Aftermarket Wheels - 17" or 16"?

[churchx]

For rally cars IIRC 15" is most common size for gravel/mud/ice/snow. As many parts of twins comes from Subaru parts bin, sometimes i wish for our brakes to better clear smaller wheels, not just one VW 15" of confirmed fitment listed in wheel directory, but something like for WRXes.
As for mentioned gazoo series wheels, i meant these. IIRC for T66-F wheels in sizing chart they also have 'gazoo' mentioned. Enkei also has 16x7 RS05 for gazoo racing. As those are cast, then of course noticeably heavier then TWS offering.
IIRC rally gt86 CS-R3 in gravel setup had OZ 15"x6 (17x7 for tarmac), but i doubt it still having stock brakes.

[Shark_Bait88]

Interesting, looks like they are using 16" for the Gazoo Series. http://toyotagazooracing.com/jp/86br...2017.html#cars

[Vracer111]

Originally Posted by venturaII

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?

For most tires it's a 2-3lb difference. A 205/45-17 tire will usually have the same tread width as a 215/45-17 tire...so same contact patch shape and size on the ground. Size of contact patch does not inidicate grip, and a larger contact patch can negatively affect wet handling depending on its shape (i.e. wider band).

Picture time, OEM 215/45-17 tires VS different 205/45-17 tires on the exact same wheels:

Originally Posted by venturaII

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

May be fine, but there is a difference between 'fine' and 'optimal' in wheel widths for a given tire size. For myself, optimal is matching tread width to wheel width for best balance in responsiveness and ride quality. A 7-7.5" wheel width lines up with the tread width of 205/45-17 tires.

Originally Posted by venturaII

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.

Combination of Recaro Sportster CS seat that ties you into the chassis like a racing seat so you can really precisely feel what the car is doing (not flopping around like in stock seat and getting a more vague interpretation), the reduction in tire diameter netting a near .2" CoG drop, and changes in track width really gave very different feel between the two setups. The 205/45-17 DW setup is more playful on the street, yet more precise in movement and absolutely planted in hard cornering, much more so than the 215/45-17 XS setup. The 215/45-17 XS setup had overall higher grip level (dry only, wet is nothing comoared to the DW's, which are one of the best wet tires made) but was also more skittish and upset at the limits. A wider wheel with wider track is not what I consider an improvement because what I value and want out of the FR-S is honing the reflexes and making it more transitionally responsive/light on its feet while also improving ride quality. A wider/heavier wheel/tire setup does not align with those goals.

Originally Posted by venturaII

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.

Smoother ride and less weight because of specific tire chosen... and zero mechanical grip is given up because, as always, tire compound determines grip not tire width. I chose the tire size first and then based the wheel size off it. 205/45-17 makes the most sense to me for a daily driver that I wanted to enhance ride yet increase its quickness - stock contact patch shape/area, slightly smaller diameter (for better respinsiveness and lower CoG), and large selection of Max Performance category tires that aren't too expensive. I did look into 16" tires, even have an old set of 16X7+42 Enkei RS5's with 225/45-16 Hankook RS2 that I ran on my Tacoma that I tried on my FR-S for a lityle while. Besides the RS2 having zero grip from being so old, DIDN'T like the ride quality with them. Was thinking of trying to find lighter 16" tires sizes but options are severely limited and sometimes more expensive than the 17"s. And then I thought about future brake upgrades - 16" wheels will be a much more difficult fitment with an upgrade front brake system. So 17's it is for me, 16's will be a lot more difficult to be made to work.

Have you driven on 205/45-17 Continental ExtremeContact DW's mounted on lightweight 17x7.5 +40mm offset wheels with stock suspension to be able to say it's not an incredibly dynamic ride? Much more dynamic than the stock wheel/tire configuation...stock is 2 dimensional one-trick pony handling in comparison.

[ZDan]

Originally Posted by Vracer111

For most tires it's a 2-3lb difference.

