mjX3 wrote

My OEM recommendations at 41psi front and 48psi back which I think are pretty high. No wonder my tires in the past have been wearing quicker in the middle.

Do you also have over 100 mph speed selected? That will raise pressures drastically. I have under 100mph selected and have no issues above 100mph for what it’s worth.

So I'm still running 255/40/21 & 295/35/21 MPS4S on 718M this year and loving the tires, but I'd like to swap out the rims for a set of 829M to match the 826M wheels on my G80. A stupid reason, I will grant you, and also probably mostly academic given the rarity of second-hand 829's, but none-the-less, I'll ask the question:

Will my existing Pilot Sport 4S 255/40/21 & 295/35/21 fit on stock 829M rims on my 2018 G01 X3 M40i, without looking all stretched or poked or rubbing strut towers or fenders or whatever?

Thanks in advance.

Vote Quimby wrote

So I'm still running 255/40/21 & 295/35/21 MPS4S on 718M this year and loving the tires, but I'd like to swap out the rims for a set of 829M to match the 826M wheels on my G80. A stupid reason, I will grant you, and also probably mostly academic given the rarity of second-hand 829's, but none-the-less, I'll ask the question:

Will my existing Pilot Sport 4S 255/40/21 & 295/35/21 fit on stock 829M rims on my 2018 G01 X3 M40i, without looking all stretched or poked or rubbing strut towers or fenders or whatever?

Thanks in advance.

@Vote Quimby - What are you running your tire psi in the front and rear?
Are you getting an error message about the TPMS ? I have the same setup as you and after you change out your tires in the X3 G01, you select the season and tire profile but since the rears are not OEM spec, there is no option. What are you selecting?

notchy wrote

@Vote Quimby - What are you running your tire psi in the front and rear?
Are you getting an error message about the TPMS ? I have the same setup as you and after you change out your tires in the X3 G01, you select the season and tire profile but since the rears are not OEM spec, there is no option. What are you selecting?

If you're on y-rated tires, the only time it'd matter is if you constantly run well over 100mph at a low pressure. If you run <100mph 99% of the time, just pick the minimum cold psi on the door jamb sticker.

Looks absolutely great!

freshxdough wrote

Do you also have over 100 mph speed selected? That will raise pressures drastically. I have under 100mph selected and have no issues above 100mph for what it’s worth.

Yes I did have over 100 selected, however, I didn't have to change that. I selected the "Winter/All Season, Current- Other" tire option and reset the tire pressures. Once I did that, the "recommended" tires pressures disappeared, thus making the low tire pressure warnings disappear too. Problem solved.

mjX3 wrote

Yes I did have over 100 selected, however, I didn't have to change that. I selected the "Winter/All Season, Current- Other" tire option and reset the tire pressures. Once I did that, the "recommended" tires pressures disappeared, thus making the low tire pressure warnings disappear too. Problem solved.

You should use the correct tire pressure for the correct tires and speed. If you have OEM sizes, use the OEM size for the rear tire. And select above or under 100. I choose Summer Other because I have 255/295 Michelin PS4S. I go about 35/35

freshxdough wrote

You should use the correct tire pressure for the correct tires and speed. If you have OEM sizes, use the OEM size for the rear tire. And select above or under 100. I choose Summer Other because I have 255/295 Michelin PS4S. I go about 35/35

The problem with the summer option checked was that it was recommending 40psi for front and 48 psi for back. If with "over 100" checked, I feel like those tire pressures are too high.

freshxdough wrote

You should use the correct tire pressure for the correct tires and speed. If you have OEM sizes, use the OEM size for the rear tire. And select above or under 100. I choose Summer Other because I have 255/295 Michelin PS4S. I go about 35/35

I am going to try your recommendation and choose "summer other" and set the psi for all 4 tires to 35 psi

When owning a fast car, I think folks should know the basics why tire pressures need to be up'd relative to speed AND tire rating - the higher the tire rating, the lesser the need to fiddle with the pressure unless driving >150mph on y-rated tires. This isn't a problem in most cases especially on w- and y-rated tires unless driving >130mph REGULARLY. But then again, it's not a one-size-fits-all type of deal.

That setting on i-drive is half-gimmick IMO.

Sorry for reviving this old thread, but i'm just checking something...

I have the "21 individual staggered wheels on my M40i and want to switch to non RFT tyres.

Would the following set-up work?

Front - 255/40/21
Rear 285/35/21

this would be 0.3% difference in diameter... seems ok doesn't it?

Sorry for reviving this old thread, but i'm just checking something...

I have the "21 individual staggered wheels on my M40i and want to switch to non RFT tyres.

Would the following set-up work?

Front - 255/40/21
Rear 285/35/21

this would be 0.3% difference in diameter... seems ok doesn't it?

Yes, should be fine.

I am running the same size, except other rims.

I will go to 265/40 R21 and 305/35 R21 Pirelli PZ4.

OEM size 718M rims.

Have to replace my X's RFT shoes, seems that for the rear, 295/35/21 fits like a glove
But front has created some discussions, 255 or 265/40/21 ?

And I can find Michelin Pilot Sport Pilot Sport 4S and Michelin Pilot Sport SUV ?
Which one to go?
Seems that SUV version of the whole tire set is ~144e cheaper than 4S.

Anyone?

mailman_fin wrote

OEM size 718M rims.

Have to replace my X's RFT shoes, seems that for the rear, 295/35/21 fits like a glove
But front has created some discussions, 255 or 265/40/21 ?

And I can find Michelin Pilot Sport Pilot Sport 4S and Michelin Pilot Sport SUV ?
Which one to go?
Seems that SUV version of the whole tire set is ~144e cheaper than 4S.

I'm willing to bet that the SUV tire has a stiffer sidewall.

A lot of people don't realize that when you go up in size on the front tires you are going to slow response time down. Going up several steps up in size are going to really slow things down so that's what you're feeling.

glennbk wrote

I'm willing to bet that the SUV tire has a stiffer sidewall.

I bet that too.
But any other differencies, example fitment to OEM size 718M rims?

Leem40i wrote

A lot of people don't realize that when you go up in size on the front tires you are going to slow response time down. Going up several steps up in size are going to really slow things down so that's what you're feeling.

What response time you mean?
And what is your mentioned "several steps"?

Going 245 -> 265 and 275->295 does not sound so big step, imo.

mailman_fin wrote

I bet that too.
But any other differencies, example fitment to OEM size 718M rims?

I doubt it. I put Michelin Pilot Sport All Season 4 and have had no issues at all. The X3 is much more compliant, adsorbs bumps much better and the rims are better protected by the tires.

glennbk wrote

I doubt it. I put Michelin Pilot Sport All Season 4 and have had no issues at all. The X3 is much more compliant, adsorbs bumps much better and the rims are better protected by the tires.

ORdered SUV versions.
No All Seasons here, as we have to have real winter tires as well.

mailman_fin wrote

ORdered SUV versions.
No All Seasons here, as we have to have real winter tires as well.

My apologies. Forgot that Europe doesn't have the same options in tires.