16 inch wheels - 45 or 50 ratio?

[CJ416]

Autocross season is coming up fast as we all know, and I'll be buying indy 500 tires and 16" wheels (most likely dekkagrams) for the warm weather. I've noticed a pretty even split between 205/45 and 205/50 and have a few questions about the difference in size

Fitment - I've never seen any issues with rubbing with a 45 aspect ratio, is it a problem when moving up to 50? I love a good meaty tire, but would like to avoid fender modification to prevent rubbing

Comfort - the FiST's Achilles heel as a daily is its ride quality, and moving down a wheel size is a big help in improving this, I'm just wondering if you can really tell the difference with a 205/45/16, and if there is a dramatic improvement in comfort with a 205/50.

Wheel gaps - how does a 205/50 look on stock suspension? I know with a 205/45 the wheel gap is a bit more apparent, and looks much better with lower springs, so I would be buying eibach springs along 205/45, but I assume the taller sidewall of a 205/50 would have a less apparent wheel gap

Sorry for the long winded post, and possibly obvious questions, I'm just making sure I have as much information as possible to make an informed decision

 

[M-Sport fan]

Since I just bought the Dekagrams for a daily driven 'intermediate weather' type wheel/tire setup (to replace the stockers with the Pilot Sport AS/3s on them), I am opting for some 205/50s in an XL load rated, UHP all season.

I CANNOT use a 300/340 tread wear actual summer tire, let alone a 100/200 tread wear gumball, in the temps this setup will see as it will DESTROY THEM (freeze them solid, crystallize the compounds, and render them useless IF it does not crack their tread first ).

The reason for a 50 series over a 45 is simple, the winter/spring condition roads around here EAT rubber band profile tires (AND the wheels they are mounted on) for breakfast, lunch AND dinner, and it is not even fully 'crater season' yet!!

There is ONE 215/45-16 decent brand (Vredestein) all season available which I have just found out about today, and it might be the ONLY 45 series I would even consider since the sidewall is higher than a 205/45-16.

IF these ever become my summer wheels (dependent on the sale of my 17x8 1.2s with 215/40-17 RS-RRs on them), they WILL get a 100 or 200 tread wear sticky in a 215/45-16 or 225/45-16 size.

BTW; I actually LIKE the way my car sits with the very tall 195/60-15 winter/rally working setup on it at FACTORY ride height level, as it fully fills the wheel wells, and does not rub anywhere.
The 205/50-16 is right about the same height as these (maybe .2" shorter), so I expect it to look as good, or better.

 

[HBEcoBeaST]

Running dekagrams on 205/50 Indy's. Worn out stock suspension. I've rubbed a couple times but only at speed around a turn with a big dip/bump. Never rubbed doing cone events or normal/spirited driving, full lock etc. Only rally style stuff. I have bilstein coilovers awaiting install and I plan on going lower .25-.5" and am not concerned with rubbing.

With the slight stretch and higher weight rating, I'd say the 205/50s have stiffer sidewalls than 205/45s. Slightly more comfortable than stock but not night/day. I am less afraid of potholes though. I don't poke at all. Steering was slightly affected but my chassis bracing and motor mount upgrades make my car sharper than OEM anyways.

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[CJ416]

Running dekagrams on 205/50 Indy's. Worn out stock suspension. I've rubbed a couple times but only at speed around a turn with a big dip/bump. Never rubbed doing cone events or normal/spirited driving, full lock etc. Only rally style stuff. I have bilstein coilovers awaiting install and I plan on going lower .25-.5" and am not concerned with rubbing.

With the slight stretch and higher weight rating, I'd say the 205/50s have stiffer sidewalls than 205/45s. Slightly more comfortable than stock but not night/day. I am less afraid of potholes though. I don't poke at all. Steering was slightly affected but my chassis bracing and motor mount upgrades make my car sharper than OEM anyways.

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Looks damn good. I do love a meaty tire but it's gonna be a tough call, 205/45 slightly lowered looks amazing too...

 

[M-Sport fan]

^^^Except that HBEcoBeaST's setup, with those Indys on it, appears like a lower than 50 series profile sidewall (maybe due to the slight stretch, and the sidewall shoulder of those tires??).

