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[geneatals]

Originally Posted by M3/4 life

I was at the dealership today getting my MPE & BMC air filter installed and inquired about running a wider tire in the front & rear 255/35/19 f 275/35/19 r and the service advisor informed me that it could interfer with your traction control. (throwing codes & what not) For all of you with wider tires, has anyone had any issues with there traction control?

running this tire combo with 10mm rear and 12.5mm spacers in the front..no traction control issues....

[pkimM3r]

Originally Posted by M3/4 life

? I'm not sure I follow you ..... 245/35/19 is what my car came with up front stock & that's what I'm staying with however I'm going from 265/35/19 in the rear to 275/35/19. The person who was talking about the car being less crisp was running 255/35/19 f. And what does a supercharger have to do with it? Most people do it for looks, for it gives the car a more aggressive stance.

You got it wrong. Function over form. Always!!

[M3/4 life]

Originally Posted by pkim1079

You got it wrong. Function over form. Always!!

[pkimM3r]

Originally Posted by M3/4 life

Ok form over function. HeRRafrush!

[///M Ryder]

No codes on my end and I'm running 265-30 f and 295-30 r. As for why.......'cause I can. It's hard to notice any of what is being said as far as turn in and all that other crap on the street. On the track it's a different story.....so get the tires you want..........Phil

[M3/4 life]

Originally Posted by ///M Ryder

No codes on my end and I'm running 265-30 f and 295-30 r. As for why.......'cause I can. It's hard to notice any of what is being said as far as turn in and all that other crap on the street. On the track it's a different story.....so get the tires you want..........Phil

Thanks for the input Phil, I keep hearing a lot of ruckus about the 30mm difference between rear & front I plan on running 245/35/19 f 275/35/19 r However, I see you also have a 30mm stagger (as does the infamous M3 GTS) does the stagger effect anything in your opinion?

Thanks

[///M Ryder]

Originally Posted by M3/4 life

Thanks for the input Phil, I keep hearing a lot of ruckus about the 30mm difference between rear & front I plan on running 245/35/19 f 275/35/19 r However, I see you also have a 30mm stagger (as does the infamous M3 GTS) does the stagger effect anything in your opinion?

Thanks

The only thing it effects is the way I drive now .......I have more fun trying to step the rear out for a dance or two..............Phil

[M3/4 life]

Originally Posted by ///M Ryder

The only thing it effects is the way I drive now .......I have more fun trying to step the rear out for a dance or two..............Phil

Gotcha!

[Longwong]

Originally Posted by M3/4 life

? I'm not sure I follow you ..... 245/35/19 is what my car came with up front stock & that's what I'm staying with however I'm going from 265/35/19 in the rear to 275/35/19. The person who was talking about the car being less crisp was running 255/35/19 f. And what does a supercharger have to do with it? Most people do it for looks, for it gives the car a more aggressive stance.

If you don't follow than probably no point in explaining as you likely will not care. But go check out the weight of the 275/35 tire compared to the 265/35. Every couple pounds of rotating mass in the tire is a big impact on acceleration, mileage and handling. Also if you are changing the relative diameter of the cars front and rear which you would if you ran 245's up front, than you upset the balance that the car was designed for when you are pushing the car as the differential will be slightly receiving different wheel speeds.

If you are doing it for looks which you are obviously that is fine. And what does a supercharger have to do with it? Its called needing more traction at which point some extra weight in the tires is easily made up for by the 150 extra power a supercharger has and the ability to put the power down instead of spinning is worth a few extra pounds on the tire

[slicer]

Originally Posted by Longwong

If you don't follow than probably no point in explaining as you likely will not care. But go check out the weight of the 275/35 tire compared to the 265/35. Every couple pounds of rotating mass in the tire is a big impact on acceleration, mileage and handling. Also if you are changing the relative diameter of the cars front and rear which you would if you ran 245's up front, than you upset the balance that the car was designed for when you are pushing the car as the differential will be slightly receiving different wheel speeds.

