[dmanb2b]

Originally Posted by ASAP

my man... you're not getting squirrely in this 510 HP Suv at 60 MPH lol...

I drove an X3M COMP around PBIR and that was the last thought on my mind... an M2 Comp which is the twitchiest car BMW makes that has a lower TQ band and the same 265 rear tires doesn't get twitchy at 60 MPH lol... less TQ down low and a shorter body would make it squirrlier, a stronger top end at a higher speed won't... (not at this power / weight distribution). I could see the car being bouncy but that's just the crappy BMW adaptive suspension doing its work not the tires... but there is no way it's squirrely.

Nope, not bouncy. Loose... particularly when boost kicks in. I'm on KWs so you can scratch the suspension, but now that you mention it, that's another added benefit of the larger tire sizes on stock suspensions, less twitchiness and a more compliant (softer) ride. Comparing an M2 to a 4600lb car shows your lack of considering the difference in inertia. A heavier car is a lot harder to both stop and accelerate. The higher the mass and resulting inertia, the greater the reluctance of the object (vehicle)to move or change speed. Apply 500hp to the same 265 size tire/contact patch in a vehicle that has significantly more mass, the heavier vehicle will break loose easier. Same concept as to why an M2 will always outhandle an F97 in corners given the same tire sizes...the only way to fix that is to add tire to the heavier car.

[Edgar_FriendlyX3M]

Originally Posted by dmanb2b

The x-drive system is more rwd based than the m40i and stock for stock a 100+hp difference vs the b58 is not insignificant. The power/tq band on the s58 is also much higher in the RPM range than the B58, so launches are not really a problem, but getting squirrely in a 60-120 roll is not confidence inspiring (especially in the wet) and more rubber certainly comes in handy when "tossing" a 4,600lb vehicle into a corner at 60+ mph.

So yeah, looks may be a benefit, but I'll take improved grip all day long...especially once these things are tuned. The 265/295 setup still gives you that fun experience, but with more lateral grip and stability at speed.

Since I added the xhp trans tune, if I'm in sport plus everything and drivelogic s3, the 1-2 upshifts will break the rear tires loose briefly even if it's damp. I agree with you the added tire width in back would certainly help.

[ASAP]

Originally Posted by Edgar_FriendlyX3M

Since I added the xhp trans tune, if I'm in sport plus everything and drivelogic s3, the 1-2 upshifts will break the rear tires loose briefly even if it's damp. I agree with you the added tire width in back would certainly help.

you guys are aware the biggest factor in tire traction is compound not width... right?

https://www.roadandtrack.com/car-cul...res-more-grip/

[Edgar_FriendlyX3M]

Width still helps. Otherwise they wouldn't spec out a Lambo with 315 or 335 rears. 🙂

[ASAP]

Originally Posted by Edgar_FriendlyX3M

Width still helps. Otherwise they wouldn't spec out a Lambo with 315 or 335 rears. 🙂

Correct... a major component of the massive rears on those cars is wear around a track as those are track cars... why would bmw not throw on 295 rears? what would be their hesistancy? A tesla model s plaid w over 1000 hp and an absurd tq curve has 285 rears lol.

[Edgar_FriendlyX3M]

Originally Posted by ASAP

Correct... a major component of the massive rears on those cars is wear around a track as those are track cars... why would bmw not throw on 295 rears? what would be their hesistancy? A tesla model s plaid w over 1000 hp and an absurd tq curve has 285 rears lol.

If I had to guess, for the sake of fuel mileage, less weight, and added cost. When it comes down to it, I'd go wider tires out back more for aesthetics but also the increase in handling and ride. It's not crucial and I'm not racing the car so my intentions may vary from others. It's part of the fun of having performance cars too I guess.

[iSpY]

Hi,

Does anyone have experience with the Michelin Pilot Sport 4 SUV vs the Pirelli P Zero (PZ4)? I have a non comp (20'' rims) and need replacement on the 2 rear tires just below 9k. Looking for something better than Pirelli and this is the only one I can find with the same size.

[Scottycs19]

For acceleration on street tires it plays a very large roll.

Originally Posted by ASAP

you guys are aware the biggest factor in tire traction is compound not width... right?

https://www.roadandtrack.com/car-cul...res-more-grip/

[BMWX3MCompUK]

going with 295/35 265/40 set up from my factory conti 6 set up.

Gone with conti cs 7's got a great deal for them £198per tyre

will report back how it feels

[Kyxap]

I needed new tires after 18,000 mi for my original equipment Michelin PS 4S 255/40 front and 265/40 rear. After some jerking around by local tire shops (265/40 front and 295/35 rear "won't fit your vehicle"), I asked my dealer to do it, and there was no hesitancy at all, other than checking to see if they were available in BMW spec ("star"). Price was competitive. On they went. No concerns from them at all about X5M "fronts" going on the rear of my X3MC or X3MC "rears" going on my front. I took off the 10mm Dinan spacers I had on there with the original tires - I think it would have been too much and I like the look as is. I haven't driven enough yet to see if I can tell a difference in the handling, ride, noise, etc.

