Tyre size help needed!!
03-23-2011 | 01:32 AM
#1
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Tyre size help needed!!
Hi,
I have just bought a set of staggered 19" alloy wheels for my RX8, they are 8.5" wide fronts and 9.5" wide rears, i have a pair of brand new 225/40r19 tyres for the fronts but unsure of the best option for the rears, 235/40r19 or 245/40r19, I would be very grateful if you could tell me which of the following would be the best to fit tyre wise for the width, 235/40r19 or 245/40r19, any help/info would be great.
I have just bought a set of staggered 19" alloy wheels for my RX8, they are 8.5" wide fronts and 9.5" wide rears, i have a pair of brand new 225/40r19 tyres for the fronts but unsure of the best option for the rears, 235/40r19 or 245/40r19, I would be very grateful if you could tell me which of the following would be the best to fit tyre wise for the width, 235/40r19 or 245/40r19, any help/info would be great.
03-23-2011 | 02:55 AM
#2
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From: Whangarei, New Zealand
You want to make sure that the front and rear tyre diameter is as close to the same as possible.
I have the stagged setup on my car ( 19 x 8.5 & 19 x 9.5 ) and tyre sizes I went for were 235-35-19 front and 265-30-19 rear. This was the closest I could get to the same tyre diameter front and rear with the tyre brand I went for.
If you run tyre diameters that are quite different front to rear, you may find you start having problems with the DSC coming on in corners, well before it normally would.
Hope this is helpful
I have the stagged setup on my car ( 19 x 8.5 & 19 x 9.5 ) and tyre sizes I went for were 235-35-19 front and 265-30-19 rear. This was the closest I could get to the same tyre diameter front and rear with the tyre brand I went for.
If you run tyre diameters that are quite different front to rear, you may find you start having problems with the DSC coming on in corners, well before it normally would.
Hope this is helpful
03-23-2011 | 03:41 AM
#3
The 225/40/19 will be an alright fit for the front but as Rotaman said, you want to keep the outer diameter of the fronts and rears as close as possible.
Many don't know, but the profile thickness of a tire is actually calculated using the profile number as a percentage of the width. It's not too important, but relevant to mention that tire measurements are done in millimeters. So, a 225/40 will not have the same sidewall height as a 245/40 (40% of 225 (90mm) =/= 40% of 245 (98mm). What this means is that the wider the tire gets, the lower the profile number, or percentage, to keep the actual profile heights closer. A 245/35 will have a sidewall thickness of 85.75mm which is closer to the 225/40 90mm thickness than the 245/40 98mm thickness.
For the rears, your best bet would be a 245/35/19 to keep the amount of stretch/squareness, as well as outer diameter, roughly the same in front and rear, if you do use the 225/40/19's up front.
What are the offsets of the wheels? This is also important in determining how well the wheels will fit. If all this is a bit confusing, don't worry, that's what the forum is here for
Many don't know, but the profile thickness of a tire is actually calculated using the profile number as a percentage of the width. It's not too important, but relevant to mention that tire measurements are done in millimeters. So, a 225/40 will not have the same sidewall height as a 245/40 (40% of 225 (90mm) =/= 40% of 245 (98mm). What this means is that the wider the tire gets, the lower the profile number, or percentage, to keep the actual profile heights closer. A 245/35 will have a sidewall thickness of 85.75mm which is closer to the 225/40 90mm thickness than the 245/40 98mm thickness.
For the rears, your best bet would be a 245/35/19 to keep the amount of stretch/squareness, as well as outer diameter, roughly the same in front and rear, if you do use the 225/40/19's up front.
What are the offsets of the wheels? This is also important in determining how well the wheels will fit. If all this is a bit confusing, don't worry, that's what the forum is here for
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