If you are doing it for looks which you are obviously that is fine. And what does a supercharger have to do with it? Its called needing more traction at which point some extra weight in the tires is easily made up for by the 150 extra power a supercharger has and the ability to put the power down instead of spinning is worth a few extra pounds on the tire

I agree that weight is certainly important but adding wider tires can positively impact more than just traction during acceleration. Wider tires can improve lateral grip; aka cornering. You can also dial out under steer by reducing front / rear stagger.

[M3/4 life]

Originally Posted by Longwong

If you don't follow than probably no point in explaining as you likely will not care. But go check out the weight of the 275/35 tire compared to the 265/35. Every couple pounds of rotating mass in the tire is a big impact on acceleration, mileage and handling. Also if you are changing the relative diameter of the cars front and rear which you would if you ran 245's up front, than you upset the balance that the car was designed for when you are pushing the car as the differential will be slightly receiving different wheel speeds.

If you are doing it for looks which you are obviously that is fine. And what does a supercharger have to do with it? Its called needing more traction at which point some extra weight in the tires is easily made up for by the 150 extra power a supercharger has and the ability to put the power down instead of spinning is worth a few extra pounds on the tire

I understand your point in a way....I guess. However the

M3 GTS 255/35/19 f 285/30/19
Cayman S 235/40/19 f 265/40/19 r
Mercedes SLS AMG GT 265/35/19 f 295/30/20 r
*(all have 30mm stagger)

to name a few: none of which are supercharged seem to have the same idea as I.....Just sayin

I mean if I tracked my car maybe I would understand how your point would apply. However, I don't my car is my dd I average maybe 4000 miles per year in her. I bought an M3 because it was/is my dream car. Not to track not to drag race but to drive and look good doing it! I could truly car less about some rotating mass and actually she should handle better going from a 265 to 275 in the rear. And 245 came stock on my car up front. Nevertheless thanks for the input!

[CSBM5]

Originally Posted by Longwong

If you don't follow than probably no point in explaining as you likely will not care. But go check out the weight of the 275/35 tire compared to the 265/35. Every couple pounds of rotating mass in the tire is a big impact on acceleration, mileage and handling. Also if you are changing the relative diameter of the cars front and rear which you would if you ran 245's up front, than you upset the balance that the car was designed for when you are pushing the car as the differential will be slightly receiving different wheel speeds.

If you are doing it for looks which you are obviously that is fine. And what does a supercharger have to do with it? Its called needing more traction at which point some extra weight in the tires is easily made up for by the 150 extra power a supercharger has and the ability to put the power down instead of spinning is worth a few extra pounds on the tire

Changing relative diameters between the front and rear, as when running a square setup, has absolutely NO effect on the differential (on the M3 or any other car). The only way to influence the diff of course, and hence the LSD, would be to have different tire diameters on one side versus the other.

Re tire weight. Changing to a 275/35 from a 265/35 will have an UNMEASURABLE effect on the car's acceleration due to the minor weight addition. It will be within the repeatability window of the data logging in acceleration tests. Also, since it only has an effect when there is acceleration of the wheel, AND since that effect drops of exponentially with speed (i.e. 1st gear has the highest acceleration rate, then accel rates fall successively as speeds climb), there will be zero effect on measured gas mileage that you can measure. At minor acceleration rates (essentially all of daily driving), it's trivial, and at a rather constant speed (cruising) there is ZERO contribution to minor effect of a small increase in rotational inertia.

[slicer]

Originally Posted by M3/4 life

I understand your point in a way....I guess. However the

M3 GTS 255/35/19 f 285/30/19
Cayman S 235/40/19 f 265/40/19 r
Mercedes SLS AMG GT 265/35/19 f 295/30/20 r
*(all have 30mm stagger)

to name a few: none of which are supercharged seem to have tnhe same idea as I.....Just sayin

The tire sizes on other cars is completely immaterial (aside from the M3 GTS). Your examples are comparing tire sizes on mid engined cars to a front engined M3 (SL'S is a front-mid engine as the motor sits behind the front wheels). The handling dynamics are completely different. Rear wheel traction is one component of tire sizing. Handling around corners is far more important. which gets back to my point about lateral grip.

[happos2]

I have 245/35/19 Front - 275/35/19 Rear. No issues. Car is still fast. Next set of tires will either be square 275 set up or 255/285 (maybe 275) pending tire choices.

