What Alloys do I need?

[Pauly]

I think the original point is more aimed at warranty issues, larger circumference/rolling diameter will have an effect on stresses and strains etc i have no idea how big or small this would be and if it may affect anything really but if you are unfortunate enough to get issues you have to wonder what VW would think.

 

[RattyMcClelland]

I'm more confused than ever!... All this talk about gearboxes etc. going into meltdown just because someones fitted 19' or 20' wheels?? Surely if the rolling circumference is the same or very close to a standard 18' wheel and tire why should the gearbox disintegrate? whats it made of? chocolate?

Yes it's more vw covering themselves more than anything.

But don't be confused. Large wheels won't harm the gearbox, it's not true at all.
It's true that the larger the wheel the further out the weight is, meaning more rotational inertia, there for more strain.

A bad remap killed my box within 10k miles, since it's replaced and the remap properly sorted I have ran 19s for over 50k. No issues.

The 5 speed box IS made of chocolate. It's bloody pants, spot weld on the diff fail under excess torque so any remaps have to be torque limited and delayed peak torque to a higher rpm.
6 speed box is much much better.

Other vw 5 speed boxes are pants too. My local garage is a vw specialistand the most failed gearboxes they see are 5 speed vags.

 

[CRD]

I think the original point is more aimed at warranty issues, larger circumference/rolling diameter will have an effect on stresses and strains etc i have no idea how big or small this would be and if it may affect anything really but if you are unfortunate enough to get issues you have to wonder what VW would think.

If I ever have any gearbox/drive train issues with my van during its warranty period, you can be sure the original 16's will be going back on before the dealer sees it.

 

[Pedro]

Never sell the originals.......
For sentimental reasons obviously

 

[DaveBos]

Ran 20's (275/40/20 tyres) on a T5 for 5 years, 70k miles, no problems.

 

[Caravellet6]

I guess weight and surface area of wider tyres comes into it as well? I'm no expert but I ran 19" wheels with wider lower profile tyres on a 25 year old T3 on its original auto box with no problems. The only reason in not messing with mine is that it's under warranty and worth ten times more!

 

[chriscroft]

I do have some experience of over sizing; imo in terms of drivability i.e. effect on gearing=stress on gearbox, if you are not max loading it, and you have a decent power/torque output from your engine; the nan increase in rolling radius of say 4% is fine, and it won't even upset dsg if you have it. I have gone upto 7.5% increase, with a tunes 174hp engine; and I do not recommend it, in terms of messing with the gearing, and change points etc etc.

One stange anomaly I spotted in the caravelle brochure on the 17" wheels is the tyre sizing 17" available with 235/55/17 = vw standard rolling radius for a t6; or 215/65/17 tyres = +2.9% seems a bit odd

So imo if you use a tyre size comparison app stick to about +4% over a 235/55/17 size then no drama. Also many VW T6 have a gross train weight of 5.2t/5.3t, so not only can they carry a shed load ; they can also pull 2.5t , with a roof rack, up the alps at 80 miles per hour so I wouldn't worry too much about these things.

Big question is tyre pressures, and amount of side wall to take up the pot holes. If you can find a tyre with a higher load rating in the size you need, i.e. say 106xl/108 etc etc you can run at lower pressures and let the side walls flex a bit.

 

[chriscc]

I'm a complete novice when it comes to vans but having received mine with 20's on (275/40) I found the ride to be surprisingly acceptable.
Admittedly the two other cars I drive are low and have firm suspension, so you notice every bump and tramline.

I've just put the factory 16's (215/65) on and the ride is a lot "bouncier" and has more roll.

As I'm not sold on the look of my 20's I'm going to sell them and enjoy perusing some black ones instead - maybe in 18's this time.

 

[former member]

@CRD ; don't you think that's rather deceitful? Like taking off a remap then complaining the gearbox (or other drivetrain item) has gone pop.

I guess you'd happily sell it to another enthusiast with the 16s back on?

Having been stung by a Defender that had been ragged then sold as Used Approved, I'd never touch anything with and sign of modding.

As a proper enthusiast and general car nerd, I've done tonnes of research into bigger wheels and ultra low profile tyres; all of it points simply to vanity.

And it's a Brit thing.

The coolest vans I saw while away were raised on small wheels, proper 4x4 tyres and looked ace.

 

[CRD]

@CRD ; don't you think that's rather deceitful? Like taking off a remap then complaining the gearbox (or other drivetrain item) has gone pop.

I guess you'd happily sell it to another enthusiast with the 16s back on?
.

Deceitful? To who? Those paragons of virtue VW? Come on now.

Sell it on to another enthusiast? Well, I don't ever plan on selling it on so hadn't really considered it tbh. But if I ever do sell it on, It will most probably be sold as seen with at least 120,000 miles on it as I will be using it as my daily driver for 4 years at 30k p/a approx.

 

[CRD]

@CRD

The coolest vans I saw while away were raised on small wheels, proper 4x4 tyres and looked ace.

Oh, and another thing, you should never take opinion as fact.

 

[Mojo]

I think the original point is more aimed at warranty issues, larger circumference/rolling diameter will have an effect on stresses and strains etc i have no idea how big or small this would be and if it may affect anything really but if you are unfortunate enough to get issues you have to wonder what VW would think.