[BMWX3MCompUK]

295/35 R21 conti sport 7's on

SLightly underinflated here as the tyre shop put in 32psi

thinking of putting in 35/36 psi in later

[Max Well]

Originally Posted by ASAP

i'll be the one to ask the obvious dumb question here... isn't the point of the 265 rears to keep the real M car more tossable / rotatable? The m40i has a thicker rear (275) with 20inch plus wheels to prevent that as it caters to a different crowd?
You guys having awd launch issues or something?

Originally Posted by ASAP

I think it's perhaps me that's confused as to what the value in this upgrade is...? Someone said looks and so far that's the only thing that I've read that makes sense... and if that's the case, so be it.
Otherwise, are people spinning tires on launch in a AWD tank SUV that weighs 4610 w only 510 hp? Or is the car too twitchy? I find both a tad bit hard to believe.

My OEM-sized wheels/tires routinely skip and spin well into 2nd when launching at the Strip with OEM rec psi and down into the 34-35 rear range. I've tried down to 32F/30R but that was with a low DA and temps in the 40s so no way the PS4S could be expected to grip then. I just don't get that many runs in at public events to try a wide range of psi settings to formally evaluate as I would hope. I heard the Announcer on the track radio station comment at one event while I was staging in my wife's X3MC LCI as to whether I could beat a previous run's 11.700s 'if he doesn't spin' (as discussed in the 1/4 thread: https://x3.xbimmers.com/forums/showp...&postcount=381 ).

Here's an image from last weekend taken by the Track Photographer just after launch which shows the skipping well (and when shadows are lightened the fronts also appear to be skipping, although looks to be only three). All settings in Sport+. My gut feeling is the 265/295 combo prob would improve the dry grip (as the video link you shared seemed to support - https://x3.xbimmers.com/forums/showp...&postcount=289), but I'll be staying OEM size for my stock record attempts.

[Scottycs19]

Just ordered 295/265 Pirelli Scorpion Zero A/S Plus. Will share my results!

[dmanb2b]

Originally Posted by Max Well

My OEM-sized wheels/tires routinely skip and spin well into 2nd when launching at the Strip with OEM rec psi and down into the 34-35 rear range. I've tried down to 32F/30R but that was with a low DA and temps in the 40s so no way the PS4S could be expected to grip then. I just don't get that many runs in at public events to try a wide range of psi settings to formally evaluate as I would hope. I heard the Announcer on the track radio station comment at one event while I was staging in my wife's X3MC LCI as to whether I could beat a previous run's 11.700s 'if he doesn't spin' (as discussed in the 1/4 thread: https://x3.xbimmers.com/forums/showp...&postcount=381 ).

Here's an image from last weekend taken by the Track Photographer just after launch which shows the skipping well (and when shadows are lightened the fronts also appear to be skipping, although looks to be only three). All settings in Sport+. My gut feeling is the 265/295 combo prob would improve the dry grip (as the video link you shared seemed to support - https://x3.xbimmers.com/forums/showp...&postcount=289), but I'll be staying OEM size for my stock record attempts.

I should know this, but what wheels are you running? Specs. offset?

[Max Well]

Originally Posted by dmanb2b

I should know this, but what wheels are you running? Specs. offset?

All OEM specs, but saving 44 lbs unsprung weight with the combo of BC Forged RZ05 (21x9.5 +31, 21x10 +39)/Michelin PS4S (255/40 R21, 265/40 R21) - 217 lbs . More images and discussion in the Members' Wheel and Tire thread: https://x3.xbimmers.com/forums/showthread.php?t=1949903

[dmanb2b]

Thank you I bet you can feel that🤓

[Max Well]

Originally Posted by dmanb2b

Thank you I bet you can feel that🤓

I truly can tell the difference - even in daily driving with the handling and acceleration. Suspect my 0.031s improvement from my previous personal best is mostly because of that wt savings. Wish I had made the change to lighter wheels years ago!

[MrGraff]

Just bought a new to me 2021 X3M, unfortunately the previous owner/dealer didn't handle the tires appropriately. So Im looking to do the 295/35r21 rears, and 265/40r21 fronts. I have the 765M wheels, will I have any issues with these wheels and those tires?

[dmanb2b]

Originally Posted by MrGraff

Just bought a new to me 2021 X3M, unfortunately the previous owner/dealer didn't handle the tires appropriately. So Im looking to do the 295/35r21 rears, and 265/40r21 fronts. I have the 765M wheels, will I have any issues with these wheels and those tires?

nope

[MrGraff]

Originally Posted by dmanb2b

nope

No spacers or any change to a stock X3M needed for these to fit and not rub ? my dealer is pretty apprehensive.

Decided to go with Pirelli Scorpion All Seasons.

[95wildtt]

Originally Posted by MrGraff

No spacers or any change to a stock X3M needed for these to fit and not rub ? my dealer is pretty apprehensive.

Decided to go with Pirelli Scorpion All Seasons.

Nope, no issues... had that setup with my 765s and no spacers needed.
Lots of people on here running that setup, or with then newer 892 OE Wheels.

[Scottycs19]

Just did the Pirelli Scorpion Zero AS, no complaints!

Better traction in temps below 60 too.