What's the largest size wheels I can put on my 75

[Anthony Miller]

Can anyone tell me what is the largest size wheels that I can fit to my 75. Due to the lack of decent 14 inch rubber I must upgrade, I'm looking at some late 156 T.I.wheels, 17inch. PCD is good but will they fit under the guards? Thanks in advance

[dehne]

17in will fit as a mate has them on his

[MD]

Athony,
A little thing to keep in mind for road cars in terms of ride comfort and sidewall damage...
The bigger the rim diameter size in a confined space to fit it in will necessitate the use of lower profile tyres. There is a compromise point where the lower the profile the greater the deminishing returns on ride comfort and a corresponding likelyhood of tyre wall damage and rim damage on our wonderfull Aussie roads.

I have no idea of what your expectations are so I cannot say more than the cautions above.

(Besides who wants to get into a shower of debate over this issue which it has a potential to do if I nominate a combo)

[Anthony Miller]

Cheers guys,
Dehne, what size does your mate run? Did he have to roll the guards?
MD, I hear you man, I live in Melbourne with trams and totally crap roads so I really don't want to go too low in profile.

[116gtv]

i had 215/45/17 on GTA rims on a 75 some time ago, for a short time only. they were fine after fine tuning castor but that car had big suspension and shocks. also used 10 mm spacers to clear the center bore diameter, otherwise you have to open them up slightly. however, FWD Alfa rims dont have enough negative offset IMO, and if i would have spaced them out further they would have hit on the inner guard/side skirt/front bar on full lock..

I'm running 205/50/16s right now on 16x7s which looks like it would hit but it doesnt thanks to suspensions mods, and that is as big in diameter and as low in profile i will ever go on a road 75..

[Sheldon McIntosh]

Anything bigger than a 16 looks shithouse on an 80s Alfa.  In my opinion.

[MD]

Agreed.

205's on 7" rims produces a nice steering feel (on manual rack) with little tyre roll and the 50 aspect is a good compromise in ride comfort.

Don't hold me to this as I am only speculating but as this size is not "trendy", tyre prices may be a bit more cost effective?

[dehne]

mmm maybe the 75 is a 90mdl no the the size of the rims due to looks means crap but you need a rim to match the car more so than the side

[Sheldon McIntosh]

I think 205/45/16 is the same OE size as an MX5, so there is a pretty good range of tyres to choose from too.

[pep105]

I was running 205/45/16 on my 75 with 16x7 rims with the correct offset. The ride was pretty respectable given it was used as a road car (daily banger) with slightly lowered suspension. Agree with the others wouldnt go any lower our roads are pathetic. As mentioned modern FWD Alfa mags run too much positive offset and you would need to run a different tyre size from the 156 to match the rolling diameter of the 75 resulting in a lower profile tyre.

[Anthony Miller]

Fortunately as my speedo reads over by 15% i.e. when I'm doing 100 it reads 115 so when it reads 100 I'm only doing 85, confirmed by my GPS, I can afford to go to a greater overall wheel diameter. I found a formula on wiki for determining overall wheel diameter which is
(tyre width X profile / 1270) + rim dia in inches = overall wheel dia in inches
195/60R14 would be (195X60/1270)+14=23.21 inches or 589.5mm
205/45R17 would be (205X45/1270)+17=24.26 inches or 612.2mm
215/45R17 would be (215X45/1270)+17=24.62 inches or 625.4mm

It's the offset business that concerns me as I don't want to butcher the panel work or the rubber for that matter.
Thanks for all your advice blokes, keep it coming, we love anecdotal evidence it's what forums are all about

[Duk]

I have 205/40/17 on my 75. I wouldn't personally have bought them, but I can't really complain about them either.
My preference would be for some 16x8's and 215/50 (maybe 45)/16's. 1 thing to note about most cheap rims is that they are heavy MoFo's. I have a set of old Work (Japanese brand) 3 piece wheels on my Silvia (16's tho) and they are noticeably lighter than the cheap wheels on the Alfa.
But then, I have Volvo 4 piston calipers on my car, so I'm being a hypocrite  .