[mdma-zn]

Upgraded rears to Toyo R888R 295/30/19 and decided to put the original rear tyres up front. My front tyres were touching when fully turning.
265 is just too wide... quite disappointing especially since the 265s looked full and really good!

I put the original 245/35/19s back on the front and will drive like this for a while. I have not noticed any adverse effects from the current 50mm width differential but then again i have not pushed my M2C hard enough yet...

R888R has so much more grip but be prepared for road noise! I knew this was going to be the case, when i opted for the Toyo's rather than the PS4S's.

[ZM2]

Too wide or too tall?

In my experience they rub until you’ve burned thru a cpl mm of the tire or fender liner.

[mdma-zn]

too wide.
Not sure if i spacer could help?

[ZM2]

What are you rubbing width wise? I’ve never had an issue with 265/35/19 width upfront, just height.

If you’re rubbing the fender, you can trim the tabs some to make room.

[Proctor750]

wait, you took the stock 788 rear wheel with pss and put on the front?

so 10" and ET40*

[ZM2]

Originally Posted by Proctor750

wait, you took the stock 788 rear wheel with pss and put on the front?

so 10" and ET40*

My head cold meds didn’t catch this.

Of course that won’t work! Doesn’t have anything to do with the tire.

[Expert@ApexWheels]

Sidewall height is the issue with a 265/35-19. It's 14mm taller than the OEM 245/35-19 tires, which causes it to scrub the fender liner during full-lock turns.

265/30-19 is the way to go up front, which is what we use with our 19x9.5" ET28 wheels. Fits perfectly and plenty of room to spare between the tire and fender liner.



--Dylan

[mdma-zn]

Originally Posted by Proctor750

wait, you took the stock 788 rear wheel with pss and put on the front?

so 10" and ET40*

No no...

I put the stock rear tyres on my front 19'' 9Jx19ET:29 763 RIMS.

[mdma-zn]

Originally Posted by Expert@ApexRaceParts

Sidewall height is the issue with a 265/35-19. It's 14mm taller than the OEM 245/35-19 tires, which causes it to scrub the fender liner during full-lock turns.

265/30-19 is the way to go up front, which is what we use with our 19x9.5" ET28 wheels. Fits perfectly and plenty of room to spare between the tire and fender liner.

--Dylan

Thank you Dylan.
Please help me understand why the same profile tyres will have a different height.... both original and attempted replacement have a 35 profile.

I did not see where it was touching and could only feel it during steering lock. I reduced the tyre pressure to 30 PSI to see if it would help but this did not work. Because it only occured during a full turn, I interpreted this as a width issue....

[ZM2]

The 265/35 rubs bc it’s a taller tire. Once you wear the tire and fender liner a few mm, it fits without rubbing.

That said a 265 on a 9” rim creates lazy turn in, and the 265 on our cars is meant to be a rear tire and has less channels for rain dispersion.

So, the widest/tallest I’d go on the stock front rims is 255/35/19. A little less lateral grip, but it doesn’t rub, hydroplanes less, and turn in is sharper.

[tux2005]

Originally Posted by mdma-zn

Thank you Dylan.
Please help me understand why the same profile tyres will have a different height.... both original and attempted replacement have a 35 profile.

I did not see where it was touching and could only feel it during steering lock. I reduced the tyre pressure to 30 PSI to see if it would help but this did not work. Because it only occured during a full turn, I interpreted this as a width issue....

Tire profiles are a ratio of the tread width, a 35 profile tire is 35% of the width of the tire, so a 35% of a 245/35R19 is 85.75mm of sidewall height while 35% of 265/35R19 is 92.75mm. The ratio is based on the tread width, not the rim size.

(Keep in mind that the tread widths and profiles are not actually exact, certain tires will run wider or narrower than the written spec)

[Expert@ApexWheels]

Originally Posted by mdma-zn

Thank you Dylan.
Please help me understand why the same profile tyres will have a different height.... both original and attempted replacement have a 35 profile.

I did not see where it was touching and could only feel it during steering lock. I reduced the tyre pressure to 30 PSI to see if it would help but this did not work. Because it only occured during a full turn, I interpreted this as a width issue....

See below!

Originally Posted by tux2005

Tire profiles are a ratio of the tread width, a 35 profile tire is 35% of the width of the tire, so a 35% of a 245/35R19 is 85.75mm of sidewall height while 35% of 265/35R19 is 92.75mm. The ratio is based on the tread width, not the rim size.

