Stretched tires and long distance driving

[SwagenGti]

So I don't have too much experience with stretched tires. The first time I ran them (215/45/17 on a 10.5" wheel) one of my side walls burst on the highway during a 2 hour road trip. Tire pressure was 40 psi and it was a Falken 512. My current set up is 205/45/17 on an 8.5" wheel and 215/45/17 on a 9" wheel (nothing crazy, both tires were able to be mounted with very little help from a cheetah/fire/etc). The tires are Nankang NSII's and I am currently running 40 psi.

I have to drive home which is a 5 hour drive. I am assuming the sidewall could burst either due to random chance imperfection in the tire, too much heat in the tire due to the long driving and/or too high of tire pressure. Would it be best to bring the pressure down? My e36 M3 proper tire pressures call for 32 psi front and 36 psi rear for stock wheels. I am assuming I will be fine either way but just want to hear your opinions.

[KyleAnderson]

What's the max pressure rating on the tires?

I'm coming up with 38psi front and 41psi rear.

(originally 225/45/17 at 32psi and 245/40/17 at 36psi)
-New front volume is 18% smaller, raise pressure 18%
-New rear volume is 14% smaller, raise pressure 14%

[E.Myers]

I have nankangs 215/45/17 on a x9. Have done many long distance trips and keep psi at 35. No issues, its a very mild stretch.

[mesooohoppy]

there are a bunch of variables that make it hard (if not impossible) to pin point exactly what went wrong.

with that said, I have 225/35/18 on a 9.5. I run 32 psi in the front and 34 in the rear. I might up them a couple of pounds, but I am happy with how it feels.

im not sure if its a sacrilegious thing to suggest a slightly less stretched tire (if possible)..?

[fifty3bags]

You shouldn't have any issues. I know many people that have run more stretch than that and drive long distances.

I currently have 225/40/18s on 10.5s and 245/40/18s on 11.5s, all 4 are Nankang NS-20, for reference. My car is my daily and I have driven many times to my parents house (3.5 hours) and took a trip to Daytona which is 9 hours from me with no issues.

[jiafaiba]

Right,many people that have run more stretch than that and drive long distances.

[808e30]

I drove to Fontana from Phoenix with 215/40's stretched on 11"s 40psi no problems, just take any sharp turns slowly.