Are you still comparing a 225 16" vs. a 205 17"? WHY?
Compare 225/50-16 vs. 225/45-17, and compare 205/45-17 vs. 205/50-16, and 205/50-17 vs. 205/55-16.
Similar width/diameter 16" tires weigh about the same as 17". Sometimes the 17" is 1 lb. heavier, sometimes it's 1 lb. lighter.

A 205/45-17 tire will usually have the same tread width as a 215/45-17 tire...

I pulled up three tires in these sizes and lo, 215 tread is wider for all 3:
Conti ExtremeContact Sport 205 = 7", 215 = 7.3"
Bridgestone RE71R 205 = 7", 215 = 7.2"
Dunlop ZII StarSpec 205 = 7.6", 215 = 8"

I do agree that width isn't everything. But a wider wheel/wider tire/wider contact patch will give greater lateral grip in general. But it's not as huge a difference as most people think... But a wider/shorter contact patch doesn't deform as much under hard lateral load and doesn't overload the outside edge as much vs. narrower/longer contact patch. On the street, though, IMO there's little to nothing to it...

205/45-17 makes the most sense to me for a daily driver that I wanted to enhance ride yet increase its quickness

Was thinking of trying to find lighter 16" tires sizes but options are severely limited and sometimes more expensive than the 17"s.

For 16s, you pretty much get all the important Extreme Performance tires, but a lower percentage of the Max Performance tires. 16s pretty much always cheaper for same make/model of tires...

Personally, I like to stick with the smallest diameter wheels I can and still run the tire widths I want and fit over brakes. I've never needed to upgrade the s2000's brakes so I went with wider 16s for my track wheels instead of going to 17s.

For sure there are many options, so to each his/her own, I say...

[scottbrz]

I had considered the very same thing for when the OEM tires on my BRZ are finally worn out. That would present an opportunity for a wheel upgrade.

I really like the OEM 16 inch wheels from overseas, but here in the states they seem to be unobtainium. And the minimalist in me really likes the idea of 16s on this car.

But after careful consideration and research, I concluded I'd stick with 17s due to:

* Tire selection seems to be better in 17 inch sizes
* While 16 inch wheels tend to be lighter, to achieve the same overall diameter you need more tire, which tends to weigh more; this of course varies and you can find tires that do not sacrifice on this front, but some research on tirerack seems to indicate a trend of the 16 inch size of a given tire is 1-2 lbs heavier than equivalent 17 inch sizes; this seemed to be true at least in the stockish sizes I was interested in; this nullifies most or all of the 16 inch weight advantage for reasonably priced wheels
* You are potentially locking yourself out of BBK upgrades later (many of which can save a surprising amount of weight)

When the time comes, I'll likely go with the el cheapo motegi traklite mr131 in 17x7 if they are still available and there are no better alternatives. They have a very agreeable price point, close to stock offset, around 17 lbs, and have a very clean classic five spoke design.

I'd love some rpf1s, but those motegis are so much nicer to my wallet.

[ZDan]

Originally Posted by scottbrz

* Tire selection seems to be better in 17 inch sizes

Best Extreme Perf tires available in 16", tho...

* While 16 inch wheels tend to be lighter, to achieve the same overall diameter you need more tire, which tends to weigh more; this of course varies and you can find tires that do not sacrifice on this front, but some research on tirerack seems to indicate a trend of the 16 inch size of a given tire is 1-2 lbs heavier than equivalent 17 inch sizes; this seemed to be true at least in the stockish sizes I was interested in;

I'm just not seeing it. For same/similar/close-as-possible width and diameter, 17" and 16" tire weights are pretty equal, at least for the tires I would be considering:
RE71R:
205/45-17: 21 lb
205/50-16: 21 lb

225/45-17: 23 lb
225/50-16: 23 lb

ZII StarSpec
205/45-17: 20 lb
205/50-16: 21 lb (+1 lb)

225/45-17: 25 lb
225/50-16: 24 lb (- 1 lb)

