17" vs 18" honest viewpoints pros/cons

[Foxpuppet]

After overwhelming myself with searching for a new wheel/tyre combo for my t5 I have decided on the ronal r41 in black. Now my only real issue is to choose a size.after reading so many posts in the 17" tyre thread, and having found options to suit both sizes on tire rack, I want to know from those who have driven extensively on either size what you think of the overall practicality and comfort of 17" vs 18".
Did it make the drive uncomfortable? Did your tyres wear really fast? Did your van look much different style wise? Was it worth it? Haha a lot of things running around my head before I click ok on the wheel order. Any suggestions or pros cons very much welcome, are there things I am forgetting?
Cheers vanners!

[kaanage]

Check the tyre load ratings with the bigger rims too - lower profile tyres almost always have lower load rating for the same width due to the reduced air volume.

[Transporter]

I have 17" on my 2005 4Motion and wouldn't put it on 18" wheels, I have enough of the noise from the suspension on 17". In 2 weeks or maybe sooner, I will put on 215/60/17 instead of 55mm profile, which should reduce the suspension noise.

The handling with 235/55/17 is more than enough for road use, even under the spirited driving conditions, wet or dry.

[Foxpuppet]

I have 17" on my 2005 4Motion and wouldn't put it on 18" wheels, I have enough of the noise from the suspension on 17". In 2 weeks or maybe sooner, I will put on 215/60/17 instead of 55mm profile, which should reduce the suspension noise.

The handling with 235/55/17 is more than enough for road use, even under the spirited driving conditions, wet or dry.

will changing the profile have much effect on your speedo? i noticed in the uk they dont have a lot of van tyres in 235/55/17 but heaps of van tyres in 235/60/17 might have to recheck my choices from tirerack if thats a bigger category.

[Transporter]

will changing the profile have much effect on your speedo? i noticed in the uk they dont have a lot of van tyres in 235/55/17 but heaps of van tyres in 235/60/17 might have to recheck my choices from tirerack if thats a bigger category.

That's 215/60/17 not 235/60/17

[Diesel_vert]

The bloke at my local bob Jane reckons you only need a tyre to match the lowest load rating specified which on my placard is a 100t in the 215/65/16 category, I doubt his info though as more than enough members here have suggested otherwise.

215/65 R16C 102/100T

C = Commercial tyre.
102 = Load index for single fitments (i.e. two tyres per axle).
100 = Load index for dual fitments (i.e. four tyres per axle).
T = Speed index, max. 190 km/h in this case.

So unless you plan on fitting four tyres at the back, the only relevant load index to consider is the first one, i.e. 102.

will changing the profile have much effect on your speedo?

In regards to rolling circumference, the following tyres;

235/60 R16 104H XL
235/55 R17 103W XL
255/45 R18 103Y XL

... are not too dissimilar to each other, and not that much bigger than 215/65 R16, so the effect will be minimal.

i noticed in the uk they dont have a lot of van tyres in 235/55/17 but heaps of van tyres in 235/60/17 might have to recheck my choices from tirerack if thats a bigger category.

Unlike a passenger tyre, a commercial tyre has the suffix "C" next to the rim diameter (e.g. 215/60 R17C 104/102T or 109/107T) and, given the same size, will usually have a higher load index (increased load capacity) and require higher pressures to achieve them (typically beyond 3.5 bar or 51 psi).

In contrast, the equivalent passenger tyre size is 215/60 R17 96T or 215/60 R17 100T XL.

My queries are more on Day to day driving, noise, ride comfort, durability, handling etc.

Haven't got a T5, but for what it's worth, I predict day-to-day driving (on Sydney's roads) will be bumpy, jittery, noisy, annoying & tiring, due to the lack of compliance from the tyre and from the suspension working overtime trying to keep the tyres in contact with the road. But when you hit a smooth road, it will be absolute heaven, joy & relief.

General roadholding and grip will feel improved on smooth surfaces, but compromised on rough or uneven roads, for the same reasons mentioned above.

The durability of any passenger tyre will probably be compromised compared to any commercial tyre, as I suspect their design brief and anticipated usage will be worlds apart.

If the 18" are going to reduce the comfort level by a significant amount I will stick with the 17"

It's all very subjective - one man's sports car is another man's torture chamber.
It's something you really need to test out for yourself. Visit the dealer for a "test drive" perhaps? (sorry dealers!)

[Foxpuppet]

That's 215/60/17 not 235/60/17

Thanks Transporter, i did know yours were 215/60, the 235/55 was what i was looking at and then thought about changing to 235/60 if it gave more choices. i have settled for the 17" and now will go back to tirerack and start the choice of tyre...expect more pain in the bum questions over the next few days

[Foxpuppet]

Check the tyre load ratings with the bigger rims too - lower profile tyres almost always have lower load rating for the same width due to the reduced air volume.

The load rating is the same:
103t - 235/55/17
103t - 255/45/18
I can get a fairly decent variety of tyres from tirerack to suit either size but locally the 18" are far and few between.
The bloke at my local bob Jane reckons you only need a tyre to match the lowest load rating specified which on my placard is a 100t in the 215/65/16 category, I doubt his info though as more than enough members here have suggested otherwise.
My queries are more on Day to day driving, noise, ride comfort, durability, handling etc.

[kaanage]

The load rating is the same:
103t - 235/55/17
103t - 255/45/18

Notice you have to go wider to get the same load rating => more cost, lower profile, harsher ride, more noise. This plus the increase in unsprung weight will make the ride and handling worse on anything but billiard table surfaces.

[Foxpuppet]

Sorry using tapatalk on my iPhone so can't edit,

There is only a marginal difference in the cost of me getting the 17 or 18 wheel. I am really just trying to set my mind at ease and not wonder what I missed out on if I go with the 17" over the 18" it's mainly a cosmetic thing I suppose. Further down the track I'd like to put on the K1 suspension from preen to lower it a little and get the handling a bit nicer without sacrificing too much comfort as it is my daily driver. If the 18" are going to reduce the comfort level by a significant amount I will stick with the 17"

Has anyone got 18" here?