(So, WHO needs the /45s??)

 

[CJ416]

^^^Except that HBEcoBeaST's setup, with those Indys on it, appears like a lower than 50 series profile sidewall (maybe due to the slight stretch, and the sidewall shoulder of those tires??).

(So, WHO needs the /45s??)

I really love how it looks, after a few days of thought I think I'm going to get /50s

 

[Im2wrxy]

I have 205/45s and I didn't notice any improvement in ride comfort (with stock suspension or after spring upgrade). I also have Dekagrams.

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[CJ416]

I have 205/45s and I didn't notice any improvement in ride comfort (with stock suspension or after spring upgrade). I also have Dekagrams.

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Thanks for the input. I'm wondering if 205/45 with nicer springs will have more comfort than 205/50 on stock springs, not sure if eibach or mountune springs will make the car rub with a taller sidewall

 

[Im2wrxy]

I switched to coilovers and it's so much better on 205/45s, and they're adjustable so there's a ton of options. It's the only way to go IMO.

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[HBEcoBeaST]

Thanks for the input. I'm wondering if 205/45 with nicer springs will have more comfort than 205/50 on stock springs, not sure if eibach or mountune springs will make the car rub with a taller sidewall

While a taller sidewall will help, suspension will make a bigger difference on ride. Stock suspension is over damped and 'bouncy'. The amount of sidewall gained with 205/45s is less than an inch. 205/50s it's technically closer to 1.5" but with stretch and vehicle weight, it's less than that. If comfort is your goal then suspension is your solution. I got these wheels tires for looks, lightweight and performance without sacrificing turn in, response or feel.

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[CJ416]

While a taller sidewall will help, suspension will make a bigger difference on ride. Stock suspension is over damped and 'bouncy'. The amount of sidewall gained with 205/45s is less than an inch. 205/50s it's technically closer to 1.5" but with stretch and vehicle weight, it's less than that. If comfort is your goal then suspension is your solution. I got these wheels tires for looks, lightweight and performance without sacrificing turn in, response or feel.

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I'm going to autocross starting in April, so performance is definitely important, but the roads in my area aren't very good, so more comfort would be nice to have if possible, but I know the two don't really go hand in hand, so adjustable coilovers may be the way to for me then...

 

[M-Sport fan]

While a taller sidewall will help, suspension will make a bigger difference on ride. Stock suspension is over damped and 'bouncy'. The amount of sidewall gained with 205/45s is less than an inch. 205/50s it's technically closer to 1.5" but with stretch and vehicle weight, it's less than that. If comfort is your goal then suspension is your solution. I got these wheels tires for looks, lightweight and performance without sacrificing turn in, response or feel.

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^^^THIS!

I am going 205/50 on my Dekas NOT for 'ride comfort', but to try (however futile that may be) and help protect these lightweight wheels from the bombed-out crater roads around here.
I am also hoping that by selecting an XL load tire, the sidewalls will be at least slightly less prone to bubbles/blowouts than an SL rated tire as well.

 

[CJ416]

^^^THIS!

I am going 205/50 on my Dekas NOT for 'ride comfort', but to try (however futile that may be) and help protect these lightweight wheels from the bombed-out crater roads around here.
I am also hoping that by selecting an XL load tire, the sidewalls will be at least slightly less prone to bubbles/blowouts than an SL rated tire as well.

Note taken! Plus I like having thicker tires to fight back against stance nation with their tires that are way too small for their oversized wheels 🤣

 

[briandee]

Bad lighting, but this is 205/50 16x7 et42 on mountune springs. Only rubs when making a hard left up a steep grade.

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[BlackBeanAndRice]

I'd have gone with the 50 this year if I went with RE71r's, but instead I'm going with Hankook R-S4's and they are only available in 45, I believe.

45 isn't quite enough padding to protect the wheels from my driving and our roads, and I red-lined a few times in 2nd gear doing autoX with 45s last year, where a touch more speed in 2nd would have been nice.

I'm just going to try to be more careful this time, lol.

