vrover

The rears on my 1996 C4 (not S) are worn on the inside (of course) to the point that they now require replacement.
But, the fronts are not close to being worn - they have lots of tread.

Now, I know that on a "normal" AWD car you would replace all 4 tires at once because, in theory, you would have
been rotating the tires front to back to front to back and the wear would, again in theory, be pretty balanced. You
don't want to have a big difference in the circumference of the tires.

But on the 993 C4, that's not the case. You can't rotate front to back. And since the back tires wear a lot faster,
you will always have an imbalance in the circumference except on the day you drive out of the tire shop.

So, really, isn't OK just to replace the rear tires?

The Brewmeister

That depends on the age and overall condition of the fronts. Many on this board go by the six year old rule, I believe Tire Rack recommends replacement at ten years. If you replace only the rears they should be the same brand and model as the fronts.

vrover

Yes, well, the new tires would be AS3+ and the old ones are not the same as that and they are older than 6 years for sure.

abiazis

Replace all 4 and not worry about it..........I just did....in same situation....usually the fronts outlast the rears 2 sets to one or about 30K miles to 15K miles.......Continental, Hankook, Sumitomo or BF Goodrich are good options if you don't go Michelin or Bridgestone...........depends what you want to spend with BF Goodrich the least expensive along with Hankook...and Sumitomo

Mark in Baltimore

Seeing that the tires are different types and are six plus years old, definitely replace all four. Also, I believe the AWD system needs less than a 3% circumference difference (can't 100% recall).

TheOtherEric

Speaking purely practically, replacing just the rears with a tire similar to the fronts can be ok. But it could also lead to odd handling, and would DEFINITELY be a huge black mark against you if you go to sell the car. So you have to decide if it's worth it to you to avoid a ghetto tire setup. And like Mark said, the circumference needs to be within some limit on a C4.

Brig993

I always replace all 4 YOLO.

Kein_Ersatz

All 4, false savings otherwise...

Gbos1

Worn on the inside? You need a proper alignment then from somebody who knows these cars. Shouldn’t be wearing out on the inside.

GwynnieMae

Assuming your fronts aren’t super old, replace the rears with the same model of tire as the fronts. I’ve done this many times over the last 136,000 miles I’ve put on my car. Ive found that on average, the fronts last twice as long as the rears. 15k on rears and 30k on fronts. That’s been pretty consistent for a while.

Mark in Baltimore

The OP said his front tires are more than six years old. Perhaps not super old but definitely too old. IIRC, Porsche (and many other manufacturers) recommend replacing tires that are six plus years old.

fsa

Michelin site recommends tire replacement if 10-years old. Doubtful many on this forum keep rubber that long, whether adequate tread left or not; more likely 5-6-years.

FLYT993

i've replaced the JUST the rears on my C4 a couple of times. it's fine.