Question on Tire Size for Stock Rims
 

Hey everyone, im looking into getting a new set of tires for the stock 17’ rims that have 215s on right now. I want something beefier so the rear wheels are almost flush and for a little better cornering. Any suggestions?
For instance 225s on all four corners, or are 245s possible?

I put 225 PS4S's on my stock 7" rims and like the results. The understeer was gone and it tracked very well on corners. The ride was also slightly improved over the stock 215 Primacies. There is a slight difference, however, in the speedo as at 60 mph you are actually going about 61 mph. I can live with that. Those rims are too narrow for a good fit with 245's. In addition, putting on 245's will not give you any better performance. The big difference is the quality of the tire. The PS4S is a much better performance tire. I chose the 225 over the 215 because the PS4S tends to have a slightly narrower tread width than the Primacies. Given the fit of the 225's on my rims, I certainly would not go wider.

Yes, 225/45 will work, and as a stop-gap solution, it is not bad. But if you want wider tires, you need wider wheels to be optimal.

I just got 215s for my 8" wheels. Because, IMO the wheel was not wide enough for the 225s I had.

Tire manufacturers have specs for rim width for particular tires. Michelin says you can SAFELY install their 225 PS4S tires on 7-8.5 inch rims. In fact, their specs are based on installing 225's on 7.5 inch rims which is the optimal rim size in their opinion. Installing these 225's on 8" rims is not even questionable so I don't understand where you would get such an idea. Wider wheels/tires deliver virtually no performance benefit over 225's and in most cases are solely installed because owners like the way they look.

Ok. Cool.

OP asked about sizes, I gave my opinion based on using different tires on different wheels on my FR-S. I have read the manufactures suggested range.

OP a 225/45 is not going to flush out the wheel because it has a +48 offset. Spaceres will; with the stock wheels and tires. +15 to +25 front and +20 to +30 rear is what guys are running on stocks.

OP has 17x7 wheels, so your information was incorrect. Flush is in the eye of the beholder. IMO, spacers on the fronts make the wheels poke a bit. Same is true for 20mm spacers on back. Assumption that a wider track in this car improves handling is just plain wrong. 225's will give him a slightly beefier look without spacers. Spacers may also require a camber adjustment which he may also not know.

You should also have 17x7 wheels, so if you did read the manufacturer's range, you'd know.... Perhaps you can show me the spec sheet you referenced for 225's and 7 inch rims.... I'm always open to learning something....

:sigh: I never talked about assumptions; You assumed that I think spacers are a performance mod. You are incorrect.

They just flush the wheels out. And if your opinion is that it makes them poke, thats totally cool. But many forum members do not feel that a 225/45 flushes out the stock wheel, and thats why they run spacers.


I have had over 60 tires on my FRS already, and my opinion is that a 17x7 is not wide enough to optimally run a 225/45. And since OP mentioned 245s, I know he is thinking about them, so my suggestion to get wider wheels if he wants wider tires than 225 is correct.

My signature, has my current 18" wheels. They weigh less than stock.

You said you had the manufacturer specs -- I guess you don't. Have you ever run 225/45R17's on your FRS? I have them on my BRZ and it's not even a close close call as there is absolutely no pinch. The OP indicated he thought the spacers would make the car corner better, so it was referenced as a performance mod. And for the record, I have no problem with you modding your car in any way as it is your money. IMO, wide 18's with 245's on a 40mm or so offset makes the car look good. But if you are really after performance, 17's are probably better and wider tires are not except in special situations. I have done a lot with my cars on the basis of how they look, so I certainly have no criticism if you wish to do that. I tried to justify getting new rims on my 2018 instead of just new tires, but I couldn't do it on the basis of performance, so I decided not to do it. It was awfully tempting to look at all of the wheel options out there. In my younger years, I did a lot of things like lowering, headers, exhaust, intakes, wheels/tires, hot cams, etc. But at my old age, I'm only willing to mod if there is a significant performance improvement I need in a daily driver. The only one I could justify on that basis was the upgrade to the PS4S's. Lowering the car an inch or so makes it look better, but it does degrade the ride quality and doesn't make the car handle better.

I'm just trying to give the OP an objective answer and not trying, in any way, to degrade what you have done. For us car freaks, our cars are an extension of us. So if it makes you feel good to do any of this, you should do it....

