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Discussion Starter #1
I'm looking for new tires to replace the oem's. I'm ok with the oem 18" wheels. Any advice on how wide i can go without rubbing/etc.?
 

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It's not a matter of what you can get on your 18"s before rubbing, it's a matter of what you can get on your 18"s, period. You didn't say the width of your OEM 18"s and I don't easily see it online but I'll guess 8" wide. An 8" wide wheel shouldn't have anything more than 255 recommended. The other thing to consider is you want to stay in the 'green zone' of the tire size calculator. So, since I believe your car came with a 225/50 OEM tire size, and you want to go wider, I think your best choices are 245/45 or 255/45. Fit your rim and land in the green zone. The 275 and 285s are in the green zone and shouldn't rub but are too wide for your rim.


90525
 

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Discussion Starter #3
It's not a matter of what you can get on your 18"s before rubbing, it's a matter of what you can get on your 18"s, period. You didn't say the width of your OEM 18"s and I don't easily see it online but I'll guess 8" wide. An 8" wide wheel shouldn't have anything more than 255 recommended. The other thing to consider is you want to stay in the 'green zone' of the tire size calculator. So, since I believe your car came with a 225/50 OEM tire size, and you want to go wider, I think your best choices are 245/45 or 255/45. Fit your rim and land in the green zone. The 275 and 285s are in the green zone and shouldn't rub but are too wide for your rim.


View attachment 90525
Thank you! I think I'm going with the ContinentalExtreme Contact DWS 06 255/45 R18. Many on here seem to like them and they get good reviews.
 

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Thank you! I think I'm going with the ContinentalExtreme Contact DWS 06 255/45 R18. Many on here seem to like them and they get good reviews.
You're welcome. Just double check your rim width. If, for whatever reason, it was, say 7.5" wide, then you'd want to stick with the 245. If it was 9", you could go with 275! But mostly likely it is 8" or 8.5" and a 255/45 is good.
 

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Discussion Starter #5
You're welcome. Just double check your rim width. If, for whatever reason, it was, say 7.5" wide, then you'd want to stick with the 245. If it was 9", you could go with 275! But mostly likely it is 8" or 8.5" and a 255/45 is good.
I did a double check and tho it's difficult to measure with the tire on it appears to be 7.5. I'll have to stick with 245s as the widest unless i $huck for new wheels too. Thx again for the pointers.
 

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My 2019 awd 3.0t luxe has stock 18's that are 7.5'' wide. It currently has the stock Bridgestone RFT 225/50, are you saying I wouldn't see any issues or premature treadwear if I went with 245/45 Michelin pilot sports a/s 3+?
 

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I did a double check and tho it's difficult to measure with the tire on it appears to be 7.5. I'll have to stick with 245s as the widest unless i $huck for new wheels too. Thx again for the pointers.
Oh, bummer. The width should be stamped on the rim, you shouldn't have to measure it manually.


My 2019 awd 3.0t luxe has stock 18's that are 7.5'' wide. It currently has the stock Bridgestone RFT 225/50, are you saying I wouldn't see any issues or premature treadwear if I went with 245/45 Michelin pilot sports a/s 3+?
245/45 is a perfectly good aftermarket size for an OEM 225/50 tire size. It will be 0.7% smaller in overall outside diameter but that is within acceptable range.
 

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Discussion Starter #8
Oh, bummer. The width should be stamped on the rim, you shouldn't have to measure it manually.




245/45 is a perfectly good aftermarket size for an OEM 225/50 tire size. It will be 0.7% smaller in overall outside diameter but that is within acceptable range.
I checked to see if I could find the size stamp and was unable hence to attempt to measure. I noticed a 245/50/18 size that fits a 7.5 rim. This would give the same diameter but a bit wider if I'm understanding things correctly. Tiresize.com says "the 245/50R18 Continental ExtremeContact DWS 06 has a diameter of 27.6", a width of 10", mounts on a 18" rim and has 751 revolutions per mile. It weighs 28 lbs, has a max load of 1764 lbs, a maximum air pressure of 51 psi, a tread depth of 10/32" and should be used on a rim width of 7-8.5". " This size appears to be a fit...any idea if I'm off base here?
 

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I checked to see if I could find the size stamp and was unable hence to attempt to measure. I noticed a 245/50/18 size that fits a 7.5 rim. This would give the same diameter but a bit wider if I'm understanding things correctly. Tiresize.com says "the 245/50R18 Continental ExtremeContact DWS 06 has a diameter of 27.6", a width of 10", mounts on a 18" rim and has 751 revolutions per mile. It weighs 28 lbs, has a max load of 1764 lbs, a maximum air pressure of 51 psi, a tread depth of 10/32" and should be used on a rim width of 7-8.5". " This size appears to be a fit...any idea if I'm off base here?
Hmmm... starting to repeat myself..... but that's ok. ;)

No, you'll want 245/45, not 245/50, as a suitable replacement tire size for your OEM 225/50 (please confirm that is your OEM size). As stated in post #7, 245/45 will be 0.7% smaller in diameter than your original 225/50s. That is acceptable (less than 1% off).

