[agentorange]

Had a loaner X3 yesterday. Sdrive, 18" wheels, 38 PSI showing all round on the pressure monitor (sigh). Anyway, twice on freeways here in Vegas we had a touch of crosswind and the thing went into greasy weasel mode. Only time I've felt worse in an SUV was when the alignment went out on the wife's GLC. FFS, my 2005 Xterra on 75 profile boots was more stable in a straight line.

The X3 drove fine so long as there was no wind. Anybody else noticed this? Could it be the caster is off or some such?

[RazorX3]

Originally Posted by agentorange

Had a loaner X3 yesterday. Sdrive, 18" wheels, 38 PSI showing all round on the pressure monitor (sigh). Anyway, twice on freeways here in Vegas we had a touch of crosswind and the thing went into greasy weasel mode. Only time I've felt worse in an SUV was when the alignment went out on the wife's GLC. FFS, my 2005 Xterra on 75 profile boots was more stable in a straight line.

The X3 drove fine so long as there was no wind. Anybody else noticed this? Could it be the caster is off or some such?

Same. I can definitely feel slight (really tiny) deviations whenever there's crosswind on the highway, I had an F20 LCI before the X3 and it didn't budge to the wind at any speed. However I got used to it real quick and it doesn't bother me anymore.

[Torinalth]

maybe a mild feel.... but nothing substantial like you are describing. maybe the alignment is off giving it the feel of less connection>?

[BMWZ4]

Nothing here. I do quite a bit of open highway driving as well

[chassis]

sDrive + 38psi + crosswind = greasy weasel

xDrive + 50psi + crosswind = no greasy weasel

[IslandDriver]

sDrive, ughhh, just no.

[agentorange]

Originally Posted by chassis

sDrive + 38psi + crosswind = greasy weasel

xDrive + 50psi + crosswind = no greasy weasel

Is 50psi the normal pressure? Seems like an awful lot unless your are loaded to the gunwales.

[chassis]

I don't think 50psi is the normal pressure. I intentionally air up to 50psi because it doesn't hurt ride quality (my opinion) and increases tread life. German vehicles' air pressure specs are generally oriented towards ride quality and maximum grip. Max grip can be viewed as higher safety and may lead to fewer lawsuits for the manufacturer. Ride quality means fewer complaints from new owners after the first pothole.

However, tire wear suffers at the OEM tire pressure spec.

On my M-B I experienced excessive shoulder wear at the OEM tire pressure. I am mild driver and normally have one adult in the vehicle. I aired up to 50psi and the wear evened out. I needed new tires at 40k miles, the lowest mileage I have achieved on any tire (Conti CrossContact LX Sport). I air my wife's G01 X3 xDrive factory RFTs into the upper 40s.

[agentorange]

Originally Posted by chassis

I don't think 50psi is the normal pressure. I intentionally air up to 50psi because it doesn't hurt ride quality (my opinion) and increases tread life. German vehicles' air pressure specs are generally oriented towards ride quality and maximum grip. Max grip can be viewed as higher safety and may lead to fewer lawsuits for the manufacturer. Ride quality means fewer complaints from new owners after the first pothole.

However, tire wear suffers at the OEM tire pressure spec.

On my M-B I experienced excessive shoulder wear at the OEM tire pressure. I am mild driver and normally have one adult in the vehicle. I aired up to 50psi and the wear evened out. I needed new tires at 40k miles, the lowest mileage I have achieved on any tire (Conti CrossContact LX Sport). I air my wife's G01 X3 xDrive factory RFTs into the upper 40s.

If the M-B you had was a GLC I'm not surprised. My wife has one and the front wheels reach some interesting angles during tight maneuvers.

Some clown at the dealership put 40-41 in all the tires on my F30 on Wednesday. Stock pressure is 32F 36 R. The ride was like taking a skateboard over cobbles and the front end and back end appeared to be from two different cars all of a sudden.

I'm all about grip, grip and more grip. If I'm not wearing out the boots on a performance vehicle in about 30k miles I need to sell it and buy a four banger Accord.

I couldn't run the pressures you have. A couple of years ago I was given a Range Rover Evoque as a loaner with grossly overinflated tires, about 45 PSI. My best description of the handling is imagine a 15-year old in her first pair of stilettos and add three glasses of wine. When you looked from the back of the vehicle you could visibly see that only the center of the tread was hitting the road.

I'm starting to think that X3 felt dodgy because there was way too much air in the fronts.

[chassis]

Not a GLC, a GLE. M-B has generally low tire pressure specs for ride comfort and grip (safety, lawsuit) reasons. And with low tire pressure comes concomitant reduction in tread life. My travel is either local errands or long distance highway driving, and I prioritize tread life. Grip and ride quality are secondary considerations, bearing in mind that at higher inflation pressures the grip and ride quality will be "good enough" in my view.