I stated that I read the manufacturer specs. And, yes I have had 225/45 on stock wheels and on 17x7.5 wheels. They fit better on a wider wheel than 7".

You mention in another thread that Michelin was wrong about the factory specs. So you already understand that they can be incorrect. I've stated my opinion about Tire width and rim width. You've added a whole bunch of other stuff in with your assumptions. I understand you want to give OP all the information so he can make an educated choice on what tire and wheel he adds to his car. Thats Great! And some guys run 17x9 with 245, even though YOU think it does not increase performance.

Additionally, IMO, you decided to not get rims on a basis of budget. NO race team uses stock wheels. So obviously, there are better wheels than stock performance wise.


Good luck!



This has been a fun back and forth, I hope you don't feel personally attacked. Everyone is entitled to their opinion, and I have been posting mine here in the wheels/tires section for almost 6 years. Thanks for sharing yours.

Check out my build thread for more info.:thumbsup:

When a manufacturer like Michelin gives a range of wheel widths, I've found that the fit is just fine on their range. Within that range, I'd agree that 7.5 for 225's is a "perfect" fit, but I wouldn't go with less width just because I had a 7" rim. And I wouldn't say to anyone that you shouldn't put 225's on a 7" rim. I can tell you from experience, the fit on a 7" rim is extremely good.

Just because someone runs with 10.5" width rims and 265's doesn't mean it's the best performing setup. In fact, there is a lot of evidence that putting anything wider than 225's on the front reduces handling. Extra wide wheels and tires also weigh a lot more. If there were evidence that putting 245's on this car improved performance for a street daily driver, I'd get new wheels and tires in a snap.

While there may be some errors in the Michelin specs, I've found them to be far and few between. And when there is an error, it is a large one like the weight of the 225/45/17 PS4S. That error is really obvious. Over the years, I've never found an error in rim width and I've purchased hundreds of Michelin tires....

Pretty much end of thread with that answer. With the stock wheels, spacers are the only way getting "flush".

To OP: The spacers on stock wheels thread in here http://www.ft86club.com/forums/showthread.php?t=59838 is what you seek.
Also bunch more here:https://www.google.com/search?q=spac...w=1920&bih=949

So to get this straight and settle it. I have been looking at getting 225s on the front and 245s on the rear with these exact tires and stock rims. Looking at the feedback that wont work and or wont fit? (I know some people will roast me for looking at Firestones but I have had a set previously and the reviews are also very good compared to others) --> https://www.tirerack.com/tires/tires...I5XL&tab=Sizes

Yes that will fit no problem, but putting staggered tires on this car isnt ideal from what I've read around here. I have no experience with staggered setup on this car so i cant say much. No one is going to roast for those tires those are very well acclaimed tires and people will praise you for getting them.

I just know in the car community firestones aren't looked upon too highly. From what other responders have said 245s on all four corners isn't the best idea. This may be a dumb question as im not super knowledgeable on tires, but wouldn't 245s on all four corners be better than 225s from a performance perspective as long as everything fits just fine?

If you are looking for flush, wider tires are not the solution. You need either wheels with more offset, or run spacers on your stock wheels.

The Indy 500 are an awesome tire in fact i plan to get those as well. People say not to get 245/40 because its just a lot of tire for this car's power. If you wanted to run 245/40 you can just get a 17x9 wheel for best fit. People have also put 245/40 on a 17x8 wheel and theres mixed reviews on that.

As for a wider tires being best for performance theres been a lot of debate on that you can reference this thread https://www.ft86club.com/forums/showthread.php?t=126829

I think I will wait until my stock tires have a little more miles on them (17,000) and then upgrade to some indy 500s. For the flush look in the rear, these look like they will do the trick. Any input? https://www.amazon.com/Hubcentric-Sp...+wheel+spacers

That will depend on what wheels you choose and what offset those wheels come in. If you just want to make your stock wheels flush you need a 20mm spacer front and 25mm spacer in rear. But since you have an RS1.0 you already lowered an inch from factory so when you buy new wheels get a lower offset and you should be just about flush.

Yeah those would work but you should go ahead and do both ends. @Leonardo gave you good specs on what to run in his second post. The front doesn't need to be pushed out as much as the rear.

