Aftermarket Wheels - 17" or 16"?
 

Hi everyone,

I am looking to get some aftermarket wheels for my stock 2013 FRS. I have done quite a bit of research and need some guidance to reach a decision. To start, let me outline what I am trying to achieve with the new wheels:

-Improve stock handling via grippier tires and reduction of unsprung mass

-Improve acceleration via reduction of weight and rotational inertia of wheels

Potentially relevant future plans for the car – I would like to turbo it and lower it by about 1-1.5”.

I am strongly considering 16” wheels for the weight/rotational inertia reduction. The wheels I’ve selected are the Enkei RPF1s (16”x7”, 35mm offset). However, I have found the following potential issues with doing this:

-Very limited tire selection – all I have been able to find are the Dunlop Direzza DZ102s and Kumho Ecsta ASXs. On Tire Rack, the Dunlops have a 4/5 rating and the Kumhos have a 3.5/5. Not sure how indicative that is of their actual quality, but it is something I have been considering.

- The offset of these wheels is 35mm as opposed to the 48mm stock offset. I should note that the 17” diameter version of these wheels have a 42mm offset (anyone know why this may be?). I DO like the look of lower offset wheels, however, maintaining stock feel takes precedence. Based on what I have read from other people who went with significantly lower than stock offset (at least 10mm difference), the change in handling was noticeable. I also want to avoid putting excess stress on the suspension.

-Smaller wheel = higher tire sidewalls = worse handling. However from what I was able to find during my research, it seemed that the 1” smaller diameter had a negligible impact on handling. I would appreciate if anyone could confirm or refute this.

Based on all this information, I am curious to hear cases both for and against 16” wheels, as well as any possible ramifications resulting from having the lower offset on the 16” wheels. In addition, information about any corrections that could be made to the suspension to account for the lower offset would be appreciated (to my knowledge, greater positive camber would “correct” this, at the expensive of more uneven tire wear and different handling characteristics).

For anyone who made it through this whole post, thanks for reading and I appreciate any help.

TL;DR – Want to upgrade wheels, not sure if 16” or 17” is the right choice.

I'm currently running Motegi Forged Tracklites in 16x7 +40 - very light - and well worn Kumho Ecsta XS in 225/50 -16. I have a set of RT615K+ in the basement as well, waiting to get put on. I personally think the 16" wheel looks better than the 17s on stock height suspension, and the 12.5 lb weight of the wheels is definitely noticeable. Not night and day transformation of the car, overall, but enough to make the suspension feel more nimble and quick to respond..it's nicer to drive. And even with a tire with a MUCH stiffer sidewall than the OEM Bridgestones, the ride quality from the taller profile is also a nice bonus, given the deplorable road conditions around here.

In theory, the slightly taller profile will lose a little steering response, but the tire brand/model you choose has FAR more influence on that than the simple numbers. I've lost no steering response compared to the stock setup, that I can notice. Additionally, the right alignment can offset any theoretical slower response.

If I had a choice, I'd probably have a 7.5 wide rim for a 225/50, but the tire's specs are taken when mounted to a 7" rim, so I don't think I'm giving much up. Keep searching for 225/50...there are a few options out there...certainly not like with 17s, but there are a working selection.

Once my Tracklites are eventually/inevitably damaged somehow, I'll probably be replacing them with the heavier, but still available and affordable RPF1s in the same size you mention above. There are lighter wheels than the Enkeis in that size, but they start getting ridiculously expensive very quickly.

There is your answer.

What size are you looking for? TireRack has 62 hits for 225/50-16...

https://www.tirerack.com/tires/TireS...earDiameter=17

A 225/50-16 tire is ~3lbs heavier than a 205/45-17 size tire (which is the most appropriate size for a 7"-7.5" width 17" wheel) and is .3" larger in diameter than stock spec. A 205/45-17 tire is .3" smaller in diameter than stock. Any given model of wheel in 16x7 verses same model in 17x7 size is usually within a 1lb to 2lb difference... so that 16" setup is overall heavier and larger in diameter than a 17" option that makes the car a much sharper and quicker scalpel. The main issues in 16" tires for an FR-S is proper sizes, they are either a little taller (205/55-16 or 225/50-16), or WAY too short (everything else) ... there is no little shorter selection available.

Advantage goes to a proper matched lightweight 17" wheel/tire combo...

