In spite of their past mistakes, I went over the my LTS and had new Toyos installed on the car. Except for a brief interlude of the OEM Turdenzas on the Emperor when it was new, the last three sets of Miata tires have been Toyo T1-S’s in 195/50 x 15. An excellent summer tire with tons of grip, wet and dry, fairly light weight and pretty affordable. The T1-S is no longer made and has been replaced by the T1-R.
With the new tire purchase I decided to try and kill a couple of birds with the one stone of a set of T1-R’s in 205/50 x 15. The 205 is the width of the tire in millimeters and the 50 is the sidewall height expressed as a percentage of the width, so this means that the tire should appear to fill the wheel well better with its .2 inch taller sidewall. Second, according to the Miata.net tire size calculator, my speedometer will now read 1.7% low. This is a good thing because the stock speedometer appears to be almost 7% high right now and a little compensation the other way will help make it more accurate.
The LTS was busy and they told me it might be an hour and a half before they would have my car done. No problem I told them, I brought a book. True to their word, it took almost exactly that long. When I handed them the keys I reminded them the torque spec for the lug-nuts was 75 ft/lbs and asked them to at least start the lug-nuts by hand before they impacted them on because last time they stripped one of my studs. To which the guy behind the counter replied, “When you do as many tires as we do you are bound to strip a few.” Jeez, nice attitude.
When I got home the first thing I did was check the torque and it seemed about right as I loosened them all, at least I didn’t need a breaker bar to get them off. I then re-torqued all 16 to 75 ft/lbs. Next up I checked the tire pressure. The door jab sticker says that Mazda recommends that they be inflated to 26 p.s.i. I’m guessing they inflated them by counting off so many seconds, one Mississippi, two Mississippi…because the pressure ranged from a low of 34 p.s.i. to a high of 42. I used to run 29 p.s.i. in the T1-S’s, but these are supposed to have a slightly stiffer sidewall so I took them all down to 26 and we see how they feel. While I was doing tire things, I decided, what the heck, to go ahead and clean the tire installer’s greasy hand prints off my wheels. I don’t even want to get into the whole leaving the thin foil tire label on the treads so that they would slowly flake off leaving a trail right to my driveway from the store.
Started down, went up, back down, still down.
Miata Top Transitions since 01/01/06: 194