r3 what tyres, 235/40/19 or 245/40/19 plus brand?

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r3 what tyres, 235/40/19 or 245/40/19 plus brand?

Post by Finalboss »

Looking at buying tyres for my r3 and looking at either michelin pilot sport 4s or goodyear eagle f1s if anyone has any experience with these, for road and a few track days a year.
Also considering what tyres to go for, the oem size 225/40/19 are far more expensive than a 235 or 245 so I will be going for one of these instead, what is the general consensus on tyre size?
Thanks!
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Re: r3 what tyres, 235/40/19 or 245/40/19 plus brand?

Post by Shagrington »

I know on the S1 we can safely use 235/40/18 and 245/40/18 instead of the standard 225/45/18 without going too far from the original rolling radius and the 235 and 245, as well as being a little wider so looking a little better are also cheaper to buy.

I'd guess you can do the same on the R3, but with the 19 inch wheels I'm not sure on what profile would work with the wider tyres. Try this "handy tool" to see what works (I think the idea is to not go much more than 1% difference in the overall rolling radius) https://www.tyresave.co.uk/tyre-size-calculator/
I found the link in the FAQ Section here viewtopic.php?f=25&t=35714
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Re: r3 what tyres, 235/40/19 or 245/40/19 plus brand?

Post by kopite72 »

I'm running 245/35 on my R3, vredestein Vorti tyres, zero complaints, great tyre
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Re: r3 what tyres, 235/40/19 or 245/40/19 plus brand?

Post by V8 Power »

I went for 245/35 on our R3 as well
Avon ZZ5’s which seem very good in dry and wet.
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Re: r3 what tyres, 235/40/19 or 245/40/19 plus brand?

Post by Leck3000 »

I have 235/35/19 on mine. I had full eagle f1’s and they’re good in the dry but not so good in the wet. Just put a pair of the Michelin pilot sport 4s on the rear and so much more wet grip.
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Re: r3 what tyres, 235/40/19 or 245/40/19 plus brand?

Post by New Duke »

I've usually used different logic and gone for slightly cheaper tyres but fitted the correct size. Sizing does make a measurable difference, you just won't necessarily notice it.

Nigel and I have used the Kumho KU39 for years both on road and frequent track and think they're excellent. Much better than many more expensive tyres.

Tyres are subjective, but paying lots more for Goodyears or Michelins won't make them perform noticeably better. Especially if you play with sizing.

New tyres will always have better wet grip than the old ones you took off... because treadwear. So a lot of this is in our heads and 'butt dyno' territory, unless measured by back to back laptimes.
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Re: r3 what tyres, 235/40/19 or 245/40/19 plus brand?

Post by Finalboss »

New Duke wrote:
Sat Jan 18, 2020 10:07 am
I've usually used different logic and gone for slightly cheaper tyres but fitted the correct size. Sizing does make a measurable difference, you just won't necessarily notice it.

Nigel and I have used the Kumho KU39 for years both on road and frequent track and think they're excellent. Much better than many more expensive tyres.

Tyres are subjective, but paying lots more for Goodyears or Michelins won't make them perform noticeably better. Especially if you play with sizing.

New tyres will always have better wet grip than the old ones you took off... because treadwear. So a lot of this is in our heads and 'butt dyno' territory, unless measured by back to back laptimes.

Have you tried michelin 4s?
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Re: r3 what tyres, 235/40/19 or 245/40/19 plus brand?

Post by MARKTHOMASBRAND »

I have a full set of Michelin Pilot Sport 4S :D

They are not fitted to an R3 though :p

I picked them over Continental Sport Contact 6 because they're better in the cold/wet & last waaaaaaaaaaay longer :thumleft:
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Re: r3 what tyres, 235/40/19 or 245/40/19 plus brand?

Post by delta0 »

I would suggest going 235/35 rather than 235/40. The diameter of the tyre will be higher than 225/40 if you use 235/40. I’m changing tyres this year and will be going 235/35. Goodyear brought out some new high performance tyres recently. I’m waiting to see what comes out from Continental etc.
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Re: r3 what tyres, 235/40/19 or 245/40/19 plus brand?

Post by Finalboss »

delta0 wrote:
Sat Jan 18, 2020 6:27 pm
I would suggest going 235/35 rather than 235/40. The diameter of the tyre will be higher than 225/40 if you use 235/40. I’m changing tyres this year and will be going 235/35. Goodyear brought out some new high performance tyres recently. I’m waiting to see what comes out from Continental etc.
I thought the same but actually going by this site
https://www.tyresave.co.uk/tyre-size-calculator/
235/40 is 1.21% of a difference and 235/35 is -2.41% of a difference.
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Re: r3 what tyres, 235/40/19 or 245/40/19 plus brand?