There is only ~1lb difference between a 16x7+35mm and 17x7+42mm RPF1. Tires however are a 2-3lb difference in favor of 17". Not to mention all 2 most suitable 16" sizes are a taller tire. So you have more weight, further out...tires have more impact on handling than wheels. I'd highly recommend 205/45-17 Continental ExtremeContact Sport tires on lightweight 17x7 or 17x7.5 wheels if you want your FR-S to be more agile and responsive daily driver that also rides great and yet is more stable and planted at the same time due to free CoG drop from .3 shorter diameter and light weight tires. If you could swing it (over double cost of RPF1's), BBS RF forged in 17x7.5"+48mm weigh ~14lbs and look gorgeous. BBS RF's + ExtremeContact Sports is a wheel/tire combo that would come in ~ 33lbs...

I'm on 17x7.5+40mm Enkei Fujin wheels (17lbs) and 205/45-17 Continental ExtremeContact DW's (19lbs) and would never go back to a bigger/wider wheel setup. Had 17x8+36mm Kosei K4R (15.6lb) and 215/45-17 Kumho Ecsta XS (21lbs) before... and it was just not as good or as fun to drive on.

Why not compare like vs. like? 205/50-16 RE71R tire is the same weight as a 205/45-17 and is only another 0.2" shorter.

Personally I'd probably go 16x7.5 or 16x8 and run 225/50-16s. Like-width vs. like-width: 225/50-16 is 0.2" taller than OEM, 225/45-17 is 0.3" taller, and they are the same weight.

So if you wanna run 225s, 16s do not have any weight or height penalty vs. 17s.

There's a great selection of extreme perf tires in 205/55-16 and 225/50-16, which are usually only 0.2" taller than OEM. Options in 205/50-16 and 225/45-16 are very limited, but still the best performance street tires available (RE71R, ZII StarSpec)

On 16x7" wheel, I'd run 205, but again I'd probably go 16x7.5 or preferably 16x8" and run 225s.

That's a pretty general statement, and will vary from tire to tire, depending on make/model. For example, the difference between an RT615K+ in 225/50-16 and 215/45-17 is just one pound. A 205/45-17 doesn't even exist in that model. The bigger question is: why would you want less rubber on the ground rather than more?







Totally untrue. A 205/45 is fine on any rim width between 6.5 and 7.5 inches.







So you're saying the difference between the two setups was the measly .6lb, and that you're actually able to feel it? I respectfully call BS on that, and suggest instead the difference is almost entirely in tire brand and model itself. We won't even bring up that you've gone from a wider grippier tire to a narrower, less sticky one... And the .3 difference in height is barely 1% different...again, I'm calling BS on this being a detectable change under the most rigid testing conditions, let alone from the driver's seat.






Why you'd want to go to a shorter, narrower overall tire is beyond me. Besides looking terrible (just my personal opinion), you're giving up mechanical grip and losing sidewall, which is one of the appealing factors in going to 16s. The car becomes a much more dynamic and involving ride with 16s, especially when on stock or close to stock suspension.

Weren't AD08R also available in R16 sizes? MPSS IIRC not, but MPS4 might be.

Generally you can get all or most of the good Extreme Performance tires in 16", but not Max Performance tires. Screw Michelin anyway, MPSS tires on my FD were initially OK but turned to garbage in less than two years, with half tread depth still remaining. Haven't experienced such a radical loss in grip in a street tire ever before, except a set of B'stone S03s I heat-cycled to death at the track.

Do you mainly street drive the car, or will you be doing any autox/track events?

Personally, I'd go for 17x8 or 17x9 RPF1s. 17x8 with 225s seem to be the sweet spot for NA track cars according to many people, or 17x9 with 245s or 255s for higher power boosted cars and STX classed autox cars.

17" RPF1s in either width will still be significantly lighter than the stock wheels. I probably wouldn't go to 16s for better performance, because of the negative effect on handling that a taller sidewall can create, as you noted. There are also quite a few other quality lightweight wheel options in the 17x7-17x9 range. The newer TRD wheels are 17x7.5 and forged, that weigh around 17lbs I believe. Not the lightest things out there, but a brand new set of forged wheels for ~$1,400 is a pretty solid deal.

I'd say that said negative effect is arguable. Yes, turnin might be less sharp due more sidewall flex, but not by much with modern tires with stiff sidewall. Also some may prefer more comfort, cheaper price they get in return, if used on daily rides, and some may prefer more mass transfer on track. Weren't gazoo racing series wheels 16x7 TWS-F66? Weren't trend in real sport to get smallest possible wheels, that still clear brakes?

Fair enough. Not sure on the TWS-66F on the Gazoo car. All of the pictures of their car that I can see, and can remember, have it on 17s. Couldn't even find any pics with the TWS-66Fs, but of course I could just be missing it.

Pretty much every other professionally raced 86 I've seen though, including all the TMG Cup cars, have 17s. With rally cars being the one exception, although many still look to use 17s for tarmac courses.