Intrigued by this thread because I am looking to do the same thing. One question though, you mentioned above that the 245s require an 8 inch rim. However, I believe the rim width of the 20" oem wheel is just 7.5". If so can you "shoe horn" the 245s onto a 7.5" rim without consequences? Thanks in advance.

 

Just checking in to see is you have had any issues with the 245mm tires on your 20" wheels. I am contemplating doing the same thing. My 350h is arriving next week and it has 20" wheels as well. The Pirelli Scorpion AS3 is a great tire. I have them on my current car in a 235x60x18. I'm a lttle concerned about how comfortable the AS3s will be in a 50 profile tire. But they surely must be an improvement over the oem Bridgeston runflats. BTW, any issue that you are aware related to a non-oem size tire voiding the warranty? Thank You in advance.

 

Good Luck - Pretty big difference 1.2" CIRCUMFERENCE INCREASE




YMMV,
MidCow3

 

I haven’t done it to my NX but I did on my Audi SQ5. I went from 255/45/21 to 265/40/21. You may need to go one aspect ratio down when going up on the width.

 

Thanks for your input! Unfortunately, in my situation going to a 45 aspect ratio takes me even further away from the oem diameter. I'm thinking now of sticking with the oem size but rolling the dice and going with the Yokohama Geolander X-CV. It's a new tire so not a lot of data available but early impressions are very favorable.

 

Going with a wider tire slightly increases your diameter on the stock rim. Going down one on aspect ratio is done to mitigate that slightly.

 

Understood, thanks!

 

I no longer own the 22 350 NX Lux (thank god) move to a Cadillac Lyriq Luxury 2 RWD, unbelievable car, zero problems. Read my reply, it clearly states the NX 20 inch wheels will accept a tire requiring a 7.5 to 8.5 tire. The 245/50R20 Pirelli Scorpion AS Plus 3 improved everything, handling, road noise and RIDE. Took them off and put the sorry Bridgestone RFs on when I got rid of the NX. As to the comment stating "the big difference in circumference" it's actually a small difference. Bottom line is they are great tires (now in my garage with about 4,000 miles on them). Sorry it took so long to reply but three tornados on 10/9 and the south side of hurricane Milton on 10/10 did a number on power, TV, internet, homes and etc. in my area--------------------at least 11 killed within 1/4 to 1/2 mile of me. Hope you have better luck with your NX than I did. BYW I don't monitor this form, only replying because you PMed me.

 

Glad to hear you are safe and back after what must been a very harrowing experience! You must feel fortunate.

Okay, I picked up the new NX350h just 4 days ago, and so far I'm not hating on the Bridgestone runflats quite as much as I thought I would, especially given that they are not yet broken in. They aren't too loud and are fairly reponsive. But it's early as the tires and me have not seen rain nor snow - but that's coming - soon. The big negative with the Bridgestone RFs is how the tires handle bumps and crevices. The ride can get rough and when in a turn or a curve and you hit one the car can get loose. That's probably not going to change. So they will be switched out sooner or later. Problem is, I don't know how much of the rough ride is attributable to the Bridgestone tire itself vs the 50 series aspect ratio required on the 20" rim. You say you solved the problem by upsizing to a 245mm width which opened up a lot more tire options - including the sublime Pirreli Scorpions AS3 Plus. I believe you because the car I traded had those same tires - but in a 235x60r18 size. But for some reason I'm still loathe to change the tire size on the NX, which leaves me with rolling the dice on the Yokohama X-CVs. I'll let you know what I end up doing. I think either option will certainly be a big improvement.
Continue to stay safe and enjoy the Caddy! That vehicle is pretty much at the apex in terms of technology and comfort coming out of Detroit these days.
BTW, I gleaned from your posts that you were not too happy with your NX. Did you have problems?