Hankook RS4
225/45-17: 24 lb
225/50-16: 25 lb (+1 lb)

Toyo R1R
225/45-17: 23 lb
225/50-16: 23 lb

Yok AD08R
205/50-17: 22 lb
205/55-16: 21 lb (-1 lb)

225/45-17: 24 lb
225/50-16: 23 lb (-1 lb)

[Vracer111]

For any tire purchase (for the FR-S or a performance car) I will not really consider any that has a larger diameter than the stock specification, only stock diameter or smaller - within reason (trucks would be different because I would actually want taller tire for offroad clearance reasons). Reason is two-fold; first I rather the speedometer error show me going faster than actual speed rather than slower than actual speed, and second, is it automatically comes with a minor CG drop and less rotational inertia/more responsiveness. 16" tires mostly are either slightly too large or WAY too small, The 205/50-16 is probably the size I would choose though it's kind of getting close to being too small a diameter, but I'd have to drop down from Max performance category to Ultra High performance category, which is second best for wet performance (Max being first). There are ZERO Max Performance tires in that size. They are also heavier than 205/45-17 size. Nice prices though.

Yes, I miss-spoke on the 215 and 205 widths being the same, thought for sure they were within .1 inch of each other from the last two times I've purchased tires. I know the tread on the 205/45-17 Kumho Sport LE's is .2" wider than the stock Michelins.

I don't want Extreme Performance category for a road car, Max Performance are a better daily tire because of their wet performance. I live in a subtropical coastal climate region, heat showers/downpours are a thing in the summer time. Continental ExtremeContact DW is a near perfect daily tire, wet performance is right up there with the dry...meaning you can drive in the wet like you can in the dry...incredible wet performance for a decent price, along with being one of the lightest tires you can get.

My plan is to upgrade the brakes to ESSEX upcoming Radi-CAL based kit, which is probably going to have slightly larger diameter rotors than the Sprint Kit. Will keep with 17x7.5 +40mm to +42mm wheel size for track and use 205/45-17 Direzza ZII tires most likely unless can find a DOT-R in that size (like say a Nitto NT01 that I have had good experience with on other vehicles) but they don't seem to exist.

Wheels and tires are indeed a personal preference and like so many things in life, there is often more than one solution to a problem... everyone has a way to solve issues.

[churchx]

Vracer111: speedo error importance is overrated. After all, on reasonably new cars (IIRC by manufacturer agreement) it lies even with stock sized wheels/tires (around 8% on mine vs gps, more then advised to keep within 3% wheel/tire circumference changes), so fitting larger wheels will only get speedo to lie less .
Though i'd also would keep overall wheel+tires circumference close, like you, but for reasons to not worsen acceleration too much, due taller overall gearing ratio change.
P.S.
regarding truck wheel size/ground clearance ratio .. there is also option of using same wheel/tire size but with lift spacers.

[venturaII]

Originally Posted by churchx

Though i'd also would keep overall wheel+tires circumference close, like you, but for reasons to not worsen acceleration too much, due taller overall gearing ratio change.
.

Remember - the difference between a 24.7" tire and a 25" tire is barely 1%. You are NOT going to feel that.

[ZDan]

Originally Posted by Vracer111

For any tire purchase (for the FR-S or a performance car) I will not really consider any that has a larger diameter than the stock specification, only stock diameter or smaller - within reason

IMO, odd thing to be so specifically fixated on. Small differences +/- are going to be undetectable.

The 205/50-16 is probably the size I would choose though it's kind of getting close to being too small a diameter, but I'd have to drop down from Max performance category to Ultra High performance category, which is second best for wet performance (Max being first).

In my experience, Extreme Performance tires don't give anything at all away to Max Perf tires in wet grip. They will generally hydroplane sooner in standing water, but driving reasonably in torrential downpours and replacing before getting to the treadwear indicators, I've never had any issues.

There are ZERO Max Performance tires in that size. They are also heavier than 205/45-17 size. Nice prices though.

