[_Tony_]

A couple weeks ago I had a local shop put on a staggard setup of 235/40ZR-19 MICHELIN PS4S and 265/35ZR-19 PS4S on my 2015 335i.

After the install I talked to the technician and he said he set the tire pressure to 41 psi.

That seems a bit high. Does anyone know if that is an issue? Any insight into whether I should keep that pressure or drop it back down to 38 psi?

[sspade]

Recently left the dealer and they asked permission to set the tire pressure to 32psi cold. They mentioned this is the proper psi for this body "from the factory."

I agreed, no problem.

When they get warm, psi increases to 34 or 35 max.

[cfm56d7b]

For OEM 19" run flat tires, BMW suggests 33 PSI in the front and 38 PSI in the rear. The tire pressure on non run flats should be higher to account for softer sidewall but is 41 PSI on all tires correct?

[sspade]

Originally Posted by sspade

Recently left the dealer and they asked permission to set the tire pressure to 32psi cold. They mentioned this is the proper psi for this body "from the factory."

I agreed, no problem.

When they get warm, psi increases to 34 or 35 max.

To further clarify...

This was with Continental DWS 06 (the best, non run-flat all season they offer).

Dealer recommends 32psi cold, all around.

Had I been wearing top of the line Michelin... the result would be the same.

[rjd_F30]

I run PS4S's as well, 245/30-20, and set them to 34 cold all around. As long as they're not super high (41 cold is closing in on that) or super low ( <30 cold) it'll be fine, it's kind of a preference thing. That said, I'd drop it down to at least 38 psi. IIRC my tires even say on them do not inflate over 40psi, though that may vary for different sizes.

[alohasurftoad]

the driver door sill placard lists cold tire pressures. since non-runflats have a softer sidewall than runflats, i'd initially add 3 psi to whats listed and then adjust if needed, after driving around and seeing what the comfort, steering response, etc., is like.

[sspade]

Originally Posted by alohasurftoad

the driver door sill placard lists cold tire pressures. since non-runflats have a softer sidewall than runflats, i'd initially add 3 psi to whats listed and then adjust if needed, after driving around and seeing what the comfort, steering response, etc., is like.

I think this makes a ton of sense considering these vehicles are shipped with RFT.

I believe a couple psi increase to compensate for softer walled tires makes sense.

Putting us somewhere in the 34 psi cold, 36 warm range.

At the end of the day, as mentioned above - it comes down to personal preference and feel once you are within the 32-38 range. Anything lower or higher may need adjustment.

[NoobCola]

BMW dealer set my tire pressure to 32psi front 36psi rear after taking it in a few days ago.

[_Tony_]

Thanks for all the comments. I think I will add the 3psi.

[luckstr]

Originally Posted by NoobCola

BMW dealer set my tire pressure to 32psi front 36psi rear after taking it in a few days ago.

What model, year, trim , tire brand and tire size, square or staggered setup ? My 2017 440i convertible door placard says 36psi front, 41 psi rear (cold) on 19" staggered set up, Pirelli P Zero RFT. Seems as if these placard pressures coming from factory are all over the map between trims.

[chowser51]

Yep. My f33 lists 33/41 for oem. I switched to goflats and have been running 34/43 which is what I find comfortable.

[Fez_7]

Does anyone know what is recommended by BMW for staggered set 225/45/18 front and 255/40/18 rear on runflats?

[thejeremyman9]

Originally Posted by Fez_7

Does anyone know what is recommended by BMW for staggered set 225/45/18 front and 255/40/18 rear on runflats?

OEM door spec for 225/45/18 square is 32F/38R. There is also the note to increase to 39F/46R if driving over 100mph.

For OEM 225/40/90 and 255/35/19, it is 35F/38R or 39F/44R if over 100mph. This was my OEM spec for RFT. I switched to PS4S non runflat with a change in front size to 245/35/19 (still 255 rear) and i run about the same now, 36F/38R, as my cold PSI setting. It seems to work well overall. I dont have a problem hooking 1st year from a dig really, but if you did, you could probably lower to 35 or 36 psi square.

[luckstr]

Originally Posted by cfm56d7b

For OEM 19" run flat tires, BMW suggests 33 PSI in the front and 38 PSI in the rear. The tire pressure on non run flats should be higher to account for softer sidewall but is 41 PSI on all tires correct?

What model, trim, tire set-up? The pressures on door placards vary significantly based upon these factors.

[luckstr]

Originally Posted by chowser51

Yep. My f33 lists 33/41 for oem. I switched to goflats and have been running 34/43 which is what I find comfortable.

Hi chowser51, doesn't this mean that after some driving those rear pressures will increase to somewhere between 43-46 due to heat? Thanks

[chowser51]

It rarely gets past 43. it's so cold here and it always drops to 41 the next day anyway. my gauge might be broken. lol

I just checked a little bit ago and i'm at 31/40 right now.

[luckstr]

Originally Posted by chowser51

It rarely gets past 43. it's so cold here and it always drops to 41 the next day anyway. my gauge might be broken. lol

I just checked a little bit ago and i'm at 31/40 right now.

After driving around 100 miles on a warm day (approx 90 deg), I have pulled into my garage & measured my tire pressures and they were (starting out at 36 front/41rear cold): 38-39 front/43-44 rear. Of course the next morning after the car sits around 10 hours the pressures are back down to 36 front/41 rear. I'm just wondering if I want to put my 'cold' pressures at something like 34 front/38 rear. I'm putting the new tires on tomorrow so I'll play with tire pressures for a few weeks and come up with something. Thanks