If you've chosen category 1 or 3, your taxes are calculated at the Single rate. Category 2 is calculated at the Married rate. Here is how the marital status categories appear in the Tax Data section of your pay statement: What You Claim on Your W-4.
Remember, with winter tires only the first 50% of tread is really for use. After that, you have the equivalent of half-worn all-season tires. Blizzak special outer rubber differs from lower layer, too, as the maker informs. Winter tires with 11/32 new tread depth are effectively kaput at 6 or 5 / 32. You should not push regular tires below 4/32 in any case, see wet stopping distances at full, at 4 and at 2 /32 video comparisons on Tirerack.com.
Tread depth is a vertical measurement between the top of the tread rubber to the bottom of the tire's deepest grooves. In the United States, tread depth is measured in 32nds of an inch. Because it is difficult to accurately measure tread depth with a ruler, tread depth is best measured with a tire tread depth gauge.