Treyzian
08-07-2013, 02:16 AM
More info will be added as well as pictures.
Guide Overview
This guide is meant to review the different aspects of wheel and tire sizing and fitment. It will not only help you select a properly fitting wheel (cosmetically), but will also help you choose a correctly fitting tire.
Vice versa, this guide will help you select a tire size for maximum grip and performance, as well as a wheel that will properly fit that tire.
*For detailed info, please read RED SECTIONS 1 and 2.*
*For a quick guide, please read RED SECTION 3.*
1) General Info
Bolt Pattern of Wheels
Wheels used on the Evo X must have a 5x114.3 (5x4.5") bolt pattern. For wheels that have two bolt patterns (like 5x100/5x114.3 or 5x114.3/5x120), one of those bolt patterns must be 5x114.3 in order for that wheel to fit.
Wheel Width
The common width of wheels for this application can range anywhere between 8.5" and 10.5". WIDTH ALONE MEANS NOTHING. It must be combined with offset to determine if and how a wheel will fit on the car. Where a 8.5" wide +48 offset wheel will fit just fine, an 9" wide +48 offset wheel will not due to the lack of inner clearance with the rear vertical control arms and caliper clearance issues.
Lug Nut Size
12 x 1.5mm
Offset
Factory Evo X wheel spec: 18x8.5" ; +38 offset ; 5x114.3 ; 67.1mm centerbore (applies to all Evo X models and most Mitsubishi cars)
Offset is the measured distance in millimeters between the centerline of the wheel and the hub mounting surface (where the wheel hub mounts up against the brake rotor/drum hub).
The basic principal behind offset is that all things being equal, the higher the offset the wheel is, the more tucked the wheel will be. The lower the offset, the farther the wheel will protrude.
Example: a 18x9.5" wheel with a +15 offset will protrude out an extra 15mm when compared to a 18x9.5" +30 offset wheel. In retrospect, the +30 offset 18x9.5" will be pushed 15mm closer into the wheel well when compared to the +15 offset 18x9.5".
Given the many sizes of wheels that are designed for the Evo X (and similar platforms) offset should be between +15 and +38 (depending on wheel width).
While offset is SOLELY a measurement of wheel parameters, offset does play a role in determining if a certain size tire will fit and not rub any suspension/body components.
Width/Offset Recommendations
Here's a reference for offset ranges that can be used safely for different width wheels. Remember that these values will differ based upon suspension modifications.
8.5": +10 to +38 (Common offset is +38 on OEM wheels)
9" : +12 to +38 (Less common width = no common offset)
9.5": +15 to +30 (Common offset is +15 such as RPF1's)
10": +15 to +22 (Less common width = no common offset)
10.5" : +15 to +22 (Common offsets include +15 and +22. While both are used, +22 fit the best due to less poke)
Hubcentric Rings
The principle of hubcentric rings is as follows:
You have 3 spinning circular objects (the axle hub, the brake rotor, and the wheel/tire combo). So just imagine a small circle (axle hub), a bigger circle (brake rotor), and the biggest circle (wheel/tire combo). The ideal situation is to have the center most SINGLE POINT of all three circles to be exactly the same. If one circle isn't spinning on the same axis as the other two, the total motion of all three circles combined won't make a circle, but instead will combine to make an oval. Imagine if your wheels and tires were shaped like ovals, you'd get vibrations at speed.
The hubcentric ring compensates for differences between the centerbore of the brake rotor and axle hub, and between the centerbore of the wheel and axle hub. It allows the brake rotor and/or the wheel/tire combo to be better positioned on the hub so that the center most point of all three parts are the same. In the case with my current SSR wheels, the centerbores are bigger than the centerbores of the axle hubs so the center most point of the wheels isn't the same as the center most point of the axle hubs.
Here's what a hub centric ring looks like:
http://img845.imageshack.us/img845/5715/worldofwheels2011075.jpg
Here's what a centerbore looks like without a hubcentric ring:
http://suxorz.com/images/2013/08/07/K0SV7.jpg
Here's what the centerbore looks like with a hubcentric ring:
http://img716.imageshack.us/img716/8010/worldofwheels2011077.jpg
http://img824.imageshack.us/img824/5623/worldofwheels2011078.jpg
So lets say that you order a set of wheels that have a 73.1mm centerbore, you'd have to order centering rings that have a 73.1mm outer diameter and a 67.1mm inner diameter. If the wheels have a 75mm centerbore, you'd need rings that have a 75mm outer diameter with a 67.1mm inner diameter.
