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[bb_00]

I'm curious what are the pros and cons of running 245/35/19 vs 255/35/19 for the fronts.

[layzie]

What size wheel and what kind of tire? I have Bridgestone s04 pole positions in 255/35/19 on a 19x9 et17.5 wheel in the front with no issues. I like the meaty look with more tire contact on the road. I know some tires like Michelin will run bigger in the same size and have rubbing issues.

[bb_00]

Michelin PS4S on 19" 220M.

I think I heard somewhere that 255 will not have the crisp turn-in as the 245.

[TrAcK TRaP]

You'll be fine with 275/35/19 on rear also..

[layzie]

Id go with a 245 on a 220m. I don't know if i would run a 255 on a 8.5, especially a Michelin. Youll rub the inner fender wells when turning. Running a 255 on a 8.5 will give you more of a squishy feel, which is why people may have said its not as crisp. I wouldn't run a 255 on anything less than 9''

[ApexWheels]

What tire size are you going to run in the rear? This will help dictate what you run up front.

By running wider tires up front and reducing the delta from front to rear, you are effectively reducing the cars natural tendency to understeer or "push" through the corners. This is advantageous for enthusiasts taking the car to the canyons, or HPDE's which is why square fitments are so popular. If your plan is to increase the front and rear tire cohesively by one size (+1 sizing) then you will not impact the cars tendency to understeer much.

More front end grip = better turn-in. Slimmer tires up front will give off a lighter steering feel, while with wider front tires steering will feel a little heavier.

You do not want to over tire a wheel, or you will experience more sidewall flex in mid-corner. That can be described as mushy feeling. Stiff sidewalls are typically desired, and that comes from proper sidewall support from a wheel width that is wide enough to support the tire in question.

It is simply a trade off. The wider tires (255 / 275) will provide you with more grip when traveling in a straight line, however will have more sidewall flex in mid corner. The OEM sizes (245 / 265) will have slightly less grip in a straight line, however they will have less sidewall flex and better handling characteristics in mid-corner.

This is getting overly technical for most street oriented customers, and both combinations will safely mount to the OEM 220's. For Michelin PS4's which run decently wide in the street tire category, I would opt for the 245 / 265 combo if I was outfitting the OEM 220's. With the ZCP 9" front / 10" rear setup, I jump up to 255 / 275.

- Ryan

[CSBM5]

Originally Posted by layzie

Id go with a 245 on a 220m. I don't know if i would run a 255 on a 8.5, especially a Michelin. Youll rub the inner fender wells when turning. Running a 255 on a 8.5 will give you more of a squishy feel, which is why people may have said its not as crisp. I wouldn't run a 255 on anything less than 9''

255/35 on an 8.5" wheel is a common factory fitment across numerous car lines (i.e. like every sport package E90 330i/335i, E46 ZHP, Mercedes, etc, etc).

Similarly, a 275/35 on a 9.5" wheel is a profoundly common factory fitment also such as the E39 M5.

There is zero rubbing with a 255/35 up front on the OEM 220M wheel. I've run the 255/275 combo in PSS now for over 4 years with zero issue. For the most part, you're gaining nothing for street use other than paying a tad more and maybe tad better curb protection.

I'd also go with the factory sizes for the PS4S as Ryan suggests.

[bb_00]

Appreciate for the in depth explanation, Ryan. I'm actually into the technicality.

What if running 245/35/19 front and 275/35/19 rear on 220M? What effect will that have?

Will it be best of both world where we can achieve better straight line grip and less tire wall flex?

[dparm]

Honestly, I would tell you to run 255/275 from a practical standpoint alone.

1. many more tire choices
2. typically cheaper than 245/265 combo
3. gives you a hair more sidewall which means better wheel protection & ride comfort

Subjectively, I would say it looks better too -- the 10mm in extra width fills out the wheel wells better and makes the tires look less stretched.

I don't think you will notice a huge difference in handling with 255/275 over the stock 245/265 unless you are tracking and autocrossing routinely.

[MJBO]

Not finding the firm answer I’ve been searching for.

Are people running Michelin Pilot Sport 4 S (PS4S) 255/35/19 and 275/35/19 on completely stock E90 M3 with 220M wheels without issue?

I’m about to order tyres and would love the slightly meatier look, but only if it’s not going to cause issues.

[CSBM5]

Originally Posted by MJBO

Not finding the firm answer I’ve been searching for.

Are people running Michelin Pilot Sport 4 S (PS4S) 255/35/19 and 275/35/19 on completely stock E90 M3 with 220M wheels without issue?

I’m about to order tyres and would love the slightly meatier look, but only if it’s not going to cause issues.

I ran the 255/35-19 and 275/35-19 Pilot Super Sports for 4+ years on 220Ms with zero issues. Currently have the PS4S in same sizes but on 9.5 and 10.5 Apex EC-7 wheels with no issues of any kind either.

[sibhusz06]

Actually im probably one of the few against a wider tire in the front, Although I have the comp wheels, im sticking with the oem size as im sure BMW sized this cars tires for the street correctly.

It increases tramlining and tire scrub radius changes. The car won't turn is as quick and it won't feel as crisp. Also I've noticed the 255s are almost 3-5lbs heavier than their 245 counterparts and thus increases unsprung weight as well as rolling resistance. On a street car, you'll notice 5lbs as the car will tend to crash more over bumps.

[CSBM5]

Originally Posted by sibhusz06

Actually im probably one of the few against a wider tire in the front, Although I have the comp wheels, im sticking with the oem size as im sure BMW sized this cars tires for the street correctly.

It increases tramlining and tire scrub radius changes. The car won't turn is as quick and it won't feel as crisp. Also I've noticed the 255s are almost 3-5lbs heavier than their 245 counterparts and thus increases unsprung weight as well as rolling resistance. On a street car, you'll notice 5lbs as the car will tend to crash more over bumps.

The PS4S 255/35-19 is less than 1lb heavier than the 245/35. To gain 5lbs in tire weight, you would need to go to a 295/30-19.

If one is really concerned with unsprung weight and rotational inertia, the 359M wheels are the place to start. You just about can't find heavier wheels for their size. Apex EC-7s are 0.5" wider at each end and are 4lbs per wheel lighter than the 359M.

Scrub radius is not a function of tire width. Wheel offset is the major player in changing scrub radius while tire diameter plays a very minor roll given how little it changes from a 245/35 to a 255/35. My Apex EC-7 front wheels are 9.5" wide and ET 22, so I changed the offset by 7mm; however, I experience zero tramlining. The minor increase in tire diameter slightly reduces scrub radius while the 7mm offset change increases it -- the net is that this minor overall change slightly increased scrub radius, so it in fact made the car feel more responsive on turn-in as turning moment forces are slightly larger with an increased scrub radius.

[Dave07997S]

You didn't say which wheel you are running. On the 220s I would keep the OEM sizes. With the ZCP wheels I would go with a 255/275 setup or 285s out back.

The larger front tire really does help this car. The E9X cars aren't light weight and a 245 up front is a joke. I now run 275/295 setup with 10" front and 11" rears and the car should have come from the factory this way. Turn in, over all grip out of the front of the car almost feels unflappable.

[MJBO]

Originally Posted by Dave07997S

On the 220s I would keep the OEM sizes.

Is that due to scrubbing issues?

[kyrix1st]

My street setup handled great with 255/265 PSS on LA220s. Much less understeer.