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Wheel Offset, what you need to know

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One thing I get asked a lot is what VW wheel offsets are and how to work them out.

 

The first thing I'll add is a link to one of the easiest to read calculators I've found online:

http://www.1010tires.com/Tools/Wheel-Offset-Calculator

 

Wheel dimensions are funny things, partly in millimetres and partly inches, so are a truly international blend of confusion.

Obviously everyone is aware of wheel diameters and widths being in inches. The width of a passenger car wheel is often referred to as J (e.g. 8J X 19) which is an industry marking to do with bead profile and not something I'm here to bore you with.

Also on wheel markings/stampings you'll often see an H along with possibly another suffix too, this is quite simply for the hump in the wheel which is positioned to increase the strength of the wheel, e.g. H2. Google is your friend here if you're interested in specifics or this post will just get bogged down with pointless info.

 

Then we have the PCD, the Centre Bore and the Offset. These three things will determine whether your wheels will fit your hubs and the latter will be the deciding factor as to whether the wheel will physically fit in the wheel arch.

 

Offset

This is measured in millimetres and referred to as ET (einpresstiefe which is the German for insertion depth).

The Golf (& Scirocco) are based on FWD chassis despite the former's R models being 4WD.

FWD cars tend to have what's called positive offset (this helps with keeping the wheels pointing straight ahead when moving and aids stability).

If you have a look at the wheel diagram on the link I posted it shows how offset is calculated. There's an imaginary line running down the middle of the wheel profile and the offset is the distance between this and the rear of the hub mounting.

 

In very simple terms when dealing with modern passenger car VW's the lower number ET means the further the wheels will stick out, or in current fashion terms "stance" or "poke".

Lower ET = more poke. Or in English the wheel face will stick out more.

 

How much is too much? I can't really answer that as there are a lot of variables and whatever I state here someone will argue the case that they've done bigger and better.

In layman's terms if you want to fit bigger or wider wheels, or even just change the offset by fitting spacers there's a certain amount of room to manoeuvre before you have to resort to more drastic things like changing the suspension geometry and flaring the wheel arches themselves.

 

Factory wheels on a mk6 Golf R are 7.5 x 18 with an offset of 51 or 8 x 19 with an offset (ET) of 50

The mk7 Golf R gets much bigger wheel arches so the 7.5 x 18 wheels get a whole 2mm less offset at ET49 and the 8 x 19 wheels keep the same offset as the mk6 R at 50mm.

 

If the reason you're putting wider wheels or spacers on the car is purely to fill out the wheels arches (or 'stance' the car if you're down wiv da kidz) then how little offset is too much? I can't answer that as different people have different opinions and different uses for their cars. 

If it's an occasional driver or used for static show displays and MaccyD late night cruising then I guess your version of filling the arches will be different to someone who needs to drive in rutted lanes or potholed urban rat runs that are infested with speed humps. 

 

As a guide I'll say that an 8" wide wheel on a mk6 should be ideally around ET44 but I've personally got away with ET41 using 235 tyres on a non lowered car.

 

With a mk7 you have much more wheel arch space to play with. You can get away with ET40 on the front and probably ET35 on the back or possibly even slightly lower offset, again using an 8" wide wheel.

With an 8.5 inch wide wheel I'd say ET45 and maybe slightly less ET at the rear. BBS seem to prefer ET46 on a mk7. I've never tried 8.5 wheels on a mk6.

 

PCD & Centre Bore

As far as mk6 and mk7 Golfs are concerned (plus Sciroccos and Passats etc) then the magic numbers here we need to see are 5x112 for PCD (Pitch Circle Diameter) which refer to the bolt holes.

And our wheels require a 57.1mm centre bore. This is the hole that runs through the centre of the wheel and is needed to mount the wheel squarely on the hub so that you don't get vibrations and wheel bolts that undo themselves randomly (or even snap). Centre bore can be higher so long as you fit a spigot ring to reduce the hole to 57.1mm

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Hi guy's 

 

Anyone run 225 40 18 Goodyear tyres on a 8.5" wide rim.

if any pics that would be most grateful also.

 

I have 4 brand new good year tyres  and a set of new 8.5" wide rims ready  for winter 

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Hi guy's 
 
Anyone run 225 40 18 Goodyear tyres on a 8.5" wide rim.
if any pics that would be most grateful also.
 
I have 4 brand new good year tyres  and a set of new 8.5" wide rims ready  for winter 

Not quite 225’s but 235’s on 8.5 j rim
55f18872385500dab162accd89723820.jpg

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22 hours ago, Jon R306 said:

Anyone run 225 40 18 Goodyear tyres on a 8.5" wide rim.

 

Not really a good idea, as the rims are 216mm wide so there will be a little bit of "stretching." Since this fitting is not recommended by tyre makers it could - just could - invalidate your insurance were it even remotely likely to be the cause of an accident. You may therefore be better advised to exchange the 225s for 235s if you possibly can. Or the 8.5" rims for 8". Either option will give you an "approved" tyre/rim match.

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26 minutes ago, Leo9 said:

 

Not really a good idea, as the rims are 216mm wide so there will be a little bit of "stretching." Since this fitting is not recommended by tyre makers it could - just could - invalidate your insurance were it even remotely likely to be the cause of an accident. You may therefore be better advised to exchange the 225s for 235s if you possibly can. Or the 8.5" rims for 8". Either option will give you an "approved" tyre/rim match.

Cheers Leo9. ..good observations.

 

Think I'll sell the 225 winters at a small loss and buy 235 to be more in the safety bracket as you say.

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16 minutes ago, Jon R306 said:

Hi mate what offset are your rims with the 235 tyres please? ???emoji7.png

Sent from my SM-J320FN using Tapatalk
 

Hi Jon

 

The offset on those is 47

 

I've decided they will be going on the R come the colder weather.......just need to order some VW centre caps as the R caps are too small to fit.

 

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Hi Jon
 
The offset on those is 47
 
I've decided they will be going on the R come the colder weather.......just need to order some VW centre caps as the R caps are too small to fit.
 
Thanks man

No rubbing or issues?

I've bought 8.5" et45 and going 235 40 like your set up so hoping no rubbing when lowered a little on eibach springs.

Much appreciated
Jon

Sent from my SM-J320FN using Tapatalk

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Thanks man

No rubbing or issues?

I've bought 8.5" et45 and going 235 40 like your set up so hoping no rubbing when lowered a little on eibach springs.

Much appreciated
Jon

Sent from my SM-J320FN using Tapatalk



Not had chance to test fit yet but I’d imagine the R like the RS3 will be ok.

If I get time this week I might try one on the R.

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7 hours ago, veneeringman said:

Hi Jon

 

The offset on those is 47

 

I've decided they will be going on the R come the colder weather.......just need to order some VW centre caps as the R caps are too small to fit.

 

 

Good plan - keep those Spielberg’s away from any salt & grit.

 

Had suspicions that on the S3 cars with mag ride sat higher than non mag ride cars, does the same apply to Golf’s with DCC ?

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I have bought rse11 18" 8.5 et47 with 255/35 18 advad ad08, no rubbing at all on my R with DCC. And Im lowered on eibach spring.

 

i think that is max tiry/size combo to fit without rubbing

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