only a front suspension (maybe the spring? I don't know its part name exactly) once replaced.

I do my best on maintenance. But sometimes I cannot avoid troubles ~_~;;

Bushings on the rear arms are possibly quite soft at 140k miles. Although alignment looks good during a static state, worn bushings on control arms can allow excessive toe and camber changes when car is in motion (namely during acceleration and deceleration), causing the uneven and accelerated wear you had.

I've had the same tires before (on a 240sx, SPL arms), no issue with tire wear whatsoever.

Not only get tires changed, at the same time I also got a regular maintenance, and there was no specific problem about suspensions.

Anyway I'll refer to it. Thanks for the info.

:D

At this high mileage, there is likely issue(s) with the suspension that caused this rapid tire wear. As I stated in my earlier post, my e46 M3 had both the front and rear bushings cracked at about 40k miles. They were fairly inexpensive rubber bushings ($60 to $80 part only), but they would destroy those expensive $300 tire in a few thousand miles.

We used the same EVO tires in the G37s coupe (daily commuter) with similar sport suspension as the 370z, it lasted more than 40k miles (f & r), the rear wore out just a bit more on the inside. We just replaced them with the same tires. They are good value tires for DD.

I'd get your suspension checked out with a knowledgeable shop.

My maintenance sheet says the shock absorbors and suspensions are okay with green color checked.

Is it not enough to be knowledgeable .. ?? (just curious)

You give the competence of the average dealership tech way too much credit. That's why more than a few people have suggested taking it to a different shop before you shred a second set of tires.

Knowledgeable enough? well, the rear toe is .25/.17 (L/R)... without any preference, I would set it in the middle of the range AND the same value on both side (.15/.15).

however, it is still unlikely that would cause the rapid tire wear you experienced.

When car is static, or on a lift, worn bushings may not be apparent. Unless the bushings have obviously failed (cracked, making sounds, torn, etc), a worn bushing can pass the factory mechanic's eye test when in fact it's are already at the early/mid stage failure, enough to cause some amounts of uneven tire wear.

It's not the tire's fault. Tires don't wear unevenly for no reason.

That is the issue. My previous Ventus tires were not 'unevenly' worn out. Their left and right ere in the same condition.

They just got literally 'rapid' worn-out than I expected. That's why I had no idea for what was wrong.. ~_~;;