Post by delta0 »

Finalboss wrote:
Sat Jan 18, 2020 6:49 pm
delta0 wrote:
Sat Jan 18, 2020 6:27 pm
I would suggest going 235/35 rather than 235/40. The diameter of the tyre will be higher than 225/40 if you use 235/40. I’m changing tyres this year and will be going 235/35. Goodyear brought out some new high performance tyres recently. I’m waiting to see what comes out from Continental etc.
I thought the same but actually going by this site
https://www.tyresave.co.uk/tyre-size-calculator/
235/40 is 1.21% of a difference and 235/35 is -2.41% of a difference.
One way to gain a tiny bit on the acceleration and the other your speedo under reads slightly. It is only slight either way but I would take everything I could get. The mass of the tyre should be less as well at 235/35 vs 235/40
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Re: r3 what tyres, 235/40/19 or 245/40/19 plus brand?

Post by Finalboss »

im just thinking the slightly bigger tyre would protect the wheels from bending if I hit pot holes etc
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Re: r3 what tyres, 235/40/19 or 245/40/19 plus brand?

Post by Conan »

I don’t recommend the 35 profile to anyone in 18 or 19 wheels
It’s important to have some movement and give in the tyre wall for handling and soaking up the potholes we have in GB
The exception would be of course if you had ridiculously wide tyres like 300mm and then 35% would give you decent tyre wall hight.
Go for the 235x40 option which I assume fit fine, plenty of R-3 owners to confirm here.
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Finalboss (Sat Jan 18, 2020 7:39 pm)
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Re: r3 what tyres, 235/40/19 or 245/40/19 plus brand?

Post by Finalboss »

Conan wrote:
Sat Jan 18, 2020 7:38 pm
I don’t recommend the 35 profile to anyone in 18 or 19 wheels
It’s important to have some movement and give in the tyre wall for handling and soaking up the potholes we have in GB
The exception would be of course if you had ridiculously wide tyres like 300mm and then 35% would give you decent tyre wall hight.
Go for the 235x40 option which I assume fit fine, plenty of R-3 owners to confirm here.
Regards
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Re: r3 what tyres, 235/40/19 or 245/40/19 plus brand?

Post by Conan »

Your logic is correct :thumleft:
I have an S-1 not an R-3 so don’t know how the 245x40 fits in the arch
However a discerning driver would feel the difference with the higher gearing slowing acceleration and vaguer turn in.
I advise 235 as the best compromise for handling and straight line drag.
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Re: r3 what tyres, 235/40/19 or 245/40/19 plus brand?

Post by New Duke »

Finalboss wrote:
Sat Jan 18, 2020 10:54 am
New Duke wrote:
Sat Jan 18, 2020 10:07 am
I've usually used different logic and gone for slightly cheaper tyres but fitted the correct size. Sizing does make a measurable difference, you just won't necessarily notice it.

Nigel and I have used the Kumho KU39 for years both on road and frequent track and think they're excellent. Much better than many more expensive tyres.

Tyres are subjective, but paying lots more for Goodyears or Michelins won't make them perform noticeably better. Especially if you play with sizing.

New tyres will always have better wet grip than the old ones you took off... because treadwear. So a lot of this is in our heads and 'butt dyno' territory, unless measured by back to back laptimes.

Have you tried michelin 4s?
Yes. But not on the RX8.
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Re: r3 what tyres, 235/40/19 or 245/40/19 plus brand?

Post by 350matt »

Another vote for 235/40 R18 here
I switched from the stock size to this in a uniroyal rainsport and yes its considerably cheaper but the smaller diameter helps acceleration ( small but you do feel it) and the extra rubber width helps grip and the lower sidewall improves steering feel

the only downside is a slightly worse ride
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Re: r3 what tyres, 235/40/19 or 245/40/19 plus brand?

Post by Conan »

That’s all perfectly true on the S-1 Matt when you change from 225x45x18 to 235x40x18
The OP has a R-3 so goes from 225x40x19 to 235x40x19 so increases the hight of the sidewall slightly.
Still the way to go though
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Re: r3 what tyres, 235/40/19 or 245/40/19 plus brand?

Post by WildMan10 »

I’ve done a fair few R3 miles on non-standard width tyres, all from wheels I inherited. I recently fitted 225/40/19 4s tyres all round as I much prefer the standard width because I didn’t like the wider ones’ effect on steering, making it heavier and prone to tram-lining.

