Poon

Hi Guys,

I have searched for "ET55", there posts come up, results inconclusive.

My question is this:

I have seen a set of 911 alloys (lightweight) on eBay and the seller has informed me that the Et's are 52 and 55, I know that the 52 on the front is Okay, but what about the rear ET of 55, will they fit? I don't really understand ET's that well but commonsense tells me that if I had a 10mm spacer they would match the offset of a ET65, or without be 10mm inset from a ET65 alloy. Does this also mean that a 285mm tire would be okay i.e 20mm = 10 mm on o/s.

Hope this makes sense.

BTW, my car is a narrow body.

TIA

max911

offset o/s - ET - Einpress Tief (PUSHED IN DEPTH )

a 10mm spacer would change the offset from 55mm to 45mm.

I would try to explain, but would just confuse you...and probably myself!!
I will let the diagram do the talking.

max


http://members.rennlist.com/1976c38/...AQ-diagram.gif

Edit..OK, a short explanation:
If the wheels are ET 55, this allows the tire/rim to be "pushed in" 55 mm. If you ADD a 10 mm spacer, this will allow the tire/rim to be "pushed in " only 45mm

Edward

Poon,

Sorry, I'm not sure I even know what your question is? I'll take a stab at it; just ignore anything that isn't relevant

55mm is the OE offset (same as "ET" as Max said) for Porsche 7x17 and 9x17 rims. Now you don't mention the diameter so I'll assume you're talking about 18s since you're mentioning putting 285s on the rear. I'll further assume you're referring to 8x18 and 10x18 so if not the case, ignore me. There was just a post where someone put 285s on the rear of their narrowbody and all fit fine. So if your question is can you fit a 285 mounted on a 10x18 with a 55mm offset on the rear of a narrowbody, the answer is most likely not. You'll need a 65mm offset to put a 10x18 rim on the rear of a narrowbody. A 55mm offset would put the tire too far "outboard," probably resulting in rubbing.

Edward

Poon

Max and Edward

Thanks for taking the time to respond, I now understand that it is the distance the rim is pushed in and not how far its sits out from the hub.

This is the text from the ad on eBay and a picture of the alloys, shame they wont fit!

SET OF 4 18" FORGED LIGHTWEIGHT RACING ALLOYS FITTED WITH 2254018 PIRELLI P ZEROS ON FRONT WHICH HAVE 7MM TREAD AND ARE LIKE NEW AND 2753519 PIRELLI P ZEROS ON REARS WHICH HAVE 5MM TREAD, FRONT WHEELS ARE 8X18 AND REARS ARE 10X18. WHEELS ARE MINT EXCEPT FOR SLIGHT KERBING ON ONE WHEEL WHICH WILL BE TIDIED BEFORE DEPATCH. THESE WHEELS COST £4025 AND HAVE HARDLY BEEN USED. THE WHEELS TAKE STANDARD PORSCHE CENTRE CAPS AND THEY ARE PRODUCED BY TEAM DYNAMICS. WILL FIT 996/993/BOXTER/968/944 89 ON/CARRERA 4.

SLVR

Nice wheels! Given that the original offset is 65 and these are only 55, they would sit 10mm further outboard on each side than the correct offset for your car. Max911 is right, a 10mm spacer would reduce offset to 45mm which is the opposite of your requirement. However, 10 mm is not a lot and my guess is that, unless you have lowered the suspension, you should be able to fit these wheels.

If they rub (in that case the top of tire meets the inside of the fender) you could always divert to a 265/35-18 tire which theoretically is 20mm narrower, i.e. 10mm either side of the rim. (Note: thread widths for the same size tire vary and a 285 size can sport different thread widths across brands.)

sweanders

I have a set of wheels like those for sale, brand new in boxes. I bought them for my 928 but the didn't fit in the front.

Make me an offer if you want them, I've seen them on a 993 and they fit great. Lightest wheel available.

max911

Are those like the wheels that Graham is getting??
I agree with SLVR97tt, you might be able to get away using them with a narrower tire.
Coincidentally, the 55mm ET with a 10mm spacer would be just the ticket for a widebody car

max

TheOtherEric

I think everyone's already explained it, but let me reiterate. You can fit 18" 285 tires on these wheels, but the tires will stick out a bit past the fenders, which will cause rubbing if you lower your car or go over severe bumps (like at a DE event). Ask me how I know. Alternatively, you can use 265 tires and have no problems even if you lower your car. Also keep in mind that 265 rears are the recommended sizes by Porsche, and also a fat tire for a 10" rim anyway. Larger tires are more stretched out, thus losing the trapezoidal shape, resulting in questionable performance gains.

Jeff A 993

Yes, with 65 offset, 285/30's work great (and look like steamrollers).



I know, I know, I'll lower the car soon!!!

But, as I've said, the Paris-Dakar look is growing on me...

David in LA

IMHO rather than compromise and limit your choice of tires in order to fit a set of rims with the wrong offset, you should get the right rims with the proper offset first and then have the flexibility to experiment with different tire sizes and brands. FYI, one of my cabs has 285s on 11" rims in the rear (no idea what the offset is but it was posted on an old thread) and it looks like I can fit 295s and perhaps even one size larger.