Awesome, thanks for the help everyone. Until I need new rubber I’ll probably just get some hubcentric 20mm for the front and 25mm for the rear :cheers:

225/45 is max size for the stock wheels IMO. A 245/40 will be pinched on a 17x7". I ran 245/40 MPSS on a 7.5" wheels; they were pinched a bit. Not ideal at all.

Spacers do not negativly change the ride for DD. Getting 225/45s and spacers would most likely make you happy.

Cant say Ive tried firestones, specifically those ones anyway. But I can say that I jut got Hankook evo v12 tires to replace the expensive Michelins I was running. Terrible choice. I had burnt through 20 MPSS tires and thought that "Maybe I should try something else and save a few bucks" Bad idea. The Michelins are way better, and totally worth the money. I will be swapping back soon, though I am probably going to try a newer model Michelin.

Finally... my point: Firestones are inexpensive; the savings may not be worth it.


:cheers:

I have to strongly disagree on Firestones not being worth it due to the low price. They are better in every way than the MPSS I had on previously by leaps and bounds.
I've already said it in here but will repeat that if the Indy 500s cost more than the MPSS, I'd still buy them and MPSS are way overpriced because of their reputation.
Leonardo said he went through 5 sets of them. That leads me to the main negative of the MPSS. I barely put 8k on mine before they were fully dead and the previous owner may have had them
for a little more but they wear way too fast. The Indy 500s have 4k on them and look like they are still new. Second negative was sliding around and even losing control
and spinning on the MPSS making a u-turn made me scratch me head wondering how those tires get such a good rep. Only positive was people seen they were on the car and said "good choice of tire".
At almost double the price of the Indy 500, I just laugh that anybody would have spent that on the outgoing Super Sports and especially now that the Pilot Sport 4s is indeed more than double of the Indy 500s.

To Leonardo, since you're going through so many tires and/or not happy with what your on, maybe give the Firestones a try next time and see what happens.

As far as I know the Indy Firehawks are just rebranded Potenza RE003's.
They're definitely better than the PSS or PS4s in terms of outright dry grip.

Any reference to Firestone of the past (blow out and SUV rollovers) probably do not belong in a discussion about the Firehawks.

Interesting. I Really HATE the soft sidewall of the Hankook V12's. I am going to change them. Thanks for the input.

We can argue about 225s on the stock rim. It is within spec but personal opinions differ. I did that and it was fine for me. However, there is no argument that 245 is out-of-spec on the stock 7" rims. 245 width requires minimum 8" rims. That is what I have right now.

245's on four corners are just fine if you need the extra grip for increased power or track racing purposes. For daily driving on the stock power level, they are just for looks with a performance penalty. Looks is a good excuse though :)

Could you elaborate on this "performance penalty"? I am looking at getting 245/40/17 tires, but still undecided whether to go 245/40 or 225/45. Just trying to get different opinions.

Vital: more sideways grip which isn't used at DD, but less acceleration due weight/more rolling resistance.

While giving more grip at the corners, in acceleration, and stopping power, wider tires are generally heavier and higher rolling resistance against the motion. You could have lower mpg and top speed. We are talking about a few percentages difference but you might feel the drag of wider tire depending on your power level.

225/45 also has another imho not the least important good bit if one wants to save a bit (especially if one tracks the car and goes through several tire sets per season). Simply said, it's one of most common tire sizes, and 225/45/R17 tires often are noticeably cheaper then other tire sizes (not just vs wider/lower profile ones, but including stock 215/45/R17 btw). Another bonus - narrower the tire, less it's susceptible to aquaplaning.
Unless one auto-x car and wants most grip for slow speed turns/transitions within some class limits, unless it's for questionable wide tire looks, for performance & budget reasons imho 225/45 is tire size to go for if for NA twin for both DD & HPDE.
I'd go wider 'for performance reasons' only if car has forced induction, where increased weight & rolling resistance penalty matters less then if for stock NA power.

Quick Update
 

Installed 3 new mods on my banana this weekend

- 20/25mm spacer setup (wow I can feel the difference cornering and of course it looks more aggressive)

- A backup camera

- TRD black fill in decal

In time I still plan on getting a set of 225's all around :thumbsup:

For DD I would stay 215 and keep the car playful and light. Why put on heavier tires for DD. I have way more grip with my WRX in the corners with 225, but the BRZ is more fun for some reason. If you need more grip for autox or track then 225 is the way to go.