I had an opportunity to grab a set of the 255/35 R19 and 275/40 R19 for a very good price but I may just wait and replace the cup 2's with the PS4s once the wear out.
No...I would get the wheel and tire combo.
255/35-19 isn't big enough in terms of load capacity at any given inflation pressure. If I were you, I'd pass that opportunity up.
I would only use them for daily driver/winter and no tracking.
They're still 4 Load Index number too small, which would certainly apply in any street duty. At your door-sticker recommended inflation pressures, they'd actually be several psi underinflated. And your TPMS would never know this.
Okay but why are they offered on the base Mach1's non-HP? Is there something I am missing?
I for one am unclear which tire you picked up in those sizes PS4, PS2, something else?
My bad the sizes are 255/40 R19 not 255/35 R19 (for the 19 Bullitt) and 275/40 R19.
A 275/40x19 is 4.9% larger in diameter than a 315/30x19 which exceeds the maximum variation of 3%.
I don't think 255/35 in 19" is offered on any Mach 1 trim. It'd be wide enough, but it's not tall enough (think sidewall height) to contain sufficient air volume, which is primarily responsible for determining load @ psi ratings.
You are correct and that is why I pointed out my mistake that it was actually the 255/40 R19 and not the 255/35 R19's.
The sidewall height is only 2 mm different between 255/35 and 305/30, do you think it's enough to matter? The load index is 96Y for 255/35 while 255/40 has 100Y, but load index 96 means maximum load 730 kg per tyre, while 100 is 800 kg. It doesn't seem to me like a big difference for any scenario (well, jumping with the car aside)?
It's not about maximum load capacity once we're dealing with a specific car. Max load capacity is a tire design criterion, not a vehicle need or requirement.
