18x8 - 225/35/R18 vs 235/35/R18 for mixed-daily-track use?

[lapsio]

Hi I recently purchased 2020 BRZ Final Edition (it has Sachs suspension like TRD/Performance Package in terms of details affecting fitment guidelines) and I'm looking for some set of wheels and tires for mixed daily-track use.

I'm relatively convinced to OZ Uktraleggera matte black 18x8 ET48. However I'm not sure about tires. I've seen dude here: https://www.gt86.org.uk/forums/forum...a-18x8-alloys/

with 225/35/R18 and it looks terrible imho. Those tires are skinny af and I really don't like this look because they look like waaaay too small wheels for this car. I've also seen dude with 245/35/R18 here: https://www.ft86club.com/forums/showthread.php?t=12693

And I quite like it. However I'm really concerned about performance of such bubbly tire setup. Please note I'm complete noob and I don't know much about tires and fitment and track use. I kinda just googled plenty of topics and guides and "I heard that running too wide tire on narrow rim is no good". I got my hands on this car literally month ago.

So I'm considering 235 since they probably should be fine?... I mean like they should have less side effects of tire deformation than 245 right? I'm probably also looking for Michellin Pilot Sport 4 tires sibce they seem to be easily available in my country and suitable for both track and daily use, even in colder climates.

Before someone comments "dude try out stock rims and tires first" - well yes I will because I have to since Final Edition comes with 17" rims and 215/40 Pilot Sport 4 tires stock so I have those already for this season. But I'd prefer to leave those rims for winter tires and get some 18" wheels for summer. I want to have full wheels so I can swap them any day I want without having to schedule visit and wait 2 weeks for tire change when season ends because all services are overloaded then... Like for example now. When it's already too warm here for winter tires and whole car floats but all places changing tires are overloaded and I have to wait.

In the long run I'm planning to get dedicated track day wheels and tires (so again I can swap just for track day) but since I'm beginner I've seen many people recommending staying on high performance summer tires and just one set of wheels at the beginning of journey. So that's my plan for now. But since I will use those wheels on track as well I care about performance, not just looks.

Why not 245/40 or 235/40? Well... I think bigger wheels would make this car a bit slower, especially at higher speeds right? BRZ is already slow af. I don't want it to become any slower than it already is I guess :/ And I don't care about comfort - I love harsh ride. Unless 35 are too thin and will perform worse than 40, then I'd definitely consider them since cornering is more important for me than straight line.

So are 235/35 good tires for 18x8 wheels from performance standpoint?

[ZDan]

I'd go 225/40-18.
225/35-18 is way shorter than stock (24.1" vs. 24.7"), hence the puny look. 235/35-18 also shorter than stock, and not much selection (exactly 1 tire at Tire Rack in that size). You could consider 235/40-18, but it's a bit bigger in diameter than stock (25.4" vs. 24.7" and you're at the minimum end of the recommended wheel width (8" - 9.5") so it might look a little pooched.

[jflogerzi]

Why do 18's when 17's will be lighter. Do it right from the start and get 17x9's and call it good. 18's are just for looks on our cars.

[churchx]

No. Several good tires in EU from UUHP tire class start from 18 with no offerings in 17 sizes. There is some practical merit in this case aswell.

[TommyW]

225 40 18. If you're new to tracking don't get something too sticky otherwise the tires will mask your mistakes. Something like the Firestone Firehawk Indy 500 is good. I think they make that size. 235 and you should be going to a wider wheel plus the 225's will let the car slip a little easier.

I ran the stock tires for my first few track days and it was a good move. You want to get used to the car moving around at lower speeds rather than getting surprised with stickier tires then scaring yourself at higher speeds when you get some slip at the rear.

[jflogerzi]

Originally Posted by churchx

No. Several good tires in EU from UUHP tire class start from 18 with no offerings in 17 sizes. There is some practical merit in this case aswell.

Stand corrected. Used to our USA market.

Sent from my GM1915 using Tapatalk

[lapsio]

Originally Posted by jflogerzi

Why do 18's when 17's will be lighter. Do it right from the start and get 17x9's and call it good. 18's are just for looks on our cars.

Well yes but I kind of do want it for looks. I mean I'll be getting separate set of track wheels with proper track tires like Toyo Proxes R888R and those for sure will be 17" plus probably they'll be much wider (since they don't need to be road legal and can poke out of car outline which is not legal in EU). I'm concerned about performance with 18" because I'm not really form over function type of guy and I'm not gonna be clown sticking 20" rims into brz. That said I'm looking for something that looks decent AND performs as good as possible with:

a) rim size that is supported so my insurance won't get cancelled due to "not officially supported rims"
b) rim that I like visually
c) rim that has all legally required certifications

Traffic laws in EU are much stricter than US so we can't just slap any wheels we like and consider it road legal.

I got reply from Subaru Import Poland and they said I can officially put tires of following sizes on such rims:

205/40R18, 215/40R18, 225/35R18, 225/40R18

So I can choose between 225/40 and 225/35 I guess... Well I think I'll go for 225/40 then since 225/35 look godawful.