18x8.5 +40 Fitment

[Berty3.0RB]

Hey guys, just wondering what kind of work is required to get a set of 18x8.5 +40 wheels onto a gen 4 wagon? I'm looking at a few options, and am thinking that I may be fine with buying a set of wheels if they require a little work to fit nicely.... The car will be at stock height for a while, but if I was to lower in the future I'd look at a set of coilovers rather than springs. Anyway, any help/pics of an 18x8.5 +40 set up would be awesome thanks in advance!

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[BillyCorgi]

Hey guys, just wondering what kind of work is required to get a set of 18x8.5 +40 wheels onto a gen 4 wagon?

You need to start working on an Engineer's Certificate
http://www.rms.nsw.gov.au/documents/roa ... 9-rev4.pdf
The wheels have a width more than 26mm wider than the widest standard rims (7 inch) and will increase the track by more than 25mm beyond the maximum specified by the vehicle manufacturer for the vehicle.

So 8 inch wide with 42mm offset is the largest wheel that can be used without notifying the RTA and updating the vehicle's registration records.

Suggest that you may seek out a photograph of a Tyre Placard from a kind owner of a Tuned By STI as these may well be the widest standard wheels fitted to a Liberty and then have a discussion with the RTA technical people.

[bigBADbenny]

^
You're going to need to roll the rear guards up at least.
Kinda depends on tyre width too so maybe start off with cheap tyres as the fitment game tends to cut the sidewalls as the clearance is sorted.
https://www.google.com.au/search?q=site ... x8.5+%2B40
Butt sag will mean you're probably quite low at the back already.
Any professional rolling service should do a good job w/o too much damage

[Berty3.0RB]

Thanks for the info guys! I didn't even think that wheels would've needed an engineers certificate, but it's good to know. Will definitely do a bit more research - do it nice, or do it twice aye!

[HardwareBoB]

You need to start working on an Engineer's Certificate
http://www.rms.nsw.gov.au/documents/roa ... 9-rev4.pdf
The wheels have a width more than 26mm wider than the widest standard rims (7 inch) and will increase the track by more than 25mm beyond the maximum specified by the vehicle manufacturer for the vehicle.

So 8 inch wide with 42mm offset is the largest wheel that can be used without notifying the RTA and updating the vehicle's registration records.

Suggest that you may seek out a photograph of a Tyre Placard from a kind owner of a Tuned By STI as these may well be the widest standard wheels fitted to a Liberty and then have a discussion with the RTA technical people.

TBSTi is a 7.5", so 8.5 is should be ok.

[BillyCorgi]

Are we able to get a photograph of the tyre placard off a TBSTI Liberty?
Is a TBSTI Liberty owner able to help us out?
Is there a kind TBSTI owner who may oblige?

Bezzza is selling his TBSTI Wagon. He has been asked for a photograph of the tyre placard from his car.

[BillyCorgi]

Well indeed, HardwareBosb is correct (thank you!)
Reidy has posted a photo of the tbSTI Tyre placard. viewtopic.php?f=10&t=31248

The tbSTI had 18 x 7.5 inch rims.
This is the largest "standard" wheel offered on the Gen4 Liberty.
So, one could argue that a Gen4 Liberty should be able to run 8.5 inch rims without the need for engineer's certificate and updating the registration documentation.

What then remains is question is what offset is permissible without engineer's certificate and updating the registration documentation.

There are two caveats that override this width.....
in the RTA document it states two cases.
Front wheel drive vehicles
Except where the original manufacturer provides to the contrary, front wheel widths shall be no more than 26mm
greater than the widest optional wheel offered by the vehicle manufacturer. This requirement also applies to fourwheel
drive vehicles with constant front wheel drive.
Four wheel drive vehicles
Except where the original manufacturer provides to the contrary, the maximum width of front wheels is the lesser
of the maximum width for rear wheels or 204mm (8 inches), the front and rear wheel widths must be the same.

Also, there is a note.....
Note: 25mm increase in wheel track limit also applies

As the Subaru is am All-Wheel-Drive (or Constant Four Wheel Drive) vehicle, at face value this clause suggests that the maximum wheel width on a Subaru is 8 inch?
Offsets of +40 may also be out due to the 25mm wheel track increase limit .

I would be talking to the technical department at the RTA or the state equivalent before I parted with my money on new wheels?

[Berty3.0RB]

Well indeed, HardwareBosb is correct (thank you!)
Reidy has posted a photo of the tbSTI Tyre placard. viewtopic.php?f=10&t=31248

The tbSTI had 18 x 7.5 inch rims.
This is the largest "standard" wheel offered on the Gen4 Liberty.
So, one could argue that a Gen4 Liberty should be able to run 8.5 inch rims without the need for engineer's certificate and updating the registration documentation.

What then remains is question is what offset is permissible without engineer's certificate and updating the registration documentation.

There are two caveats that override this width.....
in the RTA document it states two cases.
Front wheel drive vehicles
Except where the original manufacturer provides to the contrary, front wheel widths shall be no more than 26mm
greater than the widest optional wheel offered by the vehicle manufacturer. This requirement also applies to fourwheel
drive vehicles with constant front wheel drive.
Four wheel drive vehicles
Except where the original manufacturer provides to the contrary, the maximum width of front wheels is the lesser
of the maximum width for rear wheels or 204mm (8 inches), the front and rear wheel widths must be the same.

Also, there is a note.....
Note: 25mm increase in wheel track limit also applies

As the Subaru is am All-Wheel-Drive (or Constant Four Wheel Drive) vehicle, at face value this clause suggests that the maximum wheel width on a Subaru is 8 inch?
Offsets of +40 may also be out due to the 25mm wheel track increase limit .

I would be talking to the technical department at the RTA or the state equivalent before I parted with my money on new wheels?

Thanks for all your help dude! I've actually gone and bought a set of Ultrex RS rims after reading your posts (they're 18x8 +42 - so wouldn't need an engineers cert.) , fitment and look is exactly what I was after. I'm sure that the extra half an inch would've meant that I would've had to roll the guards just to be safe if I bought the DTM's, but luckily no scrubbing with the RS'

Really appreciate your help tho! Will post a pic of the car once it's had a wash!