550 tyres - limited choice

Six years later and we still face a similar conundrum. One option I’m considering is getting Michelin PS4s 295/30/18 and 255/35/18 for my 575. You lose an inch overall in diameter (26” reduced to 25”) but ratio between front and rear is maintained. I’m wondering if anyone has ever run a slightly lower side profile tire on these cars.

 

I would advise against for several reasons. F/R balance is preserved yes but everything else will be off from speedo to odometer rate change to threshold of intervention for traction control, abs threshold to ride height to look point is, would not recommend.

In the 18in size I would get the conti. It’s what I use on my wife’s DD (that hauls around the kids), what I used on my 456m before switching to 19s, and what I run on my 6.0. Same thing I told Nick who runs the exact same wheels on his car too.
Run them a lb or 2 higher pressure as it makes their rebound and steering just a touch better.

 

I should add I run Re7rs tires on my 575. They are far superior to the PS4 in terms of performance, but come at the sacrifice of longevity and ride quality.