Sponsored by The Tire Rack

[Helmsman]

Hey guys,

the ones that went PSS to PS4, you feel higher tire pressure is needed? Tires are great in terms of grip so no complains at all, but seems they have a bit softer side walls or is it all in my brain?

Thanks

[dparm]

IIRC some have commented that the PS4S has a more rounded sidewall profile than the PSS.

I see no reason to adjust tire pressure, that is based on the size of the tire and the weight of the car (load).

[Richbot]

I think they just ride better. I noticed no difference in the amount of pressure they want vs. PSS, if anything, a bit less perhaps because they're not as rounded

[Helmsman]

Thanks guys. 2.6/2.7 Bar now but again feels a bit too comfy, I'll give it a tad more and report back.

Cheers

[Icecreamfoo]

Originally Posted by dparm

IIRC some have commented that the PS4S has a more rounded sidewall profile than the PSS.

I see no reason to adjust tire pressure, that is based on the size of the tire and the weight of the car (load).

I actually think PS4S has more square shoulder/sidewall than PSS. for the same tire size 265/35/19, the PS4S certainly offers a wee bit more pronounced rim edge protection and sticks out wider than PSS

I switched from 3/4 worn PSS to PS4S so it's not an all-worn vs. brand new comparison; didn't make any adjustment to tire pressure level; like Richbot said, I feel the new tire's design simply provides a better ride quality

[dparm]

Originally Posted by Icecreamfoo

I actually think PS4S has more square shoulder/sidewall than PSS. for the same tire size 265/35/19, the PS4S certainly offers a wee bit more pronounced rim edge protection and sticks out wider than PSS

So I pulled up the standard (non-mfg-specific) PSS & PS4S in 255/35R19, load rating 96Y, on the Tire Rack website.

Both have a section width of 10.9" but the PS4S has only 8.9" tread width versus the PSS at 9.2". That confirms that the PS4S has a more rounded sidewall.

It's possible that they engineered in a bigger rim protector but that wouldn't be factored into the section or tread widths.

[Icecreamfoo]

Originally Posted by dparm

So I pulled up the standard (non-mfg-specific) PSS & PS4S in 255/35R19, load rating 96Y, on the Tire Rack website.

Both have a section width of 10.9" but the PS4S has only 8.9" tread width versus the PSS at 9.2". That confirms that the PS4S has a more rounded sidewall.

It's possible that they engineered in a bigger rim protector but that wouldn't be factored into the section or tread widths.

Right, I get what you mean, and certainly the hard measurement numbers dont lie either. I dont know how quite to describe it, but my eyes are telling me that the PS4S sidewall (mounted) looks "fuller" than PSS

EDIT: So I remembered reading this thread a little while back and the pics this member posted demonstrated what I am seeing...
https://f80.bimmerpost.com/forums/sh....php?t=1574777 It's more of the angle of the sidewall, from the edge of the rim protector to the edge of the tread. The PS4S looks to be more straight up whereas the PSS has a much more slanted angle; the difference is particularly striking in pic #7 of the 1st post.

in any case, didn't mean to bring the discussion off topic - the new design probably does have softer sidewalls, or maybe just softer compound at the shoulder area? I feel the ride quality is a bit softer/better too, but didn't bother to adjust the tire pressure up from what I used to have with PSS