I've passed 25,000 miles on my TCH's Bridgestone Turanza EL400 tires. They all are wearing evenly and measure 7/32. My driving is about 80/20 mix of highway and city driving. I've been running the tires at 42/40 psi on the front/rear. I tend to drive the limit to 5 under and keep up with the slower traffic, when the freeway is moving. Most days I spend about 1/3 of my freeway drive in slow moving rush hour traffic.

Most likely I've got another 25K before I'll be replacing these tires. Maybe by then California will have published it's rolling resistance tire study results.

If anyone has replaced their tires and are getting as good or better mileage than the stock tires, chime in and let us know about it.

We unfortunately ended up with the Turanzas also. They won't make it to 25k, and we don't drive aggressively at all. The treadwear is only rated for 300 on these tires, so it's really no surprise, but I wish we had been blessed with the Michelins by the luck of the draw, as they at least have a 440 treadwear rating (not stellar either, but almost 50% better).