Should I get 17s or 18s? List what mods you have and wheel specs
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Should I get 17s or 18s? List what mods you have and wheel specs
Yup it's another indecisive thread about 17" vs 18" wheels.
What am I looking for? The best performance wheel and tire set up for the track. Ideally I'd like to apply this thread to those with experience between BOTH diameters. I'd like an educated opinion for your recommendation for me and other drivers with similar applications. So share your tire, wheel, and suspension modifications. And explain why you decided to use these parts and what results over the other.
A little about me and my car. Since I bought my RX8 summer of 2013 I've managed to put about 4000 miles on my remanufactured motor. I currently have installed; Mugan rear chamber arms, Koni Yellow shocks, Mazdaspeed Springs, Hotchkis sway bars (F33,R21mm), Racing Beat end links and an upgraded underbody brace I suppose you could call a 12pt. I have some cheap 17x8 +42 MB wheels wrapped with some cheap 225/50 all seasons. I have a Honda Fit I daily so my RX8 is strictly for spirited driving ONLY. I am happy with how my suspension performs but there is always room for improvement. That being said i decided on some enkei wheels and Micheline PSS tires. I want the offset to stay as close to OEM for the best geometry results.
So let's get started,
RPF1 17x9+45 15.65 pounds
245/40R17 tire 23 pounds total weight of 38.65 or 255/40R17 about 2 pounds heavier
VS
PF01 18x9+45 19.20 pounds
255/35R18 tire 25 pounds total weight of 44.20
Difference between 17" and 18" wheels with PSS tires is approximately 5.55 pounds
What am I looking for? The best performance wheel and tire set up for the track. Ideally I'd like to apply this thread to those with experience between BOTH diameters. I'd like an educated opinion for your recommendation for me and other drivers with similar applications. So share your tire, wheel, and suspension modifications. And explain why you decided to use these parts and what results over the other.
A little about me and my car. Since I bought my RX8 summer of 2013 I've managed to put about 4000 miles on my remanufactured motor. I currently have installed; Mugan rear chamber arms, Koni Yellow shocks, Mazdaspeed Springs, Hotchkis sway bars (F33,R21mm), Racing Beat end links and an upgraded underbody brace I suppose you could call a 12pt. I have some cheap 17x8 +42 MB wheels wrapped with some cheap 225/50 all seasons. I have a Honda Fit I daily so my RX8 is strictly for spirited driving ONLY. I am happy with how my suspension performs but there is always room for improvement. That being said i decided on some enkei wheels and Micheline PSS tires. I want the offset to stay as close to OEM for the best geometry results.
So let's get started,
RPF1 17x9+45 15.65 pounds
245/40R17 tire 23 pounds total weight of 38.65 or 255/40R17 about 2 pounds heavier
VS
PF01 18x9+45 19.20 pounds
255/35R18 tire 25 pounds total weight of 44.20
Difference between 17" and 18" wheels with PSS tires is approximately 5.55 pounds
Last edited by I-luv-Doritos; 10-22-2014 at 09:31 AM. Reason: Proof reading is all
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Yup it's another indecisive thread about 17" vs 18" wheels.
What am I looking for? The best performance wheel and tire set up for the track. Ideally I'd like to apply this thread to those with experience between BOTH diameters. I'd like an educated opinion for your recommendation for me and other drivers with similar intentions. So share your tire, wheel, and suspension modifications. And explain why you decided to use these parts and what results over the other.
A little about me and my car. Since I bought my RX8 summer of 2013 I've managed to put about 4000 miles on my remanufactured motor. I currently have installed; Mugan rear chamber arms, Koni Yellow shocks, Mazdaspeed Springs, Hotchkis sway bars (F33,R21mm), Racing Beat end links and an upgraded underbody brace I suppose you could call a 12pt. I have some cheap 17x8 +42 MB wheels wrapped with some cheap 225/50 all seasons. I have a Honda Fit I daily so my RX8 is strictly for spirited driving ONLY. I am happy with how my suspension performs but there is always room for improvement. That being said i decided on some enkei wheels and Micheline PSS tires. I want the offset to stay as close to OEM for the best geometry results.
So let's get started,
RPF1 17x9+45 15.65 pounds
245/40R17 tire 23 pounds total weight of 38.65
OR
PF01 18x9+45 19.20 pounds
255/35R18 tire 25 pounds total weight of 44.20
Difference between 17" and 18" wheels with PSS tires is approximately 5.55 pounds
What am I looking for? The best performance wheel and tire set up for the track. Ideally I'd like to apply this thread to those with experience between BOTH diameters. I'd like an educated opinion for your recommendation for me and other drivers with similar intentions. So share your tire, wheel, and suspension modifications. And explain why you decided to use these parts and what results over the other.
A little about me and my car. Since I bought my RX8 summer of 2013 I've managed to put about 4000 miles on my remanufactured motor. I currently have installed; Mugan rear chamber arms, Koni Yellow shocks, Mazdaspeed Springs, Hotchkis sway bars (F33,R21mm), Racing Beat end links and an upgraded underbody brace I suppose you could call a 12pt. I have some cheap 17x8 +42 MB wheels wrapped with some cheap 225/50 all seasons. I have a Honda Fit I daily so my RX8 is strictly for spirited driving ONLY. I am happy with how my suspension performs but there is always room for improvement. That being said i decided on some enkei wheels and Micheline PSS tires. I want the offset to stay as close to OEM for the best geometry results.
