Offset question

Reply Subscribe

Thread Tools

Search this Thread

Feb 5, 2002 | 12:35 PM

snwguy

Thread Starter

New Member

Joined: Jan 2002

Posts: 461

Likes: 0

Offset question

Im still waiting for my 2002 1.8 T (sport package) and I want to change wheels. The standard size is 17X 7.5 with 235/45/17 +45MM offset. If I go with a 17 X 8 that will add .25 inches to either side of the centerline or an additional offset of +6mm. Therefore I believe I should get a wheel with an offset of 39 or close to it, if I don't want to change the original config.

Is that right ???

Thanks

Feb 5, 2002 | 01:27 PM

CraigB

AudiWorld Expert

Joined: Mar 2000

Posts: 25,477

Likes: 0

Sounds about right, but most aftermarket 17x8s are ET35, which works fine

Feb 5, 2002 | 04:06 PM

snwguy

Thread Starter

New Member

Joined: Jan 2002

Posts: 461

Likes: 0

Re: Sounds about right, but most aftermarket 17x8s are ET35, which works fine

Just tried the offset calculator

and it's telling me that

if my current wheel is 7.5 inches +45 mm offset
and I was to go to an 8 inch wheel with +35 mm

then

The clearance from stut housing to the inside of the wheel will be 4mm MORE
The outside edge of the wheel will EXTEND an extra 16mm. Does this make sense ????

What effect will additional offset have on a cars ride/performance?

Thanks

Feb 5, 2002 | 05:20 PM

WClark

Member

Joined: Mar 2000

Posts: 3,511

Likes: 0

some measurements

I measured the hub mount plane to inside lip and inside sidewall on the following 2 wheel/tire combos:

1)18x8 ET35 SSR Integral / 225/40 Michelin PS

2)16x7 ET45 OEM Sport / 205/50 Pirelli P6000

I got the following:

1) rim - 151.5mm tire - 152mm

2) rim - 148.7mm tire - 154mm

You can see with these combo I get a couple more mm tire clearance inside with the wider rim even though the inside of the rim is about 3mm closer.

How do those compare to your calculator?

Feb 5, 2002 | 05:28 PM

snwguy

Thread Starter

New Member

Joined: Jan 2002

Posts: 461

Likes: 0

Re: some measurements

Here is the URL of the offset calculator that someone posted

http://toy4two.home.mindspring.com/offset.html

When I punch in the numbers it gives

The clearance from stut housing to the inside of the wheel will be 3mm LESS
The outside edge of the wheel will EXTEND an extra 23mm

Feb 6, 2002 | 02:40 AM

WClark

Member

Joined: Mar 2000

Posts: 3,511

Likes: 0

matches pretty good - to the wheel measures

Handling...The only negative comment I have regarding handling is some tramlining I feel with the 225 not there with the 205 setup. I dont know if the offset plays any part of that or if it is simply the added tire width.