flycaster

Recently had the 2016 C300 coupe (with only 10,000 miles) in for some minor repair. Repair was done, but MB showed me that my right front tire was wearing unevenly on the outside tread. They said that I needed a wheel alignment. Wasn't going to give them $350 and took the car to a trusty Firestone for a front end alignment. Got a call from the Firestone tech who was doing the alignment telling me that there was nothing wrong with the right front end (Normal range=0.07-0.24, actual Toe=0.19 "corrected" to 0.16), but that the left front end's Toe was out (Normal range= 0.07-0.24, actual Toe=0.32 corrected to 0.18). Furthermore, for the front end, Cross Camber and Cross Caster were also well within normal ranges, and Total Toe before alignment was 0.50 corrected to 0.34 (Normal range=0.15-.049). The left and right rear tires were all well within normal Camber/Toe ranges. BTW, I always check tire pressure and keep my tires at 35psi all around, and I do not gas-*** the car.

So, here I am with the quandary as to why the right front tire, whose alignment was within normal ranges, should be wearing down to replacement level. I called my SA to discuss this with him. He kept saying that Firestone knows nothing about aligning these cars (know nothing about the specs for alignment) and offered the following: Bring the car in, put it up on the alignment rack and if alignment was OK, no charge. However, if out of alignment, then a charge. Well, before doing that, I asked him for a Mercedes Benz printout of the expected normal range for alignment specs for my car. The purpose of this request was to see if Firestone was looking at the same specs as MB uses. Well, to say the least, he was adamant that each car had different specs and there was no protocol wheel alignment specs that he could get to me. This has to be BS as I can't believe that there is no print out as to what a specific models alignment specs should be??? While I'm awaiting to here from the service manager, I certainly wouldn't mind some in put from you guys: (1) Why would tire wear so unevenly even though correct tire pressure is always maintained and all alignment parameters are well within normal specs? (2) Shouldn't MB documentation for normal alignment specs for the C-300 be available???

PS: Car's lease is up in August. If I were or needed to get a new tire, do I have to replace with the same exact tire, or can I get a similarly rated tire?

Thanks.