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Wheel offset
Posted: Tue Jan 05, 2016 12:21 am
by Jessegroves
Hey guys, looking to buy some new wheels soon, Just took my old hayashi wheels off my car, just wondering what wheels you guys run and the offset? I believe my old ones were +0 and they poked out of the guards a lot, I also don't want an offset that will tuck them too far under the guards like the stock daisy wheels I'm currently running.
What do you guys run? Pictures would be great aswell
Thanks
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Re: Wheel offset
Posted: Tue Jan 05, 2016 12:58 am
by smy0003
Offset alone can't tell you how far a wheel will stick out from the hub. Wheel width is also important, a 6" wide wheel with +0 offset will sit further in than an 8" wide +0 wheel by 1 inch.
I have 15x6.5 +35 mazdaspeeds:


They could stand to be 10-15mm lower in offset looks-wise.
To my eyes the 14x7 +19 rpf1 I mentioned in your thread is perfect.
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Re: Wheel offset
Posted: Tue Jan 05, 2016 8:25 am
by hks_kansei
Offset is a measure of how far off centre the mounting face is
on a 0 offset wheel it is dead centre, a positive offset means the wheel has a deeper inner than outer, a negative offset the opposite.
The offset is millimetres off centre.
Say you have a 7inch wide wheel, or 178mm wide in metric.
with a zero offset the inner barrel is 89mm and the outer the same.
if it were say a +35 offset the inner barrel would be 124mm and the outer 54mm
Re: Wheel offset
Posted: Tue Jan 05, 2016 9:04 am
by speed
Google wheel offset calculator and you can input your specs and see how it changes the wheel location.
Unless you want peeps to just add a bunch of numbers.
Mine are 15 x 8. ET +30
Re: Wheel offset
Posted: Tue Jan 05, 2016 11:52 am
by KevGoat
May be worth some consideration that the maximum allowable change in offset is 13mm each wheel. IIRC the NA's stock offset is +45mm, so +32mm is the max can "legally" go to ...
Starting from there, you can make up further guard fill by going to a wider wheel/tyre combination, as long as it doesn't start to foul any inner arch/steering components etc, and still remain legal.
So, getting my trusty calculator out (this user is usually the stuffer upperer) ...
going from the stock NA width of 6" +45
to width 7" +32 -- would give you roughly 25mm wider outer fitment with similar inner guard fitment to stock
to width 8" +32 -- would give you roughly 38mm wider outer fitment with approx 13mm extra inner guard protrusion
Geez I hope I got that right

Edit: just my own point of view, from what I've seen on here and around the traps, most 7's with a reasonable offset, say down to +28ish, seem to sit quite nicely on a stock height to mildly lowered car. All 8's I've seen seem to NEED to be lowered, otherwise the car looks like a giant roller skate ....
Re: Wheel offset
Posted: Tue Jan 05, 2016 11:59 am
by smy0003
That's correct, except NA6 daisies are 5.5" wide so,
width 7" +32 -- would give you roughly 31mm wider outer fitment
width 8" +32 -- would give you roughly 44mm wider outer fitment
Re: Wheel offset
Posted: Tue Jan 05, 2016 12:04 pm
by KevGoat
Ah damn ... knew I'd stuff something up

Re: Wheel offset
Posted: Tue Jan 05, 2016 12:46 pm
by Jessegroves
Ahh this is quite confusing for me

I've never been able to grasp how offset calculation works, would 15x7 +19 be a legal amount?
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Re: Wheel offset
Posted: Tue Jan 05, 2016 12:59 pm
by KevGoat
No. Anything below +32 is illegal (+45mm stock offset less the maximum 13mm allowed)
Doesn't mean you can't go lower, just that if you do and you are pulled over, they can defect you ...
I was luckier than you were recently. I was pulled over in one of the Christmas roadside RBT/Roadworthy checks, but they were only checking and "advising", not defecting...
Re: Wheel offset
Posted: Tue Jan 05, 2016 1:01 pm
by hks_kansei
The legal requirements are:
Diameter of the wheel (how big the wheel is)
Width of the wheel (how wide it is)
and the track width of the car (how far apart the centre of each wheel is from the one opposite, car width sort of)
Depending on the state the maximum track change is usually about 25mm, which means the wheels on each axle can be 25mm further apart, total.
That would mean each wheel offset could be 12.5mm lower (say 12mm to make it easy)
Using the rules for Victoria (since I dont know other state rules) an NA6 can legally have a 6.5inch wide wheel with a +32 offset.
Re: Wheel offset
Posted: Tue Jan 05, 2016 8:42 pm
by routten
Okay, so I am thinking of buying some Konig Dialin 15x8s from MX5 parts and running 205/50s on my NB8B.
Below are the specs from the website including a +25 offset.
My questions are:
1. Is it legal?
2. Will it fit (as stated) without fender roll if I also get MCA coilovers?
Thanks in advance for your replies.
Product Description
15×8 4×100
+25 offset
5.5kg
Flow Formed construction
73mm center bore
Clear coated finish
Cap included
Valves not included
Clears our BIG BRAKE KITS!
Fits 205/50/15, 225/45 tyres
Always check clearance during install and after car is lowered to the ground, failure to do so can result in damage, death, tyres cut on guard lips, and other bad stuff! Takes optional 73/54mm hubcentric rings also available on this website.
Tyre Size breakdown:
205/50 fits NB guard, fits NA guard with mild guard lip roll and 1.2 negative camber or better.
-225/45: Tyres fit NB guards with no mods needed given 1.5 negative camber or better, fits NA with slightly rolled guards with that same negative camber or better
Re: Wheel offset
Posted: Tue Jan 05, 2016 11:25 pm
by cookie
Technically no. As the offset at +25 is less than +32.
The 9's I have are +35 which is OK. They sit virtually identical side by side from the outside. Stupid but that's the law. Technically they will poke too far once you add camber also so you'd need tiny over fenders or flares. But then it'd look stupid as the tops would be well in the original guards anyway... if a cop is having a bad day they'll probably note it but very low chance. I had multiple encounters with the same size and not one comment about them...
Tldr not legal but compared to all other modified cars it's the least of your worries. Will work with MCA and guard roll.
Here's what 15x9 +35 look like

Here's what my old 15x8 +25 looked like.

Re: Wheel offset
Posted: Wed Jan 06, 2016 11:07 am
by Jessegroves
Most of the wheels I've been looking at are 15x7 +19/+20. Would these be legal?
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Re: Wheel offset
Posted: Wed Jan 06, 2016 12:04 pm
by Red Dragon
Jesse - Absorb what people are posting, anything under +32 is illegal
Re: Wheel offset
Posted: Wed Jan 06, 2016 12:10 pm
by smy0003
In Vic and SA everything is illegal.
The cops won't look twice at a 15x7 +20 with a reasonable ride height. You got pulled up on the 15x8 +0 because they look obviously out of place, you'll be fine with 7" +20.
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