Recommended Tire Sizes (Performance, not "Stance")
18x8.5" - 245/40-18
18x9.0" - 255/40-18 ; 255/35-18
18x9.5" - 265/35-18
18x10" - 275/35-18
18x10.5" - 285/35-18 ; 285/30-18
19x9.5" - 265/35-19 ; 265/30-19
19x10" - 275/30-19
19x10.5" - 285/30-19 ; 285/25-19
Example:
In the tire size 265/35-18, 265 is the section width of the tire in millimeters. 35 is the aspect ratio (percentage) of the sidewall compared to the section width of the tire.
Example: the sidewall of a 35 series tire is 35% of the section width of the tire, which is equal to 92.75 millimeters for a 265/35-18 tire. The last number in the tire size is the required rim diameter needed to mount a specific tire.
This link will give you a good idea about changing your tire size and the effects it'll have on your speedo/odometer:
Tire size calculator (http://www.miata.net/garage/tirecalc.html)
If you decide to use ANY tire size that's not listed in the aforementioned size list, you WILL experience noticeable negative effects in the accuracy of your speedometer, odometer, ABS (Anti-lock Braking System), and (TCS) Traction Control System, which can and more than likely will decrease passenger safety... Take this statement close to heart.
2) More Complex Aspects
Lowered Suspensions & Different Wheels
Now that you hopefully understand what offset is and the parameters surrounding tire sizes, it's time to combine the two.
A common question on this board is "Will I rub?" or "Will this fit?" Offset plays very little a role in determining if your FRONT TIRES will rub on something inside the wheel well. Offset plays a large role in determining if your wheel/tire combo will rub the REAR control arms. To reiterate, offset is very important in determining if a wheel/tire combo will rub in the rear, but not nearly as important in the front.
Alignment: It's Effect on Performance as well as Fitment
An alignment is crucial to your new wheel/tire setup. It not only provides you with maximum grip, but can also be manipulated to fit different sized wheels better.
"Aggressive Street" Alignment
The general rule of thumb is:
Front:
Toe: 0*
Camber: -1.5* to -2* each side
Rear:
Toe: 0* (or the stock 3mm toe in)
Camber: -1*
The "Aggressive Street" Alignment is optimized for decent treadwear while maximizing traction. Alignment specs should be customized to your personal driving habits as well as the driving environment. Please speak with your Alignment specialist for specifics.
Fender Modifications
Generally, the width that you will need fender modifications for is 9.5 and wider (18" wheels).
18x9.5" +22 : No rolling necessary.
18x9.5" +15 : Slight rolling needed in the rear ; front rolling is optional.
18x10.5" +22 : Slight rolling needed in the rear ; front rolling is optional.
18x10.5" +15 : Rolling needed in the rear ; Slight rolling needed in the front ; Pull is optional
3) The Simple Short QUICK Guide Remember that these values will differ based upon suspension modifications.
Wheel Sizes Proven to Work Well
Wheel sizes that are most commonly used for the Evo X:
18x9.5" +15 (Best 9.5" fitment ; arguably Best wheel fitment cosmetically for the X)
18x9.5" +22 (Good fitment for stock to moderate drop)
18x10.5" +15
18x10.5" +22 (Best 10.5" fitment ; arguably Best width for performance for the X)
Recommended Tire Sizes (Performance, not "Stance")
Tire sizes that are most commonly used for the Evo X:
18x9.5" - 265/35-18
18x10.5" - 285/35-18 ; 285/30-18
Fender Modifications
Fender modifications that are necessary/recommended for the Evo X:
18x9.5" +22 : No rolling necessary.
18x9.5" +15 : Slight rolling needed in the rear ; front rolling is optional.
18x10.5" +22 : Slight rolling needed in the rear ; front rolling is optional.
