Tom2769

So I've searched and found a LOT of threads on spacers/offsets, but none specific to my set of factors. TLDR: Can I run 18mm rear spacers on a 996.1 with stock 18" twist wheels (18x10 ET65) without rolling the fenders?

Details: I have a 996.1 with stock (not rolled) fenders and stock 18" twists 18x10 ET65. It's lowered on Ohlins R&T coilovers at ~30mm drop. I am looking at a set of second hand wheels with rear specs of 18x10 ET47. This would push the wheels out 18mm past stock offset of ET65. I know from experience I can run 15mm spacers in the rear with 65 offset wheels. Can I fit another 3mm? The only forum proof I've seen of spacers (or equivalent offset) of 18mm or more on a 10" ET65 are on 996.2s or on cars with rolled fenders. I had pretty much written off these wheels when I found Apex's wheel fitment guide which claims a rear 18x11 ET60 will fit a 996 - the same fender-side offset as the wheels I'm considering (but all their pics only show this on 996.2s or race cars with possibly rolled fenders?). Anyone have experience with a 996.1 with 18mm rear spacers on stock ET65 offset or with this Apex fitment?

Tom2769

I should add: I'm running stock rear tire size of 265/35/18 and about -1.0 rear camber...

HoustonCgrBkr

I did 5 in the front 10 in the rear, I have a stock set up and tires.

wsrgklt

I think the reason you don’t see an answer to whether you can run an 18mm spacer is that 15mm gets you perfectly flush with your setup. So no one goes bigger.

Are you looking to extend out past the wheel wells?

Tom2769

No, I'm not trying to extend past the wheel wells. Just trying to determine if an 18x10 ET47 (the equivalent of stock twists +18mm spacers) will extend past an unrolled fender lip on a 996.1. 15mm spacers will get you close to "flush" on stock ET65 twists, but there is room to spare. When measured, it looks like there may be ~3mm more room there - just trying to see if anyone has experience with this issue.

wsrgklt

I think consensus in the 996 community is that 15mm spacers are perfect, but I won’t stop you from trying to figure out if you can push the boundaries.

FWIW - here’s where 15mm gets you

Tom2769

Ah, a fellow early production 1999 owner. The ambers look especially good on a black car...

Patunia

same set up on my 06/98 build. ECS tuning had free shipping.

996C438

My 99 C4 has ROW M030 suspension and I am running 15mm spacers on all 4 corners . No clearance issues even at full lock . As stated above the tires are almost flush .

hardtailer

Ready to get your hands dirty and go where no one has gone before in terms of rear wheel flushness?

Stick some home insulation foam inside the wheel well in the area of concern that sticks out so far towards the tyre that contact will occur during driving.
Do this on both sides.
The foam will be shaved off by the rotating tyre when driving.
Drive spiritely, pull some proper g's while cornering ideally on a racetrack. After you're done measure in the direction the wheel would move when fitting the spacer and check if the foam is at least 4 millimetres away from the wheel arch lip as well as any other sharp edges.
If so, 18mm spacers should work without rolling the wheel arch lips.

Edit: do the driving bit at your own risk and take your responsibility.

GC996

Tom, something to include in your equation. Tire width and camber.

You may find that you can fill up the wheel well with 15mm spacers and a wider tire. Or 18mm spacers with more camber and a narrower tire. Some 225s and 285s are wider than others. You can check the measurements on tire rack.

EVOMMM

I think 15mm gives you room to run wider rubber which comes with better benefits for your car in performance and looks