Tire sizes. Help request
Thread Starter
Racer
Joined: Oct 2020
Posts: 389
Likes: 170
From: Rhode Island
St. Jude Donor '21
Tire sizes. Help request
My plan is to buy Cray Manta's in chrome. 18 in front, 19 in rear.
I also plan to lower on stock bolts
My 99 vert has stock wagon wheels and stock size tires. so 17x8.5 with p245/45ZR-17 in front and 18x9.5 with p275/40ZR-18 in rear.
what i want to accomplish is to fill up the wheel well a little more than now and lose the 4x4 look.
This forum has too many smaht people for me to go this alone, so i'm requesting some help in sizing the tires to accomplish that.
According to the calculations, the overall tire diameter of my current setup is 25.7" in front and 26.6" in rear.
seems like i have to go up to 275's in front to gain an inch of tire diameter. does that sound right?
the backs i think will be 285's and gain about 1.5 inch of diameter.
Anyway, what are you guys with 18/19 running for tires.?
I also plan to lower on stock bolts
My 99 vert has stock wagon wheels and stock size tires. so 17x8.5 with p245/45ZR-17 in front and 18x9.5 with p275/40ZR-18 in rear.
what i want to accomplish is to fill up the wheel well a little more than now and lose the 4x4 look.
This forum has too many smaht people for me to go this alone, so i'm requesting some help in sizing the tires to accomplish that.
According to the calculations, the overall tire diameter of my current setup is 25.7" in front and 26.6" in rear.
seems like i have to go up to 275's in front to gain an inch of tire diameter. does that sound right?
the backs i think will be 285's and gain about 1.5 inch of diameter.
Anyway, what are you guys with 18/19 running for tires.?
Race Director
Joined: Jan 2000
Posts: 10,373
Likes: 3,385
From: Central TX
C5 of Year Finalist (appearance mods) 2019
A 275/35/18 is right at 25.7" diameter and a 275/40/18 is 26.7". With the latter size, you would need a rear tire of approximately 27.6" diameter, to keep your sidewall heights close to the same stagger. On a C5, especially one lowered, tires that tall are going to create clearance issues. My suggestion would be 265/35/18 fronts @ 25.3" tall and a 305/30/19 rear @ 26.2". These are very popular sizes, with lots of tire selection. Lower the car and you're done.
Another option would be 275/35/18 fronts @ 25.7" tall and and either a 295/35/19 @ 27.1" diameter or a 305/35/19 rears @ 27.4" tall. Before you or anyone else asks, there won't be any issues with Active Handling or Traction Control, with these size combos. The AH/TC on a C5 is very forgiving of diameter differences and as long as the front tires aren't taller than the rears, you will be fine.
Another option would be 275/35/18 fronts @ 25.7" tall and and either a 295/35/19 @ 27.1" diameter or a 305/35/19 rears @ 27.4" tall. Before you or anyone else asks, there won't be any issues with Active Handling or Traction Control, with these size combos. The AH/TC on a C5 is very forgiving of diameter differences and as long as the front tires aren't taller than the rears, you will be fine.
Thread Starter
Racer
Joined: Oct 2020
Posts: 389
Likes: 170
From: Rhode Island
St. Jude Donor '21
A 275/35/18 is right at 25.7" diameter and a 275/40/18 is 26.7". With the latter size, you would need a rear tire of approximately 27.6" diameter, to keep your sidewall heights close to the same stagger. On a C5, especially one lowered, tires that tall are going to create clearance issues. My suggestion would be 265/35/18 fronts @ 25.3" tall and a 305/30/19 rear @ 26.2". These are very popular sizes, with lots of tire selection. Lower the car and you're done.
Another option would be 275/35/18 fronts @ 25.7" tall and and either a 295/35/19 @ 27.1" diameter or a 305/35/19 rears @ 27.4" tall. Before you or anyone else asks, there won't be any issues with Active Handling or Traction Control, with these size combos. The AH/TC on a C5 is very forgiving of diameter differences and as long as the front tires aren't taller than the rears, you will be fine.
Another option would be 275/35/18 fronts @ 25.7" tall and and either a 295/35/19 @ 27.1" diameter or a 305/35/19 rears @ 27.4" tall. Before you or anyone else asks, there won't be any issues with Active Handling or Traction Control, with these size combos. The AH/TC on a C5 is very forgiving of diameter differences and as long as the front tires aren't taller than the rears, you will be fine.
Last edited by djohn3853; Dec 1, 2020 at 07:47 PM.
Race Director
Joined: Jan 2000
Posts: 10,373
Likes: 3,385
From: Central TX
C5 of Year Finalist (appearance mods) 2019
Thank you for you advice USAZR1. thought i'd get more replies, but i'm sure this topic is talked to death. It's just that it's all still new to me. What do you think about 255/40-18 fronts and 285/35-19 rears. I think it checks all the boxes i want. the are bigger tire diameter than stock, and bigger tire diameter, both of which will help to fill the wheel well. They also maintain the front/rear size difference to appx an inch. Along with lowering on stock bolts, i think will get me the look i want.
Thread Starter
Racer
Joined: Oct 2020
Posts: 389
Likes: 170
From: Rhode Island
St. Jude Donor '21
i'm pretty sure he isn't lowered on stock bolts, but rather, aftermarket. i am only planning to lower on stock bolts and only expect about 1/2 to 3/4 inches.
Racer
Joined: Nov 2003
Posts: 430
Likes: 60
From: Central KY
I found this site very helpful in comparing size tires width, height, and other info.
https://tiresize.com/
https://tiresize.com/
Thread Starter
Racer
Joined: Oct 2020
Posts: 389
Likes: 170
From: Rhode Island
St. Jude Donor '21
I found this site very helpful in comparing size tires width, height, and other info.
https://tiresize.com/
https://tiresize.com/
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Melting Slicks
Joined: Jun 2013
Posts: 3,473
Likes: 691
From: West Virginia
I run 18/19's lowered. I lowered on OEM bolts (about an inch) so that the wheels were centered in the openings - i.e., the "air" over the tops of the tires was about the same as the air in front and behind the tire. I am running standard C6 tire sizes - 245/40x18 up front and 285/35x19 in the rear - as there are a lot of options in those sixes. I chose Michelin Pilot Sport All Season - we get winter here and I drive it all year round. And they have more grip than you can safely explore on public roads. Even got me home in snow a couple of times.
Thread Starter
Racer
Joined: Oct 2020
Posts: 389
Likes: 170
From: Rhode Island
St. Jude Donor '21
I run 18/19's lowered. I lowered on OEM bolts (about an inch) so that the wheels were centered in the openings - i.e., the "air" over the tops of the tires was about the same as the air in front and behind the tire. I am running standard C6 tire sizes - 245/40x18 up front and 285/35x19 in the rear - as there are a lot of options in those sixes. I chose Michelin Pilot Sport All Season - we get winter here and I drive it all year round. And they have more grip than you can safely explore on public roads. Even got me home in snow a couple of times.
Your back tire siZe is what i have decided on. the fronts i'm leaning to 255/40.
Melting Slicks
Joined: Nov 2006
Posts: 2,361
Likes: 51
From: Dallas Texas
St. Jude Donor '08
Last edited by VerTigo456; Dec 3, 2020 at 01:13 PM.