18x10.5" +15 : Rolling needed in the rear ; Slight rolling needed in the front ; Pull is optional
Guide Overview
This guide is meant to review the different aspects of wheel and tire sizing and fitment. It will not only help you select a properly fitting wheel (cosmetically), but will also help you choose a correctly fitting tire.
Vice versa, this guide will help you select a tire size for maximum grip and performance, as well as a wheel that will properly fit that tire.
*For detailed info, please read RED SECTIONS 1 and 2.*
*For a quick guide, please read RED SECTION 3.*
1) General Info
Bolt Pattern of Wheels
Wheels used on the Evo X must have a 5x114.3 (5x4.5") bolt pattern. For wheels that have two bolt patterns (like 5x100/5x114.3 or 5x114.3/5x120), one of those bolt patterns must be 5x114.3 in order for that wheel to fit.
Wheel Width
The common width of wheels for this application can range anywhere between 8.5" and 10.5". WIDTH ALONE MEANS NOTHING. It must be combined with offset to determine if and how a wheel will fit on the car. Where a 8.5" wide +48 offset wheel will fit just fine, an 9" wide +48 offset wheel will not due to the lack of inner clearance with the rear vertical control arms and caliper clearance issues.
Lug Nut Size
12 x 1.5mm
Offset
Factory Evo X wheel spec: 18x8.5" ; +38 offset ; 5x114.3 ; 67.1mm centerbore (applies to all Evo X models and most Mitsubishi cars)
Offset is the measured distance in millimeters between the centerline of the wheel and the hub mounting surface (where the wheel hub mounts up against the brake rotor/drum hub).
The basic principal behind offset is that all things being equal, the higher the offset the wheel is, the more tucked the wheel will be. The lower the offset, the farther the wheel will protrude.
Example: a 18x9.5" wheel with a +15 offset will protrude out an extra 15mm when compared to a 18x9.5" +30 offset wheel. In retrospect, the +30 offset 18x9.5" will be pushed 15mm closer into the wheel well when compared to the +15 offset 18x9.5".
Given the many sizes of wheels that are designed for the Evo X (and similar platforms) offset should be between +15 and +38 (depending on wheel width).
While offset is SOLELY a measurement of wheel parameters, offset does play a role in determining if a certain size tire will fit and not rub any suspension/body components.
Width/Offset Recommendations
Here's a reference for offset ranges that can be used safely for different width wheels. Remember that these values will differ based upon suspension modifications.
8.5": +10 to +38 (Common offset is +38 on OEM wheels)
9" : +12 to +38 (Less common width = no common offset)
9.5": +15 to +30 (Common offset is +15 such as RPF1's)
10": +15 to +22 (Less common width = no common offset)
10.5" : +15 to +22 (Common offsets include +15 and +22. While both are used, +22 fit the best due to less poke)
Hubcentric Rings
The principle of hubcentric rings is as follows:
You have 3 spinning circular objects (the axle hub, the brake rotor, and the wheel/tire combo). So just imagine a small circle (axle hub), a bigger circle (brake rotor), and the biggest circle (wheel/tire combo). The ideal situation is to have the center most SINGLE POINT of all three circles to be exactly the same. If one circle isn't spinning on the same axis as the other two, the total motion of all three circles combined won't make a circle, but instead will combine to make an oval. Imagine if your wheels and tires were shaped like ovals, you'd get vibrations at speed.
The hubcentric ring compensates for differences between the centerbore of the brake rotor and axle hub, and between the centerbore of the wheel and axle hub. It allows the brake rotor and/or the wheel/tire combo to be better positioned on the hub so that the center most point of all three parts are the same. In the case with my current SSR wheels, the centerbores are bigger than the centerbores of the axle hubs so the center most point of the wheels isn't the same as the center most point of the axle hubs.
Here's what a hub centric ring looks like:
http://img845.imageshack.us/img845/5715/worldofwheels2011075.jpg
Here's what a centerbore looks like without a hubcentric ring:
http://suxorz.com/images/2013/08/07/K0SV7.jpg
Here's what the centerbore looks like with a hubcentric ring:
http://img716.imageshack.us/img716/8010/worldofwheels2011077.jpg
http://img824.imageshack.us/img824/5623/worldofwheels2011078.jpg
So lets say that you order a set of wheels that have a 73.1mm centerbore, you'd have to order centering rings that have a 73.1mm outer diameter and a 67.1mm inner diameter. If the wheels have a 75mm centerbore, you'd need rings that have a 75mm outer diameter with a 67.1mm inner diameter.
