there is a lot of great info for fitting Alloys here
Written by loogy
For this thread, I will be trying to keep things as simple and to the point as possible. If anyone is still unclear on certain wheel terminologies, please see the following sites for some very clear explanations.
The Tire Rack
RS Racing
So here are the facts as I see them:
Bolt pattern:
The Vanagon bolt pattern is 5x112. This is shared with Mercedes, many Audis and many VWs. Other bolt patterns can be used on a Vanagon through the use of adapters. In order to use adapters, the offset of the wheels should be 50mm or more (at least for the front).
Offset and wheel size:
Wheel size and offset go hand in hand in most cases. The ideal offset for the front of a Vanagon is 30mm through 39mm. A little more or less is sometimes okay, but it really is best to stay as close to the ideal as possible. The following is a list of wheel sizes and their recommended offsets in relation to the FRONT of a Vanagon:
- 15x6 - ET30 through ET35
15x6.5 - ET30 through ET35
15x7 - ET30 through ET32
15x7.5 - ET25 (not recommended)
15x8 - ET18 (not recommended at all - wheel will be outside the wheel opening)
16x6 - ET30 through ET35
16x7 - ET30 through ET35
16x7.5 - ET28 through ET30
16x8 - ET17 (not recommended at all - wheel will be outside the wheel opening)
17x7 - ET30 through ET35
17x7.5 - ET28 through ET30
17x8 - ET25 through ET30 (possible slight upper control arm modification needed)
17x8.5 - ET23 (not recommended)
Below are a series of illustrations showing how the Vanagon suffers from a height versus width issue when it comes to fitting wheels onto the front. The illustrations, although slightly exaggerated, clearly show how simply changing the diameter of the wheel can have a profound impact on the fitment.
***Please see the notes at the end for more information***
Centerbore:
Mercedes wheels have a 66.56mm centerbore. Audi/VW wheels have a 57.1mm centerbore. Due the large diameter of the Vanagon's front grease cap, a centerbore of at least 64mm is required. Obviously the Mercedes wheels will fit just fine but the Audi/VW wheels must have their centerbores enlarged in order to fit. I recommend that the Audi/VW centerbore be opened up to the same inner diameter of the Mercedes wheels, 66.56mm. The reason is that this gives good clearance for the grease cap as well as allows the owner of the wheels to install a 66.56 to 57.1 hubcentric ring adapter should they ever choose to sell or use these wheels on an Audi/VW again. It's nice to have options and if you are having the centerbores opened up anyway.....
Lug nuts, lug bolts, wheel studs and wheel thickness:
Mercedes wheels that originally were designed for use with 12mm lug bolts must be drilled to accommodate 14mm wheel hardware. Although a 9/16" drill bit will work for this, I recommend a 37/64" drill bit for a little more clearance around the lugs. Make sure you debur the hole after drilling.
12mm lugged Mercedes wheels and Audi/VW wheels use a small ball seat lug. Original Vanagon lugs are too big to seat properly. See the following picture for the difference.
How do you know if your wheels require the small ball seat lugs or if the stock Vanagon lugs will work? Simple! If you had to drill out the lug holes of your factory Mercedes wheels (not aftermarket) for 14mm wheel hardware, you need the small ball seat lugs. If your wheels are factory Audi/VW, you need the small ball seat lugs.
Mercedes wheels that originally came with 14mm lug bolts can be used in conjunction with the stock Vanagon lug nuts.
Each wheel measures slightly different from the base of the lug seat to the wheel mounting face. See the following illustration for an explanation. The area in question is depicted as the lighter blue arrow. This measurement must be known in order to make an accurate assessment as to the necessary length for wheel studs and lug bolts.
Measuring for rear wheel studs:
2wd and Syncro Vanagon rear wheel studs are 34.4mm long overall. 23.4mm protrudes from the hub/brake drum.
Syncro front wheel studs are approximately 45mm long overall. Approximately 23.4mm protrudes from the hub/brake rotor.
(I say approximately because I have not measured this myself. I have had to rely on others for this information)
Lug torque will remain the same no matter what wheels you are running. Lugs should be torqued to 132 lb-ft.