Cheers Pauly, agreed, that seems to be the real crux of the issue, just about every T5 and most T6's I've seen have bigger wheels than standard, if they're all about to go pop VW better up the production of gearboxes pretty sharpish...

 

[Mojo]

Thanks everyone for posting some very helpful info on this thread... much appreciated

 

[Mojo]

The coolest vans I saw while away were raised on small wheels, proper 4x4 tyres and looked ace.

Have you got any pics? would like to see them, where is this trend most common? Cheers!

 

[Mojo]

@CRD ; don't you think that's rather deceitful? Like taking off a remap then complaining the gearbox (or other drivetrain item) has gone pop.

I guess you'd happily sell it to another enthusiast with the 16s back on?

Having been stung by a Defender that had been ragged then sold as Used Approved, I'd never touch anything with and sign of modding.

As a proper enthusiast and general car nerd, I've done tonnes of research into bigger wheels and ultra low profile tyres; all of it points simply to vanity.

And it's a Brit thing.

The coolest vans I saw while away were raised on small wheels, proper 4x4 tyres and looked ace.

Hmm, is this what we're talking about? just found these...

 

[former member]

That kind of thing.

CRD; a few facts.

Oversized wheels are heavier.
The ultra low profile tyres designed for high performance cars not 2.0 diesel vans give a rock hard ride and tramline. A van does not even remotely need more lateral grip than you get from even 16" OEM tyres.
Tyre choice is much more limited.
You can't carry a full sized spare. I can.
Oversized wheels are a fashion fad that offer no benefit to anything but ultra high performance cars.
Oversized wheels are often weaker. Look at BMWs issues with 19"'rims.
Oversized rims need ultra low profile tyres to maintain rolling radius; on a van?!
They are less efficient and create excess drivetrain wear.

Of course it's your van, do what you want with it but I just cannot see why the above issues are ignored for vanity. Never have, never will.

 

[Mojo]

I've got to honest, I like the 'off road look' as much as the large wheel/lowered look, but I'd probably be just as paranoid that those knobbly tires where creating extra rolling resistance/drag/noise etc. Where does it all end? Lol.

 

[former member]

@Mojo - Quite a few aren't too knobbly - the Michelin Crossclimates on our Subaru Outback are fairly quiet but work in ice, snow, rain and (some) mud.

One T25 I saw had a Subaru 2.5 engine (same as our Subaru car), was raised, has custom chassis and brakes made up and looked ace. Proper off road adventure mobile.

And a German Sprinter conversion - again raised, on hardcore tyres, snorkel fitted and loads of kit. Proper Apocalypse vehicle!

 

[CRD]

That kind of thing.

CRD; a few facts.

Oversized wheels are heavier.
The ultra low profile tyres designed for high performance cars not 2.0 diesel vans give a rock hard ride and tramline. A van does not even remotely need more lateral grip than you get from even 16" OEM tyres.
Tyre choice is much more limited.
You can't carry a full sized spare. I can.
Oversized wheels are a fashion fad that offer no benefit to anything but ultra high performance cars.
Oversized wheels are often weaker. Look at BMWs issues with 19"'rims.
Oversized rims need ultra low profile tyres to maintain rolling radius; on a van?!
They are less efficient and create excess drivetrain wear.

Of course it's your van, do what you want with it but I just cannot see why the above issues are ignored for vanity. Never have, never will.

Polzey, I look forward to bumping into you sometime at a meet or festival where we can discuss the merits of wheels and lowered v raised suspension etc over a few beers into the wee small hours (you do drink beer I assume? ). I'm sure after you see my tastefully modified van, you will concede I have not ruined its looks entirely
I understand your point of view re. oversized wheels and ultra low profile tyres to a point, but fwiw, I am fitting what I do not believe to be ridiculously large and wide tyres- I have opted for 245 x 45 x 19 which are only 30mm greater diameter than the 205 x 65 x 16 originals.
Now, if this 4.4% increase in circumferance is enough to stress the gearbox and drivetrain so much that it fails within warranty period (my van will never be loaded to anywhere near its rated gvw max btw), then you are damn tooting that I'll be back at VW shouting at the top of my voice as I do not believe I have unduly contributed to this failure.
I'm not really worried about using the original 16" wheel as a get-me-home spare. At worst it will trigger my tyre pressure monitor and it would be a pretty harsh Policeman indeed that tried to 'do' you for having different diameter wheels on the same axle (I'm guessing width is not an issue same as for cars although haven't looked into it)

 

[former member]

Fair comments CRD and I don't think 19" 245/45 is too OTT - it's when it's 20"+ and 265++/35 (or less) that things get a bit daft.
A mate of ill fortune and general taste (IMO) stuck 22" RR alloys on his T5.1 180 - he couldn't steer to full lock, the ride was tragically poor and the next owner immediately stuck 18s on.

We've got a fair range from deeply uncool but nuclear bombproof 16s (215/60 profile All Weather tyres) on the Subaru, middle of the road 17" with 235/55 (too wide IMO but OEM) on the California and 18s (245/35 rear, 225/40 on the front) on the M135i, all as small as can fit over the brakes, all non run flat.