(Keep in mind that the tread widths and profiles are not actually exact, certain tires will run wider or narrower than the written spec)

^ This is correct. The sidewall aspect ratio or "35" number is often mistaken to be a fixed value. This makes tire sizes just a little more confusing, especially when trying to find wider tires that maintain the correct OEM rolling diameter.

The M2 has somewhat limited clearance in the front fender wells, so they are sensitive to using increased rolling diameters, and you'll experience the rubbing described in the OP. As mentioned, sometimes it goes away on its own after a few hundred miles, but not always. It really depends on how much larger than stock the tires are.

OEM rolling diameters:
Front 245/35-19 - 25.8"
Rear 265/35-19 - 26.3"

Performance Street/Track tire size rolling diameters that we run on our M2C-specific wheels:
Front 265/30-19 - 25.3"
Rear 285/30-19 - 25.7"

https://tiresize.com/comparison/ <-- This website is a great tool that helps visualize how different sizes compare to each other.

--Dylan

[Proctor750]

Originally Posted by Expert@ApexRaceParts

See below!



^ This is correct. The sidewall aspect ratio or "35" number is often mistaken to be a fixed value. This makes tire sizes just a little more confusing, especially when trying to find wider tires that maintain the correct OEM rolling diameter.

The M2 has somewhat limited clearance in the front fender wells, so they are sensitive to using increased rolling diameters, and you'll experience the rubbing described in the OP. As mentioned, sometimes it goes away on its own after a few hundred miles, but not always. It really depends on how much larger than stock the tires are.

OEM rolling diameters:
Front 245/35-19 - 25.8"
Rear 265/35-19 - 26.3"

Performance Street/Track tire size rolling diameters that we run on our M2C-specific wheels:
Front 265/30-19 - 25.3"
Rear 285/30-19 - 25.7"

https://tiresize.com/comparison/ <-- This website is a great tool that helps visualize how different sizes compare to each other.

--Dylan

Which means for those like me who primarily use RS4's or RE-71R tires;

Hankook doesn't make a 30 series RS4 which fits the front and the 275 35 series tire as pointed out by ZM2 is too tall.

Which leaves the RE-71R.
The rear is fine you can go 285/35 or 305/30 (the 305 is actually shorter, not that it matters back there)

The front... 255 or 265 and only 35 series for either. Those on stock wheels can do 255/285 and it will probably work out great.

I got the EC7's for more meat and the 255 are too stretched on the 9.5 up front so I will go 265 and to hell with the fender liner.

Hopefully more tire manufacturers will begin throwing the 19 crowd a bone. It's amazing I experience this on both ends of the spectrum with the E30 15" hardly any tire choices in the sizes we want and 15x9's are unobtanium or not ready etc etc. but I digress.




(first image is RS4 sizes, second is RE-71R)

[ZM2]

Originally Posted by Proctor750

Which means for those like me who primarily use RS4's or RE-71R tires;

Hankook doesn't make a 30 series RS4 which fits and the 275 35 series tire as pointed out by ZM2 is too tall.

Which leaves the RE-71R.
The rear is fine you can go 285/35 or 305/30 (the 305 is actually shorter, not that it matters back there)

The front... 255 or 265 and only 35 series for either. Those on stock wheels can do 255/285 and it will probably work out great.

I got the EC7's for more meat and the 255 are too stretched on the 9.5 up front so I will go 265 and to hell with the fender liner.

Hopefully more tire manufacturers will begin throwing the 19 crowd a bone. It's amazing I experience this on both ends of the spectrum with the E30 15" hardly any tire choices in the sizes we want and 15x9's are unobtanium or not ready etc etc. but I digress.




(first image is RS4 sizes, second is RE-71R)

Yeah, the only decent 265/295/30 track tires are the R888R and Trofeo R. Both are slower than the 71R with similar longevity.

I thought the Trofeo R was pretty impressive as a summer, grippy street tire, tho. Pretty comfortable & quiet. It’s just expensive, lasts 1/3 as long as the 4S, isn’t good in the wet or cold, and is slower than the 71R on track. Too many compromises...

Maybe we’ll get an RS4 in the right size someday.