Your OEM tire diameter is 26.9". A 245/45 is 26.7". Thus, -0.7%. If your proposed 245/50 is, in fact, D = 27.6", then you are off [(27.6 - 26.9) / 26.9] = +2.6%. That is too much in my opinion and outside the preferable 'green zone'. Please look back to the image I posted in post # 2.

245/45-R18 is my recommendation. But it's your decision! Good luck.
 

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Discussion Starter #10
Hmmm... starting to repeat myself..... but that's ok. ;)

No, you'll want 245/45, not 245/50, as a suitable replacement tire size for your OEM 225/50 (please confirm that is your OEM size). As stated in post #7, 245/45 will be 0.7% smaller in diameter than your original 225/50s. That is acceptable (less than 1% off).

Your OEM tire diameter is 26.9". A 245/45 is 26.7". Thus, -0.7%. If your proposed 245/50 is, in fact, D = 27.6", then you are off [(27.6 - 26.9) / 26.9] = +2.6%. That is too much in my opinion and outside the preferable 'green zone'. Please look back to the image I posted in post # 2.

245/45-R18 is my recommendation. But it's your decision! Good luck.
Thanks again. Can you post the link to the website where you got that image in post #2?
 

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Thanks again. Can you post the link to the website where you got that image in post #2?
You are welcome. There are several tire calculator sites and some have some features that others don't but I like this one a lot.

 

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Could somebody who knows where the width stamp on the rim is, take a pic and post it? I can't find it
I think I might recall from my OEM RS400 wheels, that it's stamped on the back of a spoke. And it will end with J. You'll see 18X7.5J, for instance.
 

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A Basic Guide to Wheel Markings



Many wheels have measurement information marked on them. If you can find and understand the markings, you won't have to measure them yourself.
How to Find the Markings
Wheel markings can be found on the backside of the hub or spokes. Sometimes they can also be found on the inside edge of the rim.
  1. Remove the wheel.
  2. Clean the wheel.
  3. Place the wheel face down.
  4. Inspect the wheel for any markings.
If your wheel is marked, you may find the Brand, Model, Part Number, Load Rating, and markings that looks like this:
7J x 16 H2 5/120 ET47
What the Markings Mean
Click the blue links for more information.
7 = Wheel Width
J = Bead Profile
  • This is the size and shape of the lip where the tire bead is mounted. "J" is the most common and is used on most passenger cars.
Wheel Bead Profile Diagram
x = Wheel Construction
  • In this case, "x" means the wheel was constructed in one piece.
16 = Wheel Diameter
H2 = Wheel Flange
  • The flange is a bulge on the surface where the tire bead is mounted. This bulge helps prevent the tire from falling into the wheel.
  • The letter and number combinations specify the type, size, and shape of the flange.
5/120 = Bolt Pattern
  • The first number is the number of bolts or lugs. The number following the slash is the size of the imaginary circle formed by the center of the bolt holes in the wheel.
ET47 = Offset
  • In this example, the wheel has a positive offset of 47mm.
Notes
  • The combination of letters and numbers used in this example are ONLY an example.
  • The markings on your wheels may be split up into multiple locations.
  • There is no industry standard on location or format of wheel markings.
 

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Discussion Starter #15
A Basic Guide to Wheel Markings



Many wheels have measurement information marked on them. If you can find and understand the markings, you won't have to measure them yourself.
How to Find the Markings
Wheel markings can be found on the backside of the hub or spokes. Sometimes they can also be found on the inside edge of the rim.
  1. Remove the wheel.
  2. Clean the wheel.
  3. Place the wheel face down.
  4. Inspect the wheel for any markings.
If your wheel is marked, you may find the Brand, Model, Part Number, Load Rating, and markings that looks like this:
7J x 16 H2 5/120 ET47
What the Markings Mean
Click the blue links for more information.
7 = Wheel Width
J = Bead Profile
  • This is the size and shape of the lip where the tire bead is mounted. "J" is the most common and is used on most passenger cars.
Wheel Bead Profile Diagram
x = Wheel Construction
  • In this case, "x" means the wheel was constructed in one piece.
16 = Wheel Diameter
H2 = Wheel Flange
  • The flange is a bulge on the surface where the tire bead is mounted. This bulge helps prevent the tire from falling into the wheel.
  • The letter and number combinations specify the type, size, and shape of the flange.
5/120 = Bolt Pattern
  • The first number is the number of bolts or lugs. The number following the slash is the size of the imaginary circle formed by the center of the bolt holes in the wheel.
ET47 = Offset
  • In this example, the wheel has a positive offset of 47mm.
Notes
  • The combination of letters and numbers used in this example are ONLY an example.
  • The markings on your wheels may be split up into multiple locations.
  • There is no industry standard on location or format of wheel markings.
Great info! Dude how & where did you learn all this?
 

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Could somebody who knows where the width stamp on the rim is, take a pic and post it? I can't find it

This is what it looks like on the back of my 19 inch OEM. The "47" is the wheel offset. "19X9" is diameter and width. There are other markings on the other spokes too.
90578
 
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