955 20" Staggered wheel tyre size

[YPVS]

I have 20" Sport techno (I think) wheels on my 06 955 Turbo WLS (so pretty much S spec, including brakes).

Because of the 19" brakes, the wheels are different front to rear. The front has bowed spokes to clear the callipers and are 9", whilst the rear wheels have a slightly different offset and are 10".

Porsche though, fitted 275/40/20 tyres all round. The rears seem to pinch in a bit and leave the wheel exposed to curbing (as the previous owners have found out several times).

Now, I know we need to keep rolling circumference very similar for the 4WD system, but 315/35/20 is near identical.

Has anyone fitted wider tyres on the staggered 9" and 10" twenty inch wheels supplied on some Turbo S and WLS models?

I have one rear with a nasty chunk out of the rim protector band, but the other rear is an almost new 275/40/R20 Pirelli P Zero. I'm not sure if it would be a good time to just replace the damaged one with a matching P Zero or wait a bit nearer the MOT and swap the pair for 315/35/20's.

 

[Hatchetf15]

Same dilemma I faced. The 275 tires leave the 10" rims too exposed. Not all angles expose the visual flaw, but I always notice the pinched sidewalls. I was thinking the same as you about going to the 315, but a set of 4 AZ 850s in 275 was only $640, so...in two years I'll most likely be putting 315s on the back.

Put the 315s on the rear. They're what will make you happier looking at it. It will probably drive better. It will keep your rim bead happy. I cringe thinking of that dreaded sound!

 

[YPVS]

I've finally decided to do this.

The current 275/40/20's are a right mix match. One rear is 6mm, but puncture repaired, the other is 5mm and has a chunk out of the rim protecting band on the sidewall, which I'll worried could be an MOT fail.
The front's are some tired looking budget jobs about half worn.

I did a bit of research and ended up finding one tyre in both 275/40/20 and 315/35/20 sizes, so have ordered a pair of each to start from fresh with the same tyres all round, albeit slightly wider but lower profile at the back, giving almost identical rolling diameter. They're 106 (950KG) front and 110 (1060KG) rear, load rated, so 1900KG across the front axle and 2120KG across the rear, so plenty load rated enough and have a speed rating of "Y", so 186MPH, which is clearly plenty.

Not too bad, but still £800 fitted, for Falken Azenis FK510 SUV. These are XL rated and A rated for wet grip, with 70db noise level, which is lower than most and well reviewed. They seemed better specced and rated than the Michelins, which weren't a match in both sizes.

I'll report back when fitted. 8)

 

[YPVS]

Yep, I'm happy with these.

The drive is much smoother with 4 x matching tyres, especially pulling away, they're quieter, even though the rears are now 315mm wide and grip is pot on.

The rear wheels are protected now and not as exposed. I would definitely recommend this upgrade to anyone with the staggered 20" wheels.

 

[P911X50]

I have a set of Techart wheels 285 35 22 if anyone is interested and also a set of Mansory 295 30 22 and separately a set of 295 30 22 Pirelli Scorpion tyres
:thumbs: