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Tire Pressure New Tire Size

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Old Feb 14, 2026 | 05:47 PM
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Nelson G's Avatar
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From: Georgia
Default Tire Pressure New Tire Size

So after searching for tires, I decided on a set of Michelin Pilot Sport All-Season 4 tires. I went with the 235 40 R18 and the 275 35 R19. My question is: the original-size tires had a tire pressure of 36 lbs. With the new size, how much should the tire pressure be increased to? 40 lbs all around or more?
Thanks
Nelson
 
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Old Feb 14, 2026 | 08:15 PM
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amx1397's Avatar
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From: Indialantic Fl./blairsville Ga
Default Re: Tire Pressure New Tire Size

Stay at 36,, it is the car that wants the 36, not the tire the 235/40-18 is 25.4 tall & side wall of 9.3,
to me it is too big for the front as u make a U turn they will rub but the real reason is at 100 mph the front end starts to lift..
With the stock tire on the front no lift,,(the front stock rim is 7.5 wide) -----225/40-18 is 25.1 tall & side wall of 8.9.
I have 235/40-18 on the front of my V8 (I did not put them on) I just changed to a 18x8.5 rim, et 30 with the 225/40-18
the stock rear rim is 19x9 wide . my new rear rims will be 19x9.5 et 28
I also have a rear set for the rear 18x9.5-18 tire is a 265/40-18 at 26.4 tall. :note the 235/35-19 are10.8 side wall & 26.6 tall perfect tire for the rear
Good luck with your set up, they should work great, just remember not to hit the turning stops when making a u-turn
OH here is the chart on the stock rims on all crossfires Jim
The stock rims on a Chrysler Crossfire (all model years 2004-2008) have the following specifications, which are consistent across the standard and SRT-6 models:

Specification Front Rim Rear Rim Diameter 18 inches 19 inches
Width 7.5 inches 9 inches
Offset 35 mm 22 mm
Bolt Pattern 5x112 mm 5x112 mm
Number of Lugs 5 lugs 5 lugs
 

Last edited by amx1397; Feb 14, 2026 at 08:19 PM.
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Old Feb 15, 2026 | 11:12 AM
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copperfieldkid's Avatar
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Joined: Jan 2017
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From: Houston Texas
Default Re: Tire Pressure New Tire Size

Tire pressure for larger tires depends on the new tire's load rating. If the new tires have the same load rating, use the same pressure. It's basically the weight distribution (load) of the new tires to determine the optimal pressure. Since only size has changed I agree with amx ( 36 PSI recommended / driver's side door jamb)
 
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Old Feb 15, 2026 | 11:27 AM
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Nelson G's Avatar
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From: Georgia
Default Re: Tire Pressure New Tire Size

Originally Posted by amx1397
Stay at 36,, it is the car that wants the 36, not the tire the 235/40-18 is 25.4 tall & side wall of 9.3,
to me it is too big for the front as u make a U turn they will rub but the real reason is at 100 mph the front end starts to lift..
With the stock tire on the front no lift,,(the front stock rim is 7.5 wide) -----225/40-18 is 25.1 tall & side wall of 8.9.
I have 235/40-18 on the front of my V8 (I did not put them on) I just changed to a 18x8.5 rim, et 30 with the 225/40-18
the stock rear rim is 19x9 wide . my new rear rims will be 19x9.5 et 28
I also have a rear set for the rear 18x9.5-18 tire is a 265/40-18 at 26.4 tall. :note the 235/35-19 are10.8 side wall & 26.6 tall perfect tire for the rear
Good luck with your set up, they should work great, just remember not to hit the turning stops when making a u-turn
OH here is the chart on the stock rims on all crossfires Jim
The stock rims on a Chrysler Crossfire (all model years 2004-2008) have the following specifications, which are consistent across the standard and SRT-6 models:

Specification Front Rim Rear Rim Diameter 18 inches 19 inches
Width 7.5 inches 9 inches
Offset 35 mm 22 mm
Bolt Pattern 5x112 mm 5x112 mm
Number of Lugs 5 lugs 5 lugs

Thanks for your answer. When I did a search, those were the sizes different owners offered. I will adjust the tire pressure back to 36 as the tire store put too much in. Yes, I do hear the rubbing on the front, mostly when it is almost full lock. Other than that, the new tires run great.

Thanks for your reply.

Nelson
 
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