[jules_78th]

For my 19" summer setup on my M240i vert, I'm running staggered 225/35/19 at 37 PSI and 255/30/19 at 41 PSI. These are set to cold.

I swapped in my winters now and looking at my summers, and I noticed I'm almost at the wear bar in the center for the rears with way more thread on the inner and outer. Fronts looks good, I can see the center to have used more thread than the inner/outer, but not like the rear. These tires are still pretty new, so I only probably put 10k on them and its not looking good.

I'm thinking I'm overinflating them, especially the rears. What PSI do others run thier staggered 19's? and how's your thread wear?

[MarcoZandrini]

Originally Posted by jules_78th

For my 19" summer setup on my M240i vert, I'm running staggered 225/35/19 at 37 PSI and 255/30/19 at 41 PSI. These are set to cold.

I swapped in my winters now and looking at my summers, and I noticed I'm almost at the wear bar in the center for the rears with way more thread on the inner and outer. Fronts looks good, I can see the center to have used more thread than the inner/outer, but not like the rear. These tires are still pretty new, so I only probably put 10k on them and its not looking good.

I'm thinking I'm overinflating them, especially the rears. What PSI do others run thier staggered 19's? and how's your thread wear?

Center tread wear indicates over=inflation. I have 18" wheels on my car and I run 35psi front and 37psi rear. Wear is even on all 4 tires.

[overcoil]

jules_78 how many miles are on your 19-inch summer tire ?

[flypenfly]

37/41 cold is too high.

[amutti]

36/41 is stock for my 2021 m240 convertible. It's what I've been running. About 10,000 miles and a little more wear on the center.

[overcoil]

Originally Posted by flypenfly

37/41 cold is too high.

not as a recommendation or to answer the question:

37/41 may be high and causing excessive central wear but I like those psi's - I think the Michelin summer tires have the best ride at those psi's.

[Kernel Kurtz]

Keep in mind that unless otherwise specified, the factory recommended pressures are for a fully loaded vehicle. If your trunk is usually empty and you don't have back seat passengers you should probably run somewhat lower in the rear tires.

[dradernh]

Originally Posted by Kernel Kurtz

Keep in mind that unless otherwise specified, the factory recommended pressures are for a fully loaded vehicle.

Did you come to this conclusion based upon the outlined graphic in the image below? I ask because even though the image came from my owner's manual, I can find no text in the manual stating that that's the case.

A Google search didn't enlighten me much, except that another BMW owner stated that the graphic is intended to communicate that the pressures listed are for loads up to that number of people and luggage.

BTW, is the luggage portion of the graphic meant to say one bag per person in the trunk or one bag in total in the trunk?

This is separate from the issue of load capacity, of course. And it begs the most obvious of questions: who drives around with their car loaded with 600-800# of extra stuff? Unless it's a mom or dad with one or more kids, I almost never see a vehicle with two or more people in it.

A BMW forum commenter from Europe indicated that Euro stickers and manuals impart much more clearly what BMW intends us to do with tire pressures.

After experimenting a bit, and given that I've got a wide and square tire setup, I've changed from 35 F / 39 R to 34 or 35 all around depending upon how I'm feeling that day. Except for the psi, that's what I would do at the track. That approach works well for me when I'm leaning a bit on the car on back roads, which is generally what the car is set-up and used for.

[Kernel Kurtz]

Originally Posted by dradernh

Did you come to this conclusion based upon the outlined graphic in the image below? I ask because even though the image came from my owner's manual, I can find no text in the manual stating that that's the case.

A Google search didn't enlighten me much, except that another BMW owner stated that the graphic is intended to communicate that the pressures listed are for loads up to that number of people and luggage.

BTW, is the luggage portion of the graphic meant to say one bag per person in the trunk or one bag in total in the trunk?

This is separate from the issue of load capacity, of course. And it begs the most obvious of questions: who drives around with their car loaded with 600-800# of extra stuff? Unless it's a mom or dad with one or more kids, I almost never see a vehicle with two or more people in it.

My understanding is that NHTSA mandates that when only one set of pressures is given, that it always be at max load because that will always be a safe default. I have never questioned this, but have never researched it either. A quick Google suggests the technical details are in sec 4.3.4 in this document.

https://www.govinfo.gov/content/pkg/...sec571-110.pdf

I have seen many manufacturers provide tables of pressures for various loads and speeds, and that is obviously a better plan. Motor Trend had a good article on it a few years back that also seems to back my assertion.

"Every car comes with an NHTSA-mandated tire pressure label, usually found inside the driver's door, that lists a set of tire pressures as well as the maximum combined load for passengers and cargo. NHTSA will simply tell you to run those max-load cold tire pressures, but there's much more to inflation specs..."

https://www.motortrend.com/features/...ssure-sticker/