[CSBM5]

Originally Posted by Proctor750

I got the EC7's for more meat and the 255 are too stretched on the 9.5 up front so I will go 265 and to hell with the fender liner.

I have 9.5 with 255/35-19 up front on my E90 M3 (Apex EC7), and I don't view those as too stretched (PS4S). It looks just right aesthetically, but more importantly, the tire feels great in transient response. On the rear I'm using 275/35-19 with 10.5. Both ends feel nice, taught and responsive.

Personal preference, but I'd just stick with the 255/35s and save the liner and tire from issues.

[wanofakind01]

Originally Posted by Proctor750

Which means for those like me who primarily use RS4's or RE-71R tires;

Hankook doesn't make a 30 series RS4 which fits the front and the 275 35 series tire as pointed out by ZM2 is too tall.

Which leaves the RE-71R.
The rear is fine you can go 285/35 or 305/30 (the 305 is actually shorter, not that it matters back there)

The front... 255 or 265 and only 35 series for either. Those on stock wheels can do 255/285 and it will probably work out great.

I got the EC7's for more meat and the 255 are too stretched on the 9.5 up front so I will go 265 and to hell with the fender liner.

Hopefully more tire manufacturers will begin throwing the 19 crowd a bone. It's amazing I experience this on both ends of the spectrum with the E30 15" hardly any tire choices in the sizes we want and 15x9's are unobtanium or not ready etc etc. but I digress.




(first image is RS4 sizes, second is RE-71R)

Are you running a square set of EC-7 or a wider tire in the rear?

[Proctor750]

Originally Posted by wanofakind01

Are you running a square set of EC-7 or a wider tire in the rear?

I would prefer to run square where possible but on track the M2 with S55 (especially if tuned) needs more help in the rear than can fit in the front.
So staggered 19x9.5 et28 front EC7 and 19x10.5 et45 rear EC7.

The plan was to run a 265 front and 285 rear (re71r) to start things off.
The desire was to run 30 series RS4's which don't exist.

I may start dropping off letters at the hankook headquarters here. What's odd is they don't sponsor motorsport - it's some 3rd party guy in Miami and he only works with their R compound stuff. There is no support or sponsorship potential for arguably one of the best performance street tires ever made (imo).

[wanofakind01]

Originally Posted by Proctor750

I would prefer to run square where possible but on track the M2 with S55 (especially if tuned) needs more help in the rear than can fit in the front.
So staggered 19x9.5 et28 front EC7 and 19x10.5 et45 rear EC7.

The plan was to run a 265 front and 285 rear (re71r) to start things off.
The desire was to run 30 series RS4's which don't exist.

I may start dropping off letters at the hankook headquarters here. What's odd is they don't sponsor motorsport - it's some 3rd party guy in Miami and he only works with their R compound stuff. There is no support or sponsorship potential for arguably one of the best performance street tires ever made (imo).

Ahhhh ok you're going with the 19" set, got excited for a sec thinking the 18" finally came out with a 10.5 ET 40 or 45

[Proctor750]

Originally Posted by wanofakind01

Ahhhh ok you're going with the 19" set, got excited for a sec thinking the 18" finally came out with a 10.5 ET 40 or 45

yeah, gotta clear the truck brakes

didn't mean to get the hopes up

[JTO24]

Originally Posted by CSBM5

I have 9.5 with 255/35-19 up front on my E90 M3 (Apex EC7), and I don't view those as too stretched (PS4S). It looks just right aesthetically, but more importantly, the tire feels great in transient response. On the rear I'm using 275/35-19 with 10.5. Both ends feel nice, taught and responsive.

Personal preference, but I'd just stick with the 255/35s and save the liner and tire from issues.

Off-topic but wow I love your E90 M3! Slicktop SS is perfect

[mdma-zn]

An update:
I have been running with the Toyo R888Rs 295/30/19 in the rear and the oem 245/35/19 in the front.

The stability of my car is aweful. 50mm diff between front and back is clearly a dont-do-it mod. Im loving the Toyos in the back and putting the power down nicely with my BM3 tune.

In this interim I am going fast in straight lines only. I am not sure if 255/45/19 will improve things significantly. I may have no choice but to go 265/30/19.

[ZM2]

Yeah, you should run 265/30 up front if you’re 295/30 in the rear. I’ve run that combo in a couple different tires and the balance is good.