UHP tires, 16" vs. 17" weights (not cherry-picked, just selected the tires I would consider in this category that come in both these sizes):
Firehawk Indy 500
205/45-17: 20 lb
205/50-16: 21 lb (+1 lb)

Yok S.Drive
205/45-17: 22 lb
205/50-16: 22 lb

B'stone RE760 Sport
205/45-17: 22 lb
205/50-16: 21 lb (-1 lb)

BFG G-Force Sport Comp-2
205/45-17: 21 lb
205/50-16: 22 lb (+1 lb)

[edit]For completeness I'll add in the other two that appear when selecting both 205/45-17 and 205/50-16 tires in UHP Summer category at Tire Rack:
Riken Raptor ZR
205/45-17: 23 lb
205/50-16: 22 lb (-1 lb)

Kumho Ecsta PS31
205/45-17: 20 lb
205/50-16: 20 lb

I don't want Extreme Performance category for a road car,

I *used* to run Max Perf tires on the street, but I've found that I would miss the responsiveness and trackworthiness of Extreme Perf tires.

I wouldn't go strictly by performance category to judge wet grip, for sure there are some in the Max category that suck in the wet. Most good Extreme Perf tires have fantastic wet grip. And the reduced hydroplaning resistance is not an issue for me, and I DD on Extreme Perfs in torrential rains as well.

Will keep with 17x7.5 +40mm to +42mm wheel size for track and use 205/45-17 Direzza ZII tires most likely unless can find a DOT-R in that size (like say a Nitto NT01 that I have had good experience with on other vehicles) but they don't seem to exist.

As I went from Max Perf to Extreme Perf on my DD S2000, I also went from Extreme Perf to DOT-R as "street" tires for my FD. NT01s do make great street tires! Again, wet grip is actually good, but drastically reduced water-channeling for standing water...

Wheels and tires are indeed a personal preference and like so many things in life, there is often more than one solution to a problem... everyone has a way to solve issues.

Agreed!

[churchx]

DOT-R as "street"? With their wear rate isn't it getting a bit on expensive side, if driving normal daily driving distances? Also will they grip well if you won't get heat in them (if driving within legal limits)?

[James Russels]

Wow, did not expect this to get so much attention! I really appreciate all the input from everyone. Due to time constraints, I can't reply to all comments, but I think I've settled on 17" diameter. I'm now trying to figure out wheel/tire width. Because I want to go FI eventually, I found that 245mm seems to be the lower limit of tire width people recommend for that application.

Originally Posted by Shark_Bait88

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

Mainly street driving, but I have considered trying autox. It's not a strong enough consideration to be a significant factor in my decision, however.

Originally Posted by Shark_Bait88

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.

What would be the problem, if any, with going 17x8 with 245s? 8" wheel width is the low limit of what the 245mm width tires I'm looking at require.

Originally Posted by scottbrz

I had considered the very same thing for when the OEM tires on my BRZ are finally worn out. That would present an opportunity for a wheel upgrade.

That is exactly what I am doing haha. OEM tires were at 3/32" last oil change (in January) so the clock is definitely ticking...

[James Russels]

Also:

Originally Posted by scottbrz

When the time comes, I'll likely go with the el cheapo motegi traklite mr131 in 17x7 if they are still available and there are no better alternatives. They have a very agreeable price point, close to stock offset, around 17 lbs, and have a very clean classic five spoke design.

I'd love some rpf1s, but those motegis are so much nicer to my wallet.

I was actually considering those earlier - I love how they look. The price is definitely an advantage over the RPF1s haha.

[nikitopo]

Originally Posted by churchx

As for mentioned gazoo series wheels, i meant these. IIRC for T66-F wheels in sizing chart they also have 'gazoo' mentioned. Enkei also has 16x7 RS05 for gazoo racing. As those are cast, then of course noticeably heavier then TWS offering.

The Enkei wheels have a good price. In fact they are a bit cheaper than 2 years ago and Subaru won a few races with them. TWS exactly double the price?