 

[M-Sport fan]

Note taken! Plus I like having thicker tires to fight back against stance nation with their tires that are way too small for their oversized wheels 🤣

Yes, a bit hard to call something a 'performance car' with 185s stretched to the breaking point over 10"+ wide wheels, and 15*+ of negative camber to make it fit on their slammed to the ground, high centering on every reverse cambered turn 'rides'!!

 

[M-Sport fan]

Bad lighting, but this is 205/50 16x7 et42 on mountune springs. Only rubs when making a hard left up a steep grade.

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Easton, PA??

IF so, how does that setup handle the (unavoidable) craters/potholes in our illustrious state (and what tires on those wheels)?

 

[kevinatfms]

45 aspect ratio to keep to the closest original ride height. I had a choice between 205/45R16 and 215/45R16 and went with the closest to stock as i could. I will definitely try the .2 taller 215/45R16 next time in a BFG Rival to see if the longer gear will help at the track.

50 aspect ratio if you autocross in HS(yet you have to use 7" wide wheels in HS) as it lowers the gear ratio and you can keep it in 2nd longer before shifting. The 50 will also yield better compliance with more sidewall. The current national HS champ runs a 205/50R16 on a 16x7 wheel if that makes your willy stand.

I run 205/46R16 on an 8" wide wheel for the turn in response. Its a Federal RS-Pro so they do run wide(not as wide as the RS-RR though). It measures to a 7.6" tread width on an 8" wheels. So far its the best combo i have run on track and autocross. I dont daily my car anymore so its relegated to weekend fun duty. I can though drive over an hour to/from the track on the 45 aspect ratio without issue. I have run 205/40R17 on two different sets of wheels, a 195/55R15 on a 15x6 steelie(winter set at the time) a 205/50R15 on a 15x7 and now a 205/45R16 on a 16x8.

 

[CJ416]

45 aspect ratio to keep to the closest original ride height. I had a choice between 205/45R16 and 215/45R16 and went with the closest to stock as i could. I will definitely try the .2 taller 215/45R16 next time in a BFG Rival to see if the longer gear will help at the track.

50 aspect ratio if you autocross in HS(yet you have to use 7" wide wheels in HS) as it lowers the gear ratio and you can keep it in 2nd longer before shifting. The 50 will also yield better compliance with more sidewall. The current national HS champ runs a 205/50R16 on a 16x7 wheel if that makes your willy stand.

I run 205/46R16 on an 8" wide wheel for the turn in response. Its a Federal RS-Pro so they do run wide(not as wide as the RS-RR though). It measures to a 7.6" tread width on an 8" wheels. So far its the best combo i have run on track and autocross. I dont daily my car anymore so its relegated to weekend fun duty. I can though drive over an hour to/from the track on the 45 aspect ratio without issue. I have run 205/40R17 on two different sets of wheels, a 195/55R15 on a 15x6 steelie(winter set at the time) a 205/50R15 on a 15x7 and now a 205/45R16 on a 16x8.

It's a shame that you need to run 16x7 in HS, because I haven't found another wheel I like as much as the dekkagram. The closest is TD pro 1.2, which is really hard to find in the states. I think I'm just going to run the dekkagram and have them put me in street touring since 1. I'm a novice and won't be very competitive anyways and 2. I'm planning on getting other upgrades that would place the car in touring, so it's inevitable, might as well run the wheels I want

 

[kevinatfms]

It's a shame that you need to run 16x7 in HS, because I haven't found another wheel I like as much as the dekkagram. The closest is TD pro 1.2, which is really hard to find in the states. I think I'm just going to run the dekkagram and have them put me in street touring since 1. I'm a novice and won't be very competitive anyways and 2. I'm planning on getting other upgrades that would place the car in touring, so it's inevitable, might as well run the wheels I want

I felt the same way. I just have fun now at autocross and compete with my friends. The Dekagrams are an excellent wheel. I dont like the non-hubcentric part but it was easy enough to source some aluminum hub rings for them.

I do suggest the aluminum hub rings and a set of thin walled lugs. I went with the Muteki SR48 lugs off Amazon(cheapest ive found at under $50 shipped) along with the hub rings(think they were $9). Great little package.