Recommended Tire Sizes (Performance, not "Stance")
18x8.5" - 245/40-18
18x9.0" - 255/40-18 ; 255/35-18
18x9.5" - 265/35-18
18x10" - 275/35-18
18x10.5" - 285/35-18 ; 285/30-18
19x9.5" - 265/35-19 ; 265/30-19
19x10" - 275/30-19
19x10.5" - 285/30-19 ; 285/25-19
Example:
In the tire size 265/35-18, 265 is the section width of the tire in millimeters. 35 is the aspect ratio (percentage) of the sidewall compared to the section width of the tire.
Example: the sidewall of a 35 series tire is 35% of the section width of the tire, which is equal to 92.75 millimeters for a 265/35-18 tire. The last number in the tire size is the required rim diameter needed to mount a specific tire.
This link will give you a good idea about changing your tire size and the effects it'll have on your speedo/odometer:
Tire size calculator (http://www.miata.net/garage/tirecalc.html)
If you decide to use ANY tire size that's not listed in the aforementioned size list, you WILL experience noticeable negative effects in the accuracy of your speedometer, odometer, ABS (Anti-lock Braking System), and (TCS) Traction Control System, which can and more than likely will decrease passenger safety... Take this statement close to heart.
2) More Complex Aspects
Lowered Suspensions & Different Wheels
Now that you hopefully understand what offset is and the parameters surrounding tire sizes, it's time to combine the two.
A common question on this board is "Will I rub?" or "Will this fit?" Offset plays very little a role in determining if your FRONT TIRES will rub on something inside the wheel well. Offset plays a large role in determining if your wheel/tire combo will rub the REAR control arms. To reiterate, offset is very important in determining if a wheel/tire combo will rub in the rear, but not nearly as important in the front.
Alignment: It's Effect on Performance as well as Fitment
An alignment is crucial to your new wheel/tire setup. It not only provides you with maximum grip, but can also be manipulated to fit different sized wheels better.
"Aggressive Street" Alignment
The general rule of thumb is:
Front:
Toe: 0*
Camber: -1.5* to -2* each side
Rear:
Toe: 0* (or the stock 3mm toe in)
Camber: -1*
The "Aggressive Street" Alignment is optimized for decent treadwear while maximizing traction. Alignment specs should be customized to your personal driving habits as well as the driving environment. Please speak with your Alignment specialist for specifics.
Fender Modifications
Generally, the width that you will need fender modifications for is 9.5 and wider (18" wheels).
18x9.5" +22 : No rolling necessary.
18x9.5" +15 : Slight rolling needed in the rear ; front rolling is optional.
18x10.5" +22 : Slight rolling needed in the rear ; front rolling is optional.
18x10.5" +15 : Rolling needed in the rear ; Slight rolling needed in the front ; Pull is optional
3) The Simple Short QUICK Guide Remember that these values will differ based upon suspension modifications.
Wheel Sizes Proven to Work Well
Wheel sizes that are most commonly used for the Evo X:
18x9.5" +15 (Best 9.5" fitment ; arguably Best wheel fitment cosmetically for the X)
18x9.5" +22 (Good fitment for stock to moderate drop)
18x10.5" +15
18x10.5" +22 (Best 10.5" fitment ; arguably Best width for performance for the X)
Recommended Tire Sizes (Performance, not "Stance")
Tire sizes that are most commonly used for the Evo X:
18x9.5" - 265/35-18
18x10.5" - 285/35-18 ; 285/30-18
Fender Modifications
Fender modifications that are necessary/recommended for the Evo X:
18x9.5" +22 : No rolling necessary.
18x9.5" +15 : Slight rolling needed in the rear ; front rolling is optional.
18x10.5" +22 : Slight rolling needed in the rear ; front rolling is optional.
18x10.5" +15 : Rolling needed in the rear ; Slight rolling needed in the front ; Pull is optional