#TireSize

TTAC Reader DeSoto writes:

Greetings, Sajeev — longtime reader, first time writer, and I enjoy the content your column adds to TTAC! (Woot! — SM)

I recently acquired an all-wheel drive 2014 Cadillac CTS with about 15,000 miles on its factory 255/35 R19 Pirelli P7 run-flat tires. Looking ahead to an upcoming 3,500 mile driving trip, I have concern for the durability/drivability of the run-flats. The CTS is not equipped with any wheel-changing tools (jack, wrench, spare tire/wheel). A spare tire assembly (for the CT6) is available online, but I believe the standard compact spare is too small in diameter to be compatible with the 19-inch wheels on the AWD drivetrain. I prefer the freedom of having the option of changing a tire myself and continuing on my way, rather than waiting hours for assistance. I am thus considering, in order of my current preference:

Curb Appeal? (photo courtesy: Greg)

Greg writes:

Hello Sajeev, David Holzman says I should write to you about my Mazda concerns.

1. Concern #1. In two out of three dealers there was significant rust at the center of the wheels due to the wheel caps not having been put on. I only took three pictures, but essentially: at New Country Mazda in Saratoga Springs NY 100% of the Mazdas had no wheelcaps on in the lot and were all showing various degrees of rust. That includes the one in the showroom, you can see it in the pic with the tile floor.

Gavin writes:

Dear Sajeev:

I have a Gen 7 Toyota Camry V6 and I am getting close to replacement of the factory 225/45/18 low profile tyres. The selection of long wearing low profile all season tyres in 45 series is pretty slim. The four cylinder version of my Camry has 215/55/17 tyres on 7×17 inch rims and the selection of long wearing 55 series touring tyres is much better. My question is, since I am not really a ‘sport driving type’, would it be better for me to find a nice set of wrecking yard alloys and downgrade to the smaller rim/taller sidewall size tyres? Is the difference in performance between 45 series and 55 series noticeable or should I stay with the original low profile tyres.

Finally, Discount Tire seems to really push their ‘tire certificates’, a road hazard protection plan for $20/tyre. Is Road Hazard really necessary on a vehicle equipped with TPMS?

Cheers,

Gavin