Centercaps:
Due to the long hub/grease cap of the Vanagon, fitting centercaps can be a challenge. If you are overly concerned about having centercaps, try to choose a wheel that has the flattest face possible. The more that the wheel is "dished" in toward the center, the less likely it is that you will be able to fit a centercap. Even with a flat faced wheel, the mounting style of the centercap may still prevent it's use.
See the following illustration to help you determine if a particular wheel's centercap might fit.
Keep in mind that there are two sizes of grease caps that came on Vanagons. By far the most common is 35mm in height. The taller version is 43mm in height. It is possible to shorten the 35mm grease cap by approx. 5mm if needed for centercap clearance. The 43mm grease cap could be shortened by 13mm.
The following photo shows the tallest grease cap on the left, the most common cap in the center and the 5mm shortened version on the right.
Note for those either running or contemplating Van-Café (SA) big brakes:
The SA big brake kit uses a hub that has different dimensions than the original Vanagon brake rotor/hub. They also use press in studs like the rear instead of lug bolts. Here are some critical specs from the SA big brake that one should be aware of when using them in conjunction with various wheels.
The SA hub tapers from approx. 60.1mm at the grease cap to 65.86mm at the mounting face of the brake rotor. This information is critical when it comes to enlarging the centerbores of Audi/VW wheels as well as the use of hubcentric spacers. I still suggest that Audi/VW wheels have their centerbores opened up to 66.56mm.
The SA hub also positions the track width (measured from mounting face to mounting face) 5mm narrower than the stock brake set-up. This means that a given wheel will mount 2.5mm (2.5mm per side) further inboard when using the SA brake kit as compared to the stock Vanagon brakes. If you're current wheel or wheel/spacer combination is really close to either the upright, upper control arm or both with the stock Vanagon brakes, it is possible that you could run into clearance issues when switching to the SA brakes.
The SA hub uses press-in studs that are 51mm in overall length. 29.7mm protrude from the hub once the rotor is installed. This information is critical when it comes to knowing whether or not a particular wheel or wheel/spacer combination will leave with enough threads to properly install the lug nuts. The knurl (spline) diameter of the SA studs is 15.1mm.
Porsche spec studs can be used as a replacement, but a tack weld at each stud head may be necessary to keep the stud from spinning in the bore under extreme conditions.
Additional notes:
Note: When installing spacers, adapters or even just changing wheels, it is usually necessary to remove the two 11mm headed bolts from the rear drums. These bolts serve no practical purpose and it is perfectly fine to discard them.
Note: Keep in mind that the higher the offset, the less clearance you will have to critical suspension components. If you plan on running a wider than normal tire, check your clearances very carefully.
Note: Spacers can only be used to correct a wheel's offset if it is too large. Spacers will not help you if the wheel's offset is too small. Only machining of the wheels can help you there.
Note: The offset does not need to be the same front and rear on a Vanagon. Sometimes it is actually better to have different offsets front and rear. The rear suspension is much less dynamic than the front and therefore is not nearly as sensitive to offset changes.
Note: If you follow the same fitting guidelines for the front and rear of your Vanagon, you can be assured that the rear will fit properly without any sliding door clearance issues. For example, 16x7 with an effective offset of 30mm (after any spacers) will work both front and rear with no problems.
Note: The offset of the wheels can affect the tire clearance greatly. More offset at the front wheels will give you more clearance to the body but less clearance to the front suspension components. Body to tire clearance is usually not a problem on the rear of a Vanagon but more offset will decrease the clearance between the tire and rear control arm as will a larger diameter. Please keep this in mind when comparing wheel and tire combinations that others have used.
Note: Syncros and 2wd Vanagons have very different front suspension parameters. Syncros can handle a much wider variation of front wheel widths and offsets. However, if you follow the 2wd front wheel guidelines, you can be assured that the wheels will fit your Syncro as well.
Well, I think that about covers it. If I forgot something, please let me know and I will add it in.[/quote]
i think i got away with it this time 
is the bus gonna drive better with them on? i think not . they do look good though, a bit like one of the new vw wheels---- that looks a bit like most other car wheels these days--ho hum