Tire sidewall question... Who has the facts?

Biimmer · 06-01-2010, 03:25 PM

So, I have been doing some tire research and I am seeing that a ton of people are going with a thinner sidewall for the rear tire setup ex: 235/35/19 front and 275/30/19 rear.

What is the reason for a thinner sidewall for the rear instead of maybe a thicker "rear" or perhaps a even sidewall setup?

Thanks for the help!

Tee212 · 06-01-2010, 03:33 PM

peformance aspects? hardly
most ppl choose this route due to clearance/speedo/looks

Biimmer · 06-01-2010, 03:50 PM

Still confused.. I have always thought that the "30" in a 275/30/19 tire would refer to the thickness of the sidewall. How does the width have any effect on the diameter/aspect ratio?

Thanks for the help I'm trying to learn

I335 · 06-01-2010, 03:53 PM

275 is the width of the tire
30 is the aspect ratio - 30% of the width
19 is the diameter

Tee212 · 06-01-2010, 03:56 PM

Quote:

Originally Posted by I335

275 is the width of the tire
30 is the aspect ratio - 30% of the width
19 is the diameter

3-2 =+1

Biimmer · 06-01-2010, 04:02 PM

So based on the width with a 235/35 and 275/30 the aspect ratio would be the same?
I want the sidewall thickness in the front to be equal to the rear. I wouldn't be a fan of the look when running a lower profile tire in the rear. ** if people are even doing that**

Thanks!

Biimmer · 06-01-2010, 04:07 PM

Quote:

Originally Posted by Tee212

3-2 =+1

Thanks, I didn't have a calculator handy.

kramerica72 · 06-01-2010, 04:20 PM

Quote:

Originally Posted by Biimmer

Still confused.. I have always thought that the "30" in a 275/30/19 tire would refer to the thickness of the sidewall. How does the width have any effect on the diameter/aspect ratio?

Thanks for the help I'm trying to learn

If you are talking about the distance from the rim edge to the tread, you'll want to refer to it as "sidewall height."

Sidewall "thickness" denotes something else completely--(i.e. RFT sidewalls are thicker so they won't collapse when punctured)

Biimmer · 06-01-2010, 04:55 PM

Quote:

Originally Posted by kramerica72

If you are talking about the distance from the rim edge to the tread, you'll want to refer to it as "sidewall height."

Sidewall "thickness" denotes something else completely--(i.e. RFT sidewalls are thicker so they won't collapse when punctured)

Thx, but you know what I'm refferimg to as my initial question was not about "Run Flats".

Biimmer · 06-01-2010, 05:14 PM

BTW Thanks to everyone who helped :-)

Orient330iNYC · 06-01-2010, 09:47 PM

275/30/19

275 is the width
30 is the aspect ratio, ratio of sidewall height to width.

so the sidewall height is 275 *0.30=82.5mm
235/35/19
235*0.35= 82.25mm

sidewall height almost exactly the same

Biimmer · 06-02-2010, 12:39 AM

Quote:

Originally Posted by Orient330iNYC

275/30/19

275 is the width
30 is the aspect ratio, ratio of sidewall height to width.

so the sidewall height is 275 *0.30=82.5mm
235/35/19
235*0.35= 82.25mm

sidewall height almost exactly the same

Thanks, I completely understand now

Hey, I guess you learn something new everyday!

Gary@TireRack · 06-02-2010, 12:13 PM

Tech Rat's first reply had a link explaining it all.

Biimmer · 06-02-2010, 09:33 PM

Quote:

Originally Posted by Gary@TireRack

Tech Rat's first reply had a link explaining it all.

Thanks Mr. TireRack.

06-01-2010, 03:25 PM	#1
Biimmer Private First Class 70 Rep 108 Posts Drives: G80 Join Date: Jun 2010 Location: Phoenix, AZ iTrader: (0)	Tire sidewall question... Who has the facts? So, I have been doing some tire research and I am seeing that a ton of people are going with a thinner sidewall for the rear tire setup ex: 235/35/19 front and 275/30/19 rear. What is the reason for a thinner sidewall for the rear instead of maybe a thicker "rear" or perhaps a even sidewall setup? Thanks for the help!
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06-01-2010, 03:33 PM	#2
Tee212 Banned 81 Rep 4,541 Posts Drives: yes Join Date: Oct 2008 Location: Riverside iTrader: (9) Garage List 2010 335 [8.00]	peformance aspects? hardly most ppl choose this route due to clearance/speedo/looks
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06-01-2010, 03:50 PM	#3
Biimmer Private First Class 70 Rep 108 Posts Drives: G80 Join Date: Jun 2010 Location: Phoenix, AZ iTrader: (0)	Still confused.. I have always thought that the "30" in a 275/30/19 tire would refer to the thickness of the sidewall. How does the width have any effect on the diameter/aspect ratio? Thanks for the help I'm trying to learn
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06-01-2010, 03:53 PM	#4
I335 Brigadier General 123 Rep 4,249 Posts Drives: '08 335i Coupe Join Date: Jan 2008 Location: New England iTrader: (11)	275 is the width of the tire 30 is the aspect ratio - 30% of the width 19 is the diameter
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06-01-2010, 04:02 PM	#6
Biimmer Private First Class 70 Rep 108 Posts Drives: G80 Join Date: Jun 2010 Location: Phoenix, AZ iTrader: (0)	So based on the width with a 235/35 and 275/30 the aspect ratio would be the same? I want the sidewall thickness in the front to be equal to the rear. I wouldn't be a fan of the look when running a lower profile tire in the rear. if people are even doing that Thanks!
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06-01-2010, 05:14 PM	#10
Biimmer Private First Class 70 Rep 108 Posts Drives: G80 Join Date: Jun 2010 Location: Phoenix, AZ iTrader: (0)	BTW Thanks to everyone who helped :-)
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06-01-2010, 09:47 PM	#11
Orient330iNYC Brigadier General 1469 Rep 3,552 Posts Drives: 2023 X7 40i Join Date: Apr 2007 Location: Wall St iTrader: (2)	275/30/19 275 is the width 30 is the aspect ratio, ratio of sidewall height to width. so the sidewall height is 275 0.30=82.5mm 235/35/19 2350.35= 82.25mm sidewall height almost exactly the same __________________ Present: 2023 G07 40i ZDH/ZDU/ZMP/ZMQ/2NH/ZPK/ZPP/ZRC/300/3AC Past: 2013 335i 6MT ZMM/ZDH/ZTP/3AG/494/508 Past: 2016 F34 335i xDrive ZCW/ZDA/ZDH/ZTP/ZMP/2V5/5DL Past: 2019 G01 M40i ZDA/2VF/ZPP/ZPX/688/3AC
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06-02-2010, 12:13 PM	#13
Gary@TireRack Moderator 369 Rep 4,745 Posts Drives: Formerly 1995 M3 Join Date: Oct 2006 Location: South Bend, IN, Tire Rack HQ iTrader: (2)	Tech Rat's first reply had a link explaining it all. __________________ Gary. Tire and Wheel Forum Moderator. Tire Rack Sales Rep Gary@Tirerack.com http://www.tirerack.com/a.jsp?a=AH8&url=index.jsp Please refer to 'Gary/E90 Post' as your previous contact when you order online to help support this forum.
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