I’m currently running 225/45/18 Cross Climates on 40th Ann alloys. I much prefer feel over the 235/40/18 I had on before.

All that is personal preference. Perhaps I’m getting too old . . .
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Re: r3 what tyres, 235/40/19 or 245/40/19 plus brand?

Post by Techathy »

New Duke wrote:
Sat Jan 18, 2020 8:27 pm
Finalboss wrote:
Sat Jan 18, 2020 10:54 am
New Duke wrote:
Sat Jan 18, 2020 10:07 am
I've usually used different logic and gone for slightly cheaper tyres but fitted the correct size. Sizing does make a measurable difference, you just won't necessarily notice it.

Nigel and I have used the Kumho KU39 for years both on road and frequent track and think they're excellent. Much better than many more expensive tyres.

Tyres are subjective, but paying lots more for Goodyears or Michelins won't make them perform noticeably better. Especially if you play with sizing.

New tyres will always have better wet grip than the old ones you took off... because treadwear. So a lot of this is in our heads and 'butt dyno' territory, unless measured by back to back laptimes.

Have you tried michelin 4s?
Yes. But not on the RX8.
I totally agree with you on the KU39 (I was glad when I saw KU39 on all 4 corners of my RX-8), it's a really good tyre and is up there for the best bang per-buck tyre on the market. However, I find that the Pilot 4 (not the 4S) has a more consistent, but not necessarily higher, grip level across the wide-ranging conditions in daily driving.

This is experience from my a BMW Z4 35iS and Lotus Evora I've not yet tried Pilot 4 tyres on my RX-8, so my opinion may change in due course.
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Re: r3 what tyres, 235/40/19 or 245/40/19 plus brand?

Post by RX8R3Rod »

I have 20” wheels on my R3, so this isn’t a perfect comparison, but I currently have pilot sport 4 s 245/30/20.

They are very good IME, and for what that’s worth, being a really nice compromise of softish ride, reasonable noise and good feel.

That said, I much preferred the Dunlop SP Sport Maxx I had on previously but (as Pete suggested earlier) because their sidewalls are not only super-small but super-stiff, the shoulders kept splitting (not the safest of things, I imagine 🤔) as they presumably over-flexed at that point because the sidewalls (such as they are 😄) didn’t or couldn’t flex much.

They made the car feel like it was absolutely glued to the road, and you could feel pretty-much everything that was going on ... almost like running your fingers over the road surface. Bliss.

Whenever Cheryl drove the car any distance she would say the same.

But the need to constantly check if your tyre is about to blow because of a break at the shoulder (and every time it was the inside shoulder, not the one you can see easily) isn’t the very best feeling longer term ... ☹️

Hence the Michelins, which so far have done rather better with their softer sidewalls.
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Re: r3 what tyres, 235/40/19 or 245/40/19 plus brand?

Post by *thomas* »

Recycling old(-ish) threads again, I'm sorry.

I'm having difficulties choosing the right tyre-size. I would like a set of BBS SR wheels for my car and I would like the wheels to sit more flush with the fender (I do not want them to stick out, neither do I want to roll the fenders).

The wheel I want comes in 3 sizes:

18*8 ET40
19*8,5 ET45 or ET35

I'm leaning towards the second option with a 245/35/19 tyre, but how does this compare to a 225/45/18. I've considered a 235/40/19, but - once more - the Belgian law does not allow this size on an rx8.
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Re: r3 what tyres, 235/40/19 or 245/40/19 plus brand?

Post by mi60o0 »

I have good year f1 asymmetric on my daily car. They seems superb I run 245 40 18.
And once I wear the Bridgestone on the rx8 I'm going to buy Eagle f1 for the rex to I manage to snap them at 80 per corner and my mate fitted them for me so no brainer
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Re: r3 what tyres, 235/40/19 or 245/40/19 plus brand?

Post by *thomas* »

mi60o0 wrote:
Thu Jul 09, 2020 11:59 pm
I have good year f1 asymmetric on my daily car. They seems superb I run 245 40 18.
And once I wear the Bridgestone on the rx8 I'm going to buy Eagle f1 for the rex to I manage to snap them at 80 per corner and my mate fitted them for me so no brainer
I see you have a 192BHP model (so do I), did you ever run it on stock size? Any difference in feel comparing 225 and 245?
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Re: r3 what tyres, 235/40/19 or 245/40/19 plus brand?

Post by mi60o0 »

The 245 I run on my daily s max that is tubed and need to dyno it etc after the new intercooler etc the 7 seater will be runing 300 bhp mark.
My rx8 I run 245 atm but I prefer 235 40 18. Also for standard car I don't see much of a difference 192 and 231
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