Thanks to Scott for informing me of my FACTORY warranty on my Yokohama tires, I was able to get new ones at a pro-rated price.
I purchased a set of Yokohama Avid H4's about 9 months and 23,000 miles ago. Well they still had some tread left (except the driver's side rear tire which had the cord showing through on the inside of the wheel!?), but were at the tread wear indicators. So I was pro-rated on 3 of the tires and the 4th one (left rear with uneven wear) I had to buy new. The salesman @ the certified Yokohama dealer told me that the Avid H4's were replaced by the YK420, same class tire basically. And the new ones even had a 60k warranty! Plus I would get roadhazard warranty, and free rotation and balancing for life of the tire. And all of it for only $280. Sounds like a good deal to me! Well I went over there today and had all of this done. But upon inspecting the new tires, I noticed they sure had A LOT of tread on them. I thought, wow, that is good! But I left there and the tires handled WORSE than my old and mostly thrashed tires! Upon cornering, it felt like the extra tread just seemed to bend, and it didn't feel "right." I was later on driving with my friend Bianca, who said to me that the tires just needed to be 'worn in' to perform properly. I was like... WHA!? A girl nows something I don't!? (I always tell her a famous line from a movie [can you guess which movie?], "Women and machinery don't mix!")

My questions, do new tires really need to be worn in? And if so, how long is the break in process?

2. Is the YK420 in the same class as the Avid H4s? I will call Yokohama to find out for sure if no one knows.

3. Does the extra tread on the tire 'bend' under pressure, and does this make for worse handling? If so, should I try and get different tires, ones that performed like the old ones?

Thanks a bunch guys!! :p

__________________
2006 E350 w/ 155k miles (Daily Driver)

Previous:
1993 300E 3.2L Sedan w/ close to about 300k miles
2003 E500 Brilliant Silver (Had 217k miles when totalled!)
1989 300E with 289,000 miles (had for <1 yr while in HI)
03 CLK 500 cabrio (Mom's)
2006 C230k (Dad's)
1999 S420 (Mom's/Dad's)
2000 C230k Sport sedans
2001 CLK320 Cabrio (Mom's)
1995 C280 My First Mercedes-Benz... (155k miles. EXCEPTIONAL AUTOMOBILE. Was Very hard to let go of!)

..always better to do homework and tire comparisons prior to purchasing:

ie how the tire is put together, tread design, compound composition, load capacities, sidewall construction etc.

in general, the longer mileage wearing tires will provide a lesser degree of performance vs. the shorter mileage wearing ones (for obvious reasons)

also in general, the worn set that you just took off- more closely resembles a racing slick/ competition tire (no or little tread) and so you'll feel better performance from the old set- in the dry (all else being equal- & barring any structural breach)

....if the YK 420 is not a performance oriented tire- it may be performing flawlessly according to its design/ target

let us know what turns out
-fad

Well David, your (girl) friend is right. Tires need to be driven for at least a couple hundred miles before they perform. This is kind of heat cycling that racer do (and the Rack offers to do the same in an oven) to their tires before they race them. Basically it is just cross linking of the rubber to make them harder therefore less squirm. Also, taller the tread means more bending, less traction in the dry.

Have you check the tire pressure? Typically more is better. Don't go over the max allowed listed on the sidewall of your tires. Good luck.

Tommy

Well about 400 miles later, and an increase in tire pressure (32 up front, 35 in the rear), I am beginning to enjoy the feel of the 'squirming tread' when cornering. I can't place what it is... but now that I have a feel for them, and they're worn in a bit, I like the feel. They do corner much better than when I drove off the lot. Now I just need to have my lower control arm bushings fixed.........!!!!!!!!!!!!!!!!!!!!!

__________________
2006 E350 w/ 155k miles (Daily Driver)

Previous:
1993 300E 3.2L Sedan w/ close to about 300k miles
2003 E500 Brilliant Silver (Had 217k miles when totalled!)
1989 300E with 289,000 miles (had for <1 yr while in HI)
03 CLK 500 cabrio (Mom's)
2006 C230k (Dad's)
1999 S420 (Mom's/Dad's)
2000 C230k Sport sedans
2001 CLK320 Cabrio (Mom's)
1995 C280 My First Mercedes-Benz... (155k miles. EXCEPTIONAL AUTOMOBILE. Was Very hard to let go of!)

yeah- David-

once you get the worn suspension addressed- it'll feel as new again

-fad