So let's get started,
RPF1 17x9+45 15.65 pounds
245/40R17 tire 23 pounds total weight of 38.65
OR
PF01 18x9+45 19.20 pounds
255/35R18 tire 25 pounds total weight of 44.20
Difference between 17" and 18" wheels with PSS tires is approximately 5.55 pounds
Also, you mention that you want the offset to stay as close to oem for the best geometry, but you already changed several suspension related components .... sounds counter intuitive
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Hey thanks! Yes they are significantly cheaper and that can be a huge factor in making this decision easier. Unfortunately Michelin does not make the PSS in 255/35 or 255/40 for a 17" wheel. Sucks because I've always enjoyed the stiffness and longevity of that tire. The 18s seem to have a larger market in tires. Anyway the Mazdaspeed springs have lowered the car less than an inch. The majority of the suspension arms are factory and I am able to achieve factory recommended alignments. What components I have changed are really not that major. I had Tunabe springs prior and realized they messed with rear chamber. So that's why I had to change those out and I purchased some used chamber arms in case I run into that issue in the future.
I still don't know if 17" wheels will handle better than 18" wheels.
I still don't know if 17" wheels will handle better than 18" wheels.
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Hey thanks! Yes they are significantly cheaper and that can be a huge factor in making this decision easier. Unfortunately Michelin does not make the PSS in 255/35 or 255/40 for a 17" wheel. Sucks because I've always enjoyed the stiffness and longevity of that tire. The 18s seem to have a larger market in tires. Anyway the Mazdaspeed springs have lowered the car less than an inch. The majority of the suspension arms are factory and I am able to achieve factory recommended alignments. What components I have changed are really not that major. I had Tunabe springs prior and realized they messed with rear chamber. So that's why I had to change those out and I purchased some used chamber arms in case I run into that issue in the future.
I still don't know if 17" wheels will handle better than 18" wheels.
I still don't know if 17" wheels will handle better than 18" wheels.
Also, consider the 5 lb savings is EACH wheel. And that becomes quite significant when it is factored that it is a savings in unsprung weight.
But I guess I should ask, when you say "handle better", what exactly do you mean? There are so many factors in handling besides wheel diameter. Actually ... wheel diameter is almost a non factor in respect to handling.
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On a 17" wheel the lowest side wall ratio for a 255 tire is 40. 255/40R17 is 636mm tall.
On a 18" wheel the lowest side wall ratio for a 255 tire is 35. 255/35R18 is 635mm tall.
From the top of the tire to the bottom is equivalent! In fact that's 1mm off.
Custom rims, wheel tire packages for your ride - RIMSnTIRES.com
This website allows you to compare wheel/tire sizes. It proves to me there is no hight difference between the two and they both allow the same amount of contact. So what is the difference here? How could one benefit from one size over the other?
On a 18" wheel the lowest side wall ratio for a 255 tire is 35. 255/35R18 is 635mm tall.
From the top of the tire to the bottom is equivalent! In fact that's 1mm off.
Custom rims, wheel tire packages for your ride - RIMSnTIRES.com
This website allows you to compare wheel/tire sizes. It proves to me there is no hight difference between the two and they both allow the same amount of contact. So what is the difference here? How could one benefit from one size over the other?
Last edited by I-luv-Doritos; 10-22-2014 at 08:29 AM.
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A 245/45 17" would put you closer to OEM sizing (assuming your oem are 225/45 18"). Neither 255/35 or 255/40 are anywhere close to OEM total diameter on a 17"
Also, consider the 5 lb savings is EACH wheel. And that becomes quite significant when it is factored that it is a savings in unsprung weight.
But I guess I should ask, when you say "handle better", what exactly do you mean? There are so many factors in handling besides wheel diameter. Actually ... wheel diameter is almost a non factor in respect to handling.
Also, consider the 5 lb savings is EACH wheel. And that becomes quite significant when it is factored that it is a savings in unsprung weight.
But I guess I should ask, when you say "handle better", what exactly do you mean? There are so many factors in handling besides wheel diameter. Actually ... wheel diameter is almost a non factor in respect to handling.
But yes 5.55 lbs is a huge difference in unsprung weight. But so far that is the only clear difference. I am simply interested in the best performance wheel and tire set up. Now I can try and break that down if we want to be very specific. While driving in the canyons and on the track I want there to be a smooth and direct response on straight aways and while cornering. I know there is a lot of factors that could alter the way the car handles. But all of that can be changed in increments while aligning the car and adjust my sway bars.
How does unsprung weight benefit effect things?
Last edited by I-luv-Doritos; 10-22-2014 at 09:01 AM.
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Maybe I haven't made my self clear enough. I am not trying to achieve the stock wheel diameter. I do want to increase the width about 1" so I can have a wider tire contact. Although i do not want to slow my self down by applying too much contact. Ideally 255 is the widest tire I will apply. That being said. 255/40R17 is not different than 255/35R18. They are 1mm apart in hight even with different wheel diameter.
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Pretty much what he said. There is no 'best' setup but the above is a very good starting point. It's like asking 'what is best steak'? Most people will probably prefer filet mignon to many other things, but then you get into the aging, preparation and personal tastes. Filet mignon is a really good place to start, but maybe you'll find you want less sidewall flex or more bump tolerance. It's endless.
Btw I track 235/45/17 and was happy for a while but need more contact so will go 245 next.
Btw there are multiple ways to achieve what you're describing through alignment, suspension tuning or even just tire pressure.
I'd say go with 17s and tune for the tire. By the time you're done, you won't need a forum thread to know what changes to make.
Btw I track 235/45/17 and was happy for a while but need more contact so will go 245 next.
Btw there are multiple ways to achieve what you're describing through alignment, suspension tuning or even just tire pressure.
I'd say go with 17s and tune for the tire. By the time you're done, you won't need a forum thread to know what changes to make.
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Of course there is. There is practically a thread for every topic in the forums by now. All I ask is for people share there opinion. Drop a comment for the sake discussion. After all this is a forum.
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