Tire pressures- what's best?

[alohart]

Only if you were regularly running the thing at full gross max weight might it help raising the tire pressure much of any.

I run both fronts and rears at 10 psi over BMW's recommendation in hopes of protecting my expensive wheels from damage when driving on our pothole-strewn roads. That means running the rears at their maximum inflation pressure as indicated on their sidewalls. I'm sure that this reduces my traction somewhat, but it might also reduce the rolling resistance somewhat, so I'm willing to accept the compromises. Being radial ply tires, I don't expect this to affect tread wear much.

 

[elptex]

I started running mine higher, at 37 up front and 47 in the back.

I significantly prefer the way it rides much better at these numbers (I'm on the 19"s). The car rides much less 'bouncy' over bumpy and undulating roads (poor condition English country lanes constitute 50% of my miles) and the turn-in handling feels much more precise.

I'm not sure how this will affect wear, though in every other car I have owned I have run a higher pressure and not had any adverse wear. In particular, several sets of tires lasted far beyond the average. How you drive has a significant play on wear.

 

[mlsstl]

We test drove a REX today and noticed the "whoop whoop" noise that others have mentioned. The car had the 20" wheels. Have no idea what the tire pressures were set to.

Is this related to tire pressure or is it just a noise that cars with that wheel size are stuck with? It seemed quite annoying during our test drive.

If it can't be fixed, it may be a deal killer -- I don't think I'd want to live with that as a constant background noise.

Thanks in advance for any comments.

 

[WoodlandHills]

In my experience it cannot be fixed. My car did it with the tire pressures that the dealer set when it was delivered (uniformly underinflated) and it does it now with the tires at the recommended pressures. It is loudest when cornering on smooth dry pavement, so if you live in a ritzy area with freshly paved streets you will hear it all the time. With the 20's being so harsh riding over any sort of wornout pavement, most of the time the rattles from the interior are a bigger issue. See the ongoing thread on fixing the rattles from the glovebox and center display.....

 

[i3atl]

Based on several owner reports, and test drives, it seems that it can be resolved by replacing the tires with 20" EP500s with a later production date - we don't know exactly when they fixed them, though.

 

[mlsstl]

Thanks for the replies. We also noticed that the sound was most prominent when driving on very smooth roads -- the better and more pristine the asphalt, the louder the sound.

From your comments, it seems like it is related to the tread pattern of the specific tire. Makes you wonder how that made it past BMW's design checks and quality control teams!

Haven't made a purchase decision yet, but will make it a point to ask for a different set of tires if we proceed. Sounds like that will give the best chance for fixing things. And, if they don't agree, we have no immediate need to replace our Mini right now since it is paid off and running fine.

 

[Sparky]

I think you will find the 19" tire/wheel combination will offer a quieter, smoother ride.

 

[i3atl]

From your comments, it seems like it is related to the tread pattern of the specific tire. Makes you wonder how that made it past BMW's design checks and quality control teams!

That does seem to be the case, but there's no visible difference between the tread pattern on the 20" tires that make the noise and the newer ones that don't.

 

[i3atl]

I think you will find the 19" tire/wheel combination will offer a quieter, smoother ride.

I'm happy to swap with any 20" wheel owners who want the quieter/smoother ride of the 19s. Anyone interested please send me a PM.

 

[Ruffles]

I'm glad to hear other people saying the pressure sensors are off. That has been my experience as well.

 

[S3RDP]

I started running mine higher, at 37 up front and 47 in the back.

I significantly prefer the way it rides much better at these numbers (I'm on the 19"s). The car rides much less 'bouncy' over bumpy and undulating roads (poor condition English country lanes constitute 50% of my miles) and the turn-in handling feels much more precise.

I'm not sure how this will affect wear, though in every other car I have owned I have run a higher pressure and not had any adverse wear. In particular, several sets of tires lasted far beyond the average. How you drive has a significant play on wear.

Is this still your recommendation? I too drive a lot on English country lanes and notice that the car can get quite "bouncy". Have you noticed any degradation inn tyre wear?

 

[peteinlongbeach]

I'm glad to hear other people saying the pressure sensors are off. That has been my experience as well.

Not mine. I bought a new digital pressure gauge, reset all my tire pressures and the TPMS, and the status readout was very close. Keep in mind that temperature differences will affect the pressures and the readout.

 

[Arm]

Can anyone explain why...on the i3S models...the tire pressure values changed from 33/41 F/R to 39/44 F/R? Irregardless of whether it's BEV or REX.

I cannot get an answer or explanation for it. I see no difference physically or suspension-wise between a 2018 and 2019 and up model i3S.

The only reason I can personally think of is perhaps BMW re-evaluated the tire pressures for the i3S models for 2019 and on and updated it for efficiency purposes. However, I ask myself if that were the case, they would be proactive about it and let 2018 i3S model owners and the dealers to update the pressures on their cars.

Any thoughts on this?