How Will 50 and 55 Ratio Tires Handle?

[TeutonicShift89]

I live in the Blue Ridge mountains, so most of the best roads around here are unpaved forest roads and the like. Along with all the steep grades, pot holes, and mountains and what not, I'm looking to go with a form following function type of look with my FR-S.





I'm infatuated with the Nameless Performance FR-S and the whole rugged Rally look.


*****I'm looking to start small and experiment with putting larger tires on the stock wheels and see how I like the handling. Long term I know 16s would work better, but I'm curious what could be accomplished with 17s.


Things like 215/50/17 ---205/55/17 --- etc.


I'm looking to go with an all season performance tire like the PUHMA ECSTA PA31 since it does get cold and ice around here in winter, but I'll be doing paved twisty backroads mostly.


Anybody running these? Curious what the "do-it-all" twisty, highway, offroad experience is like on specific wheel and tire combos as far as effects on handling, ride, noise, etc. If you can confirm a certain size will rub or is too big to do this, that's helpful to me as well.


Tire recommendations would be appreciated, too.

[Leonardo]

Welcome! Congrats on the FR-S! There are only a few guys lifting their cars, so I don't know how much response you will get. Off road is also something few are hardcore into. I personally think 17 are better for tire selection; there are lots of 17's to choose from.

Having a larger side wall and taller tire will decrease acceleration (no tq) and increase top speed. Both of which are bad for driving off road. (My opinion) I run Michelin tires. Period. I like the A/S3 and the PSS. I went from the stock size 215/45 to a 225/45 on the stock wheels. The 225/45 fits well on stock wheels. I would try different tire sizes in a tire calculator to compare outside diameter to stock. this is a really helpful tool.
http://www.discounttire.com/dtcs/infoTireMath.do

the 215/50 is 0.84 taller. speedo reads = 65. actual = 67.23 this is right around The 3% +/-
the 205/55 is 1.26 taller. speedo reads = 65. actual = 68.3 This is over the suggested +/-3%

Good Luck!

[TeutonicShift89]

Thanks for the info!


Yeah, I'm not looking at "lifting" the car suspension wise. Just playing with taller tires and curious what set up is best for maintaining the road handling while gaining some cushion for off road and more clearance. I know individual tire brands' sidewall stiffness/softness plays a part in this, too.


As I saw on a winter tire thread someone was running 215/55/17 I believe and said there was rubbing at full lock, so I took that to mean that was too big.


Keep seeing folks say 215 is best for playful steering feel, but surely 225 wouldn't be too bad?

[venturaII]

For the relatively low cost of some 16" steel wheels, it seems like it'd be worth spending a few extra bucks to get the right combination of tall sidewall without changing your gearing or running into clearance/rubbing issues. A 205/55-16 would be perfect on a 16x6.5 steel wheel.

[churchx]

TeutonicShift89: if you stay NA i'd stick to 215. Of course, on gravel there is less grip, and even stock power levels are more then enough to powerslide, but if one looks on sportish tires for ice/snow rallying that are as narrow as pot covers even on very powerful sportscars, then imho on gravel it might be worth to keep narrower tires for higher pressure per square inch of contact spot, despite devil within whispering that it "seems" that wider tyres will subjectively net you more grip.
Also .. regarding rallying .. what do you think of these? (thread about them) IIRC +10mm height/more travel/different spring rates. Maybe some Cusco coilovers can also rise ride about stock. Weren't street zero-a like even upto 25mm rise front/15 - rear? Not sure it's worth using spacers to rise, as that won't change shocks travel.
+I recall seeing some Laile beatrush sump underguard skidplates (A564001R, A564001, A564001, A564002, A564004) for tripplets on ebay.
If you intend to go for bigger outer diameter tires .. mad idea, but what about that but accompanied with different final gear ratio to at least compensate it?

[Wayno]

You could go up to 195/60R16 and your speedo will be more accurate. Rally cars run around 195/65R15. Plenty of people run 225/50R16, including me.

[churchx]

I'm not thinking of just speedo accurateness (after all, it's really off even on stock wheels/primacies, if comparing to gps, but probably most manufacturers do it this way making it show some % more (is there some rule/policy/agreement to this?)). But rather worsening acceleration from bigger outer diameter of tire with limited NA power levels. - hence thought of compensating it with different final gear.

[TeutonicShift89]

@ churchx


I thought that running lower pressure in your tires in general helps grip, based on my [very limited] experience with adventure motorcycles.


What is the benefit of a higher pressure relative to tire width?


@ Wayno


I suspect that your 225/50/16s handle pretty much like stock as far as tire flexing on tarmac, etc? Minor differences perhaps but nothing more?

[churchx]

TeutonicShift89: think that grip is made not just by area, but also from pressure per area. In some cases insufficient pressure might put too wide tire in mode that's way less grippy then it's possible to get with narrower. For example - aquaplaning, where wider tire on same speed need way more pressure to push water through groves for longer distance and in bigger volumes. On snow/ice in some cases it's advantageous have less pressure/wider patch, in some - narrower to push stronger in it to stick to ground/ice beneath snow, or push deeper tire studs in it. Puddle of mud. One thing to float in porridge spinning tyres, another - have wheels touching harder ground beneath. Have not enough experience with different width tires on same car and driving on gravel roads to say what is preferred on gravel.

[Wayno]

Originally Posted by TeutonicShift89

@ churchx


I thought that running lower pressure in your tires in general helps grip, based on my [very limited] experience with adventure motorcycles.


What is the benefit of a higher pressure relative to tire width?


@ Wayno


I suspect that your 225/50/16s handle pretty much like stock as far as tire flexing on tarmac, etc? Minor differences perhaps but nothing more?

Stock 17" or stock 16"? The stock 17 are super heavy and rubbish. I swapped then out for 16" within a week.

225 are 1-2kg heavier than the 205. Less nimble, harsher. Far more grip of course because of the compound.

Everything is a trade off, can't say one setup is better than another for all occasions.

[Wayno]

Lighter tire will let the suspension work better and give more mechanical grip, wider will give more rubber grip.