The GLC is well known for its crabbing issues caused by M-B's poor choice of Ackermann geometry, and dealers attempt to mitigate complaints with changing tires (customer pays) and reducing tire pressure.

[BobsM3Coupe]

Originally Posted by chassis

I don't think 50psi is the normal pressure. I intentionally air up to 50psi because it doesn't hurt ride quality (my opinion) and increases tread life. German vehicles' air pressure specs are generally oriented towards ride quality and maximum grip. Max grip can be viewed as higher safety and may lead to fewer lawsuits for the manufacturer. Ride quality means fewer complaints from new owners after the first pothole.

However, tire wear suffers at the OEM tire pressure spec.

50psi???
You do know that you are not supposed to put more psi's in a tire than than the manufacturer states on the sidewall. I doubt your sidewall says 50 or more when the tire is cold.
On a nice hot day traveling at highway speeds, you're just asking for a blowout.

[Alias1431]

Originally Posted by BobsM3Coupe

50psi???
You do know that you are not supposed to put more psi's in a tire than than the manufacturer states on the sidewall. I doubt your sidewall says 50 or more when the tire is cold.
On a nice hot day traveling at highway speeds, you're just asking for a blowout.

Agreed. 50 PSI is likely the max.



https://www.tirerack.com/tires/tiret...jsp?techid=301

See above for a loose idea of how max speed can impact PSI recommendation.

[mariopl]

Same here. X4 X30i - ultra sensitive to windy weather on highway. Can barely drive with high speeds.

[KowalskiBMW13]

Same here. I’m right there with you. Reviving an old thread. I’m on a hunt to try and make this thing stable.

[Oswego79]

Wife has a 21 X3 and I have 22 M40i. The cars are just not fun driving on the highway when it is windy. Constantly correcting the steering to stay between the lines. I was wondering if it had to do with the RF tires which have stiffer side walls. My Ram PU rode perfect compared to the X3.

[Lady Jane]

The sidewalls of my staggered summer P-Zeros indicate 50 psi max.

[ContactPatch]

My X3 M40i is "stable" in any crosswind. My first drive was through the Columbia River Gorge (wind surfing capital) the winds were about 50mph for about 45 miles, the X3 was brilliant. I was crushing the winds at 80mph, no drift, no buffeting, and zero wind noise.

[RoundelM3]

Originally Posted by agentorange

Had a loaner X3 yesterday. Sdrive, 18" wheels, 38 PSI showing all round on the pressure monitor (sigh). Anyway, twice on freeways here in Vegas we had a touch of crosswind and the thing went into greasy weasel mode. Only time I've felt worse in an SUV was when the alignment went out on the wife's GLC. FFS, my 2005 Xterra on 75 profile boots was more stable in a straight line.

The X3 drove fine so long as there was no wind. Anybody else noticed this? Could it be the caster is off or some such?

Nope - not on my '22 G01 sDrive30i. It has M-Sport and 20" wheels, but not sure how much of a difference that makes. 6K miles so far without a hiccup.

[lfdal54]

Front and rear are usually about 3psi different, front lower, rear higher. In mine, the typical numbers are 34F and 37R. Factory 19" rims with RFTs.

[KowalskiBMW13]

Yeah this is a common complaint. I’m going after a new alignment next. Turning off the intelligent safety and putting it in traction or dcs off mode helps since it defeats all steering intervention. Otherwise it’s all over the road even in mild winds. Higher psi helps but then the car with the standard m-sport suspension becomes so brittle it detracts from the comfy experience. Owned 3 Bimmers and loaned countless. This is a new thing once they started EPS.

[Gritty]

i've owned the X3 for 8 months and haven't noticed this issue. Running non run flat Continental all season tires at recommended psi.

[agentorange]

Originally Posted by Gritty

i've owned the X3 for 8 months and haven't noticed this issue. Running non run flat Continental all season tires at recommended psi.

Reviving a semi-zombie thread. I claim OP's privilege.

I'm thinking that an sDrive with the 2.0 motor has a lot less weight up front than the M4.0i models some of you seem to have. More weight up front makes most vehicles more stable, it puts the center of gravity further forward of the center of pressure. Also, aren't all the M40i X3s in the US fitted with all wheel drive? That's even more weight up front.

Tire pressure is a thorny subject. I must admit that several of the vehicles I have owned in the US in the last 25 years have recommended pressures that give marginal straight line stability. Sometimes it's the OEM tires. My Xterra was like that, as is my ML350 Bluetec on 19' AMG wheels. We took a road trip around Christmas and upping the pressures from 35 all round to 38 made a HUGE difference in highway stability. Mind you, I think I'll try 37 in the front next time to ease the impact of potholes on the steering parts.