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Hello,

I bought my '97 last November w/ matching tires from 2013. I replaced the rears immediately b/c of a slow leak in the wheel - according to the shop, the sidewall essentially broke apart when put on the tire machine. I'm leaning towards replacing the fronts (probably a no brainer). It's tough b/c they work just fine and have LOTS of tread left. On the other hand, they're likely rock hard, and I'd hate for one to fail.

The rears are Michelin Pilot Sport N3's, 295/30ZR18, and even though purchased last November, they have 2019 date codes. When I bought the rears, I didn't give much thought to going wider and wish I had. I'm confident the wheels (unsure of exact width) would take wider tires. In addition to failing to measure the wheels w/ tires off, I also neglected to weight the wheels sans tires. Lesson for next time.

"Next time" is likely now if I replace my front tires. Current tires are 245/40R18. If I jump to a 265/35R18, I can get the Michelin Pilot Sport PS2 N3 which should match my rear tires, I think. Should this be a consideration? According to this (245/40R18 Tires), these will be 4/10" (1.6%) smaller diameter and 8/10" wider. I'm guessing my front wheels are 9" (have not confirmed), and the edges of the front wheels protrude past the tire.

Questions:
1. Are there pros/cons to front and rear tires matching? If I didn't go w/ N3's in this size, I'd likely go w/ Pilot Sport 4S's in my existing size.
2. What should I be thinking about re changing size? 1.6% smaller diameter seems negligible. What about pros/cons to increased width? I recognize advantages to larger contact patch for braking and grip. Disadvantages would be increase in weight and rolling resistance and more hydroplane potential. I don't plan to do much wet driving.
3. Is there a universe where 7.5 year old tires are okay to run on a high performance car? Didn't think so...

I appreciate any insight from the group.

Thank you,
Erin
Wheel Tire Vehicle Car Automotive tire

Wheel Tire Sky Car Vehicle
 

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Nice Supra!

It appears your fronts are Advan Neovas, which are very high quality sports tires. At 7.5 years old they're almost certainly harder/reduced grip vs new, but unless you see obvious cracking/discoloration/condition issues, they are almost certainly safe to drive for another 1-2 seasons or until they wear out. If they're not worn out first, I generally discard tires when I see cracking or condition issues, or they're 10 years old.

The 1.6% difference in total height is not an issue. It becomes an issue around 8-10% difference in total tire height. For rear tire width, I'd go taller not wider. A 295/35/18 will offer better ride quality as well as superior straightline traction vs an otherwise identical tire in 295/30. Though that adds to the total tire height difference to be mindful of, but a 295/30 or 295/35 rear tire still matches a 265/35/18 front quite effectively on a MK4, provided the wheels are the correct size and offset to fit those sizes under a MK4. Your wheels appear to be that. But often times narrower tires are used to compensate for excessively aggressive wheel offsets, so I'd be sure of potential tire clearance at full steering lock before going to a 265/35 up front.
 
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Note that 295/30/18s are shorter than 265/35/18s. Unless you have coilovers, you will not be able to eliminate the "reverse" rake (had this combo before with coilvers). The solution for me, and as @Wreckless described above, is to go 295/35/18s in the rear. See below (went to 275/35s up front when I went with 295/35s out back but the point remains):

 

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Discussion Starter · #4 ·
@Wreckless, much appreciated. It had not occurred to me to check lock-to-lock, and I will. I believe I'll be okay although will confirm. Great thought re rear size as well. It will hopefully be some time before I'm faced w/ that decision (whew, tires are pricey these days).

@KenHenderson, you blew my mind a little as it never occurred to me to compare height to the rears. Well done! Using Tire Size Comparison, I see what you're talking about. The difference is minor although not ideal in my rear-tires-should-be-bigger-if-different mind. Regardless, I have Tein coilovers and can adjust as required. I've been wanting to make some adjustments anyway and learn more about them.

I stopped by the shop today and spoke to the owner. I pulled the trigger. I will be putting some miles on my car this fall/winter and will appreciate the peace of mind and any improvements.

Thank you for your advice and tips!

Erin

 

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Note that 295/30/18s are shorter than 265/35/18s. Unless you have coilovers, you will not be able to eliminate the "reverse" rake (had this combo before with coilvers). The solution for me, and as @Wreckless described above, is to go 295/35/18s in the rear. See below (went to 275/35s up front when I went with 295/35s out back but the point remains):

That fitment is sick! Did you have to pull, cut or roll the fenders? What are the specs on the rims?
 

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18 x 10 +46, front; 18 x 11 +48, rear.
275/35/18 front; 295/35/18, rear, MPSS tires

No pull, cut or roll on the front fenders. Very conservative cut in rear (spot welds still in place).

Thanks for the kind words.


Ken.
 

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18 x 10 +46, front; 18 x 11 +48, rear.
275/35/18 front; 295/35/18, rear, MPSS tires

No pull, cut or roll on the front fenders. Very conservative cut in rear (spot welds still in place).

Thanks for the kind words.


Ken.
Thanks you for the specs, any spacers used Ken?
 

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No spacers used. Just 10 and 11 inch wide wheels that are BBK-compatible and have the right offset. A lot of guys have gone 11.5 inch wheels out back. I could have done that, but I prefer a more neutral handling car.

@RikTT and @Radride have a MKIV-specific wheel/tire fitment thread on here, started by @RikTT in 2009. It is the best thread of its type bar none. If you have any wheel/tire fitment questions, post them up in that thread and those guys will lead you to paradise. Hope this helps.


Ken.
 

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So, thanks to this thread, I’ve got to look in to new tires myself. Bought my car in late Nov of 2020, said tires had less than a 1000 miles. Went down and looked, they are from 2006! 😳🤦🏼‍♂️
 

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So, thanks to this thread, I’ve got to look in to new tires myself. Bought my car in late Nov of 2020, said tires had less than a 1000 miles. Went down and looked, they are from 2006! 😳🤦🏼‍♂️
Remember, you're not allowed to replace the rear tires on a Supra until you throw down at least one bigass smoky burnout :)
 
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