Below is the information for the tires that are provided with the optional Sports Package and Track Handling Package on this car (BMW 435 Coupe) that give the car the grip to accelerate, decelerate, and its cornering capability: 255/35 R19 92Y Pirelli P Zero run flats 3515 for the rear and 225/40 R19 89Y Pirelli P Zero run flats 3515 for the front tires. 255 is the width of the rear tire in millimeters, 35 is the height of the sidewall as a percentage of the width of the tire, R means radial construction, 19 is the diameter of the light alloy rims (19 x 8.5 inches rear rims, 19 x 8.0 inches front rims), 92 is the load bearing capacity of the tire, Y is the speed rating of the tire, i.e 186 mph ( 300 kmh). Run flats means there is no spare and if I have a puncture in theory one can drive up to 100 miles at speeds not to exceed 50 mph. The speed rating of a tire should always exceed the top speed capability of the car they are used on. 3515 is the manufacturing date of the tire (35th week of 2015). Also on a tire but not shown here is the tread wear rating, temperature rating, and water dissipation capability of the tire tread. The emphasis on high speed tires is performance, not tire longevity. Other factors are as important in performance as the tires. i.e. the suspension, on this car the suspension components are primarily made from aluminum, also anti-roll bars front and rear, and a cross bar inside the engine bay to prevent flexing during hard cornering, and last but not least, center of gravity, the lower the better. The manufacturing date is very important. Tires degrade over time, even when not driven. With air temperatures exceeding 100 F for four months of the year here in the Southwest, highway surface temperatures may reach 190 F and tires could blow,. This picture was taken on 11 September 2016, Sig... PS: My car is due the one year inspection and I was getting static from my friends for not washing it. So I decided to wash it early on September 11, before sun up before it got too hot, and then I decided to look under the hood, wiped off the dust and then I decided to take some pictures and document what I had, and then I decided to post some of the pictures since I didn't have anything else to post.