall performance of their AWD Sienna--one of the top-rated models in Consumer Reports tests--but few are satisfied with the run-flat tire tread life, cost of replacement, and limited models from which to choose (two OE suppliers). Some even have psychological fears about not having a spare tire on board. To recap, many owners have complained that the run-flat tires wear out much quicker than expected or unevenly--often within 15,000 to 20,000 miles. Some owners found themselves facing an aggravating annual tire replacement, costing $700 or more. Toyota finally addressed the issue last year with an extended warranty on 2004 to some 2006 model-year vehicles, mostly addressing the irregular wear condition. Later-model vehicles came with a revised tire intended to eliminate the wear condition.
Our AWD Sienna
We purchased a new 2007 Toyota Sienna XLE AWD (ratings available to online subscribers) with the Dunlop SP Sport 4000 Self-Supporting Technology tires (DSST). After the road test was completed, we purchased a new set of Dunlop SP Sport 4000 DSST tires for a tread life evaluation on the Sienna AWD. The evaluation started at the end of March and at this point in July, we have a little more than 11,200 miles on the tires. We’ve been checking inflation pressures religiously, aligning the wheels, rotating the tires, and measuring the average tread depth in no less than16 test points around each tire every 2,000 miles. Now, most consumers are not likely to follow our frequent alignment and rotation schedule, but we’re giving the tires the best opportunity to wear optimally.
So what have we found up to now? In short, not much yet--the tires are less than 20 percent worn-out to the tread wear indicators, the wear is relatively even across the tread width, and we’re not observing any abnormal wear condition. At this early stage, the tires appear to be able to last more than 45,000 miles, even exceeding Toyota’s estimate of 40,000 miles noted in their Tire Information booklet. Still, we recognize that to get a more accurate picture of projected tread life, we’ll need more miles. We plan on doing just that with the hopes of reaching 20,000 or more miles by the end of summer. That shouldn’t be a problem, with many of our colleagues taking the minivan on extensive summer trips.
NOTE: An updated has been posted: "Update: Toyota Sienna AWD run-flat tires"
Related blog posts:
Update: Toyota Sienna AWD run-flat tires
Toyota Sienna AWD run-flat tires wear well for us
Toyota Sienna AWD tires - patience wearing thin
Toyota extends run-flat tire warranty
Toyota Sienna run-flat tires? Spare us.
Run-flat tires go flat with our readers