That's the bad news. The good news is the car can be ordered with a spare tire, all are coming that way now. So there is no reason to switch to a good, conventional tire.
On the sport I saw the tires were 245/40-19 Dunlop SP Sport 5000M DSST CTT, listed by Tire Rack as an Ultra High Performance All-Season: http://www.tirerack.com/tires/tires.jsp?tireMake=Dunlop&tireModel=SP+Sport+5000M+DSST+CTT Tire Rack only has 15 customer reviews dating back to 2009. Few tires are rated lower by the owners.
On the two standard models the tires were Bridgestone RE97 A/S RFTs. This most be brand new. The RE97 appears to be a new tire for 2013 with the few Tire Rack reviews being from Cadillac XTS owners. They don't like it.
Right now, if you must go runflat, your best choice is probably the Bridgestone RE960 A/S Pole Position RFT. Introduced in 2011, it is an RFT model of a tire introduced in 2007 whose replacement, the RE970 AS Pole Position, was introduced in 2011.
However, if you have the spare, I recommend adding a inflation kit with sealant to the trunk (about $40), getting the spare, and changing the tires. For most, the new for 2013 Michelin Pilot Sport AS3 is probably best. Latest technology all-season, it has a 500 wear rating.
If performance is your goal, the Michelin Pilot Super Sport has been the premier high performance tire for 2-years. Two 2013 attempts to knock it off its perch were unsuccessful. It is not the first choice for track days or serious autocross competition, but should be the best high performance street tire you can get. Wear rating 300.
If you find the Michelins a bit pricy—they are about 50% more than most of their competition—there are Bridgestone and Continental models that are quite good. Just not as good. Including the RE970 A/S (wear rating 400) mentioned previously. For example, the RE970s are $912 at TireRack, the PS AS3s are $1076. The PSSs are $1092. The RE-11 is $920 and the S-04 Pole Position is $804.
The choice is much sparser for the non-Sport model. The standard 225/55-17 is an odd size. Michelin does list he PS AS3 in that size and Conti has the ExtremeContact DWS. The 7.5" rim can also fit a 245/50-17, but that is also an odd size. The Conti DWS is available in that size though.
Michelin info on their tires: Shop for Ultra-High Performance Sport Tires | Michelin Tires
Conti UK video on inflation kit:
This is the less expensive Slime kit with the same functionality:
Even if you stick with the runflats, I recommend carrying the inflation kit with sealant. Running on the zero pressure runflat makes the tire unrepairable and frequently damages the rim at the same time. This is a big topic on the BMW forums that have used the same 19" size tire for years. The replacement for the runflats are very expensive.
On the sport I saw the tires were 245/40-19 Dunlop SP Sport 5000M DSST CTT, listed by Tire Rack as an Ultra High Performance All-Season: http://www.tirerack.com/tires/tires.jsp?tireMake=Dunlop&tireModel=SP+Sport+5000M+DSST+CTT Tire Rack only has 15 customer reviews dating back to 2009. Few tires are rated lower by the owners.
On the two standard models the tires were Bridgestone RE97 A/S RFTs. This most be brand new. The RE97 appears to be a new tire for 2013 with the few Tire Rack reviews being from Cadillac XTS owners. They don't like it.
Right now, if you must go runflat, your best choice is probably the Bridgestone RE960 A/S Pole Position RFT. Introduced in 2011, it is an RFT model of a tire introduced in 2007 whose replacement, the RE970 AS Pole Position, was introduced in 2011.
However, if you have the spare, I recommend adding a inflation kit with sealant to the trunk (about $40), getting the spare, and changing the tires. For most, the new for 2013 Michelin Pilot Sport AS3 is probably best. Latest technology all-season, it has a 500 wear rating.
If performance is your goal, the Michelin Pilot Super Sport has been the premier high performance tire for 2-years. Two 2013 attempts to knock it off its perch were unsuccessful. It is not the first choice for track days or serious autocross competition, but should be the best high performance street tire you can get. Wear rating 300.
If you find the Michelins a bit pricy—they are about 50% more than most of their competition—there are Bridgestone and Continental models that are quite good. Just not as good. Including the RE970 A/S (wear rating 400) mentioned previously. For example, the RE970s are $912 at TireRack, the PS AS3s are $1076. The PSSs are $1092. The RE-11 is $920 and the S-04 Pole Position is $804.
The choice is much sparser for the non-Sport model. The standard 225/55-17 is an odd size. Michelin does list he PS AS3 in that size and Conti has the ExtremeContact DWS. The 7.5" rim can also fit a 245/50-17, but that is also an odd size. The Conti DWS is available in that size though.
Michelin info on their tires: Shop for Ultra-High Performance Sport Tires | Michelin Tires
Conti UK video on inflation kit:
This is the less expensive Slime kit with the same functionality:
Even if you stick with the runflats, I recommend carrying the inflation kit with sealant. Running on the zero pressure runflat makes the tire unrepairable and frequently damages the rim at the same time. This is a big topic on the BMW forums that have used the same 19" size tire for years. The replacement for the runflats are very expensive.
