For 18" you'll be struggle to find more comfortable UHP option than PS4/PS5. Unless downgrade to touring, but also depends on which touring tyre.

With Civic weight, the PS4 should last 40k km, maybe by the time you already used to it.

Don't own PS4 over long term, but my experience of PS5 is A LOT QUIETER than the Hankook Prime2 touring tyre before it. Vibration marginally better too.

They started to have 18" limited size options.

This is where the confusion comes, sorry about my bad loose naming reference.

I treat EHP = max performance = semi slick. When I said semi slick I'm referring to road legal EHP like Nankang AR1, Cup2, RE-71RS the limited few I can name.

Some people use UUHP as wet tyres in place of EHP when rains.

The CSC7 is 240 too. But TW is not comparable across brand, they don't use same ref tyre. Potenza Sport is rated 300, same as PS4S. No way Potenza Sport gotta last as long.

Is RE004 EHP? Tread looks like UHP, for smaller size. Then Potentlza Sport take care of larger size.

There are 2 more reasons.

If corner very hard also will get small pieces chip off. Not as bad as peeling, they looks similar. Just the chip off pieces are smaller than peeling and all around the edge of the contact patch block.

Another reason is people try to use until botak. Once hit the TWI marker, 3 issues occur. The wear accelerate, easy get puncture, and peeling. I think reason PS5 get new easier to read TWI.

Primacy4 also get small chips when tread depth down to 2-3mm.

CPC6 got own problem also. After 3 years, rubber turn stiff and brittle, regardless of mileage or tread depth. Some people get peeling, just not as wide spread as PS4. Well maybe because PS4 got more users.

I just learned not to too pamper the tyre. Want to maintain nice driving feel, have to change every 2-3 years. Leave too much tread also no use. Might as well wear them out.