[happos2]

Originally Posted by Longwong

If you don't follow than probably no point in explaining as you likely will not care. But go check out the weight of the 275/35 tire compared to the 265/35. Every couple pounds of rotating mass in the tire is a big impact on acceleration, mileage and handling. Also if you are changing the relative diameter of the cars front and rear which you would if you ran 245's up front, than you upset the balance that the car was designed for when you are pushing the car as the differential will be slightly receiving different wheel speeds.

If you are doing it for looks which you are obviously that is fine. And what does a supercharger have to do with it? Its called needing more traction at which point some extra weight in the tires is easily made up for by the 150 extra power a supercharger has and the ability to put the power down instead of spinning is worth a few extra pounds on the tire

Differential problems...No.

[Denk]

Originally Posted by CSBM5

Re tire weight. Changing to a 275/35 from a 265/35 will have an UNMEASURABLE effect on the car's acceleration due to the minor weight addition. It will be within the repeatability window of the data logging in acceleration tests. Also, since it only has an effect when there is acceleration of the wheel, AND since that effect drops of exponentially with speed (i.e. 1st gear has the highest acceleration rate, then accel rates fall successively as speeds climb), there will be zero effect on measured gas mileage that you can measure. At minor acceleration rates (essentially all of daily driving), it's trivial, and at a rather constant speed (cruising) there is ZERO contribution to minor effect of a small increase in rotational inertia.

I A/B'd stock sizes with 255/35, 275/35 and it did have a measurable effect with my butt dyno. Besides weight there is also an increased OD which plays into the equation. Maybe on paper it shouldn't be noticeable but after real world testing I noticed a difference and that was just street driving. Stock size definitely feels better to me...that's a biggie to me.

[CSBM5]

Originally Posted by Denk

I A/B'd stock sizes with 255/35, 275/35 and it did have a measurable effect with my butt dyno. Besides weight there is also an increased OD which plays into the equation. Maybe on paper it shouldn't be noticeable but after real world testing I noticed a difference and that was just street driving. Stock size definitely feels better to me...that's a biggie to me.

Instrumented tests will show you that any difference was within the bounds of error for the test. Butt dynos always lie. Expected changes are found almost without question...hence the reason double-blind testing was established a long time ago in the scientific community.

[Denk]

Originally Posted by CSBM5

Instrumented tests will show you that any difference was within the bounds of error for the test. Butt dynos always lie. Expected changes are found almost without question...hence the reason double-blind testing was established a long time ago in the scientific community.

Amen to the Pepsi challenge.

[Dave07997S]

Originally Posted by Longboarder

Running incorrect sizes can interfere with some of the car's systems such as ABS. For example, if you run a square 275 35 19 F and 275 35 19 R, the car will think something is wrong because the back wheels should be spinning slower than the fronts because of the factory staggar.

A 255 35 19 and 275 35 19 is what I run with PSS and will not interfere at all.

It's all about maintaining the appropriate ratio.

It does not affect ABS, it can affect the DSC. As someone who has been running a 255/285 setup it really is minimal. Even Ben from Tirerack has brought this up that it really is minimal.

Dave

[M3/4 life]

There's been a change, I'm now going with the Velos Solo VII 19x8.5 f 19x11 r on 255/35/19 f 295/30/19 wrapped in M Pilot Super Sports!

[Longboarder]

Originally Posted by Dave07997S

It does not affect ABS, it can affect the DSC. As someone who has been running a 255/285 setup it really is minimal. Even Ben from Tirerack has brought this up that it really is minimal.

Dave

If you ran smaller tires on the rear, ABS would go out, similar to what happens if the rears are continually spinning and the front's arent but yeah no one's gonna purposefully run smaller rear tires.

[ben@tirerack]

Originally Posted by Dave07997S

It does not affect ABS, it can affect the DSC. As someone who has been running a 255/285 setup it really is minimal. Even Ben from Tirerack has brought this up that it really is minimal.

Dave

Agreed. In THEORY screwing around with the relative diameters front to rear could confuse the traction control. In practice, the M3 is quite tolerant of all the tire size shenanigans that you rascals can come up with.