[hjl113]

Hi guys.

I have winter tires on (275/35/20 square set up) now but will be putting back UHP tires in spring.

My back tire (285/35/20 Pirelli Pzero OEM) has a lot of meat left in them so here is my dilema.

Put the 285/35/20 in front wheel (9.5j) and put 295/35/20 PS4S in the back (10.5j)

It seems 10.5j can take the 295 no problem, but putting 285/35/20 seem it's pushing the limit on the 9.5j OEM wheel.


Has anyone done 285/35/20 and 295/35/20 on the OEM wheels?
They are about +0.7% difference, so tolerance should be ok, but my concern is putting the 285/35/20 on the 9.5j OEM wheel.

I don't want to have unstable during high speed cornering.

Please let me (and the people on the forum) know if this setup is ok even with spirited driving.

Thank you guys.

[bcparker2]

I've been on 285/295 for 15k miles no issues with the 706m wheels.

[shawnhayes]

Pirelli says that this is okay on a 9.5.

I have put 285/35 on all four wheels and wrung it completely out on the track for many sessions. You will be fine.

Shawn

[luke1990]

Originally Posted by hjl113

Hi guys.

I have winter tires on (275/35/20 square set up) now but will be putting back UHP tires in spring.

My back tire (285/35/20 Pirelli Pzero OEM) has a lot of meat left in them so here is my dilema.

Put the 285/35/20 in front wheel (9.5j) and put 295/35/20 PS4S in the back (10.5j)

It seems 10.5j can take the 295 no problem, but putting 285/35/20 seem it's pushing the limit on the 9.5j OEM wheel.


Has anyone done 285/35/20 and 295/35/20 on the OEM wheels?
They are about +0.7% difference, so tolerance should be ok, but my concern is putting the 285/35/20 on the 9.5j OEM wheel.

I don't want to have unstable during high speed cornering.

Please let me (and the people on the forum) know if this setup is ok even with spirited driving.

Thank you guys.

Are you running 275/35/20 square on stock 9.5/10.5 20inch rims? I just got the car and need winters - but there is no good 285/35 tire so thinking of putting 275 square on the stock wheels if possible. Thanks a lot!

[hjl113]

Originally Posted by luke1990

Are you running 275/35/20 square on stock 9.5/10.5 20inch rims? I just got the car and need winters - but there is no good 285/35 tire so thinking of putting 275 square on the stock wheels if possible. Thanks a lot!

Yes, I'm running 275/35 square now.
No problems so far.

[hjl113]

Originally Posted by shawnhayes

Pirelli says that this is okay on a 9.5.

I have put 285/35 on all four wheels and wrung it completely out on the track for many sessions. You will be fine.

Shawn

285/35 on the 9.5j stock wheel?
If this is really ok, I plan to put 285/35 in front and 295/35 in the rear for the spring.

[shawnhayes]

Originally Posted by hjl113

285/35 on the 9.5j stock wheel?
If this is really ok, I plan to put 285/35 in front and 295/35 in the rear for the spring.

285/35 on the stock front is just fine. I have run it. Manufacturer spec approves:

https://www.tirerack.com/tires/tires...XLV2&tab=Sizes

Running 285/35 square reduces the understeer A LITTLE. Not sure I'd recommend this for novices, but certainly possible.

I know little about your proposed setup. I hate non-square setups. Too much brain and worrying.

Shawn

[Boiler Up!]

No issues with running a 285 up front. In fact this is what you’ll find on the M5s at BMWs driving schools. They run their cars with 285 Contis front and rear.

[tripleog]

Literally just got a M5 Comp and came on this forum to find out the answer to this question. Thank you everyone. Great info and people.

[shawnhayes]

Originally Posted by Boiler Up!

No issues with running a 285 up front. In fact this is what you’ll find on the M5s at BMWs driving schools. They run their cars with 285 Contis front and rear.

Glad to know they came up with the same conclusion.

Shawn

[FSHNGRY]

My exact set up. Kinda. I did go into some detail on one of my most recent upgrades to my suspension set up.

IN A NUT SHELL, and based on what I have learned while owning and modding a car with this much power and torque, is that tires a smidge larger than what comes stock on the car ( and no, i'm not talking trash - I have the same set up as you'll see below! ) will NOT fix your issue regarding stability under hard acceleration and hard braking. Basically your rear tension links are "flexing" during these periods which will cause that feeling of instability you seek to fix. It pissed me off for some while and then I was given the knowledge here about a couple of parts that are PROVEN to give your F90 M5 a NIGHT and DAY difference... I can vouch, I did it to my car and it is F-in Perfect.

The 2 mods you are in search are linked here:

https://ind-distribution.com/collect...ball-joint-kit

https://ind-distribution.com/collect...nsion-link-kit

My Suspension/Tire Set up

20" 789M Wheels
Michelins:
Front: 285 | 35 | 20
Rear: 295 | 35 | 20
KW H.A.S Kit
Macht Schell 15mm Spacers (Front)
Future Classic 12mm Spacers (Rear)
Dinan Rear Tension Link Kit
Carbahn Ball Joint Kit
Future Classic 80mm Titanium Stud kit
Front:



Rear:



Fitment:

[hjl113]

Originally Posted by FSHNGRY

My exact set up. Kinda. I did go into some detail on one of my most recent upgrades to my suspension set up.

IN A SHUT SHELL, and based on what I have learned while owning and modding a car with this much power and torque, is that tires a smidge larger than what comes stock on the car ( and no, i'm not talking trash - I have the same set up as you'll see below! ) will NOT fix your issue regarding stability under hard acceleration and hard braking. Basically your rear tension links are "flexing" during these periods which will cause that feeling of instability you seek to fix. It pissed me off for some while and then I was given the knowledge here about a couple of parts that are PROVEN to give your F90 M5 a NIGHT and DAY difference... I can vouch, I did it to my car and it is F-in Perfect.

The 2 mods you are in search are linked here:

https://ind-distribution.com/collect...ball-joint-kit

https://ind-distribution.com/collect...nsion-link-kit

My Suspension/Tire Set up

20" 789M Wheels
Michelins:
Front: 285 | 35 | 20
Rear: 295 | 35 | 20
KW H.A.S Kit
Macht Schell 15mm Spacers (Front)
Future Classic 12mm Spacers (Rear)
Dinan Rear Tension Link Kit
Carbahn Ball Joint Kit
Future Classic 80mm Titanium Stud kit
Front:

Attachment 2774159

Rear:

Attachment 2774160

Fitment:
Attachment 2774161

Beautiful!

[FSHNGRY]

Originally Posted by hjl113

Beautiful!

thank you! I was just commenting on another thread about your car and the tyres!

I would love to go 305/35/20 in the rear and leave the 285/35/20 in the front on the 789Ms

Does it work? any issues?