Tire pressure for Winter Tires

bensanford · 11-10-2021, 11:49 AM

My 230i was delivered with staggered 18" summer performance tires, 225/40 ZR 40 in front, and 245/35 ZR 18XL in the rear with recommended pressures of 32 in front and 38 in rear.

I have winter snow tires that are 225/45 R17 on all 4 wheels, and I'm wondering about what the pressure should be for them. Thanks

aerobod · 11-10-2021, 01:12 PM

If the tyres are extra load rated (XL), you may want to drop the pressure by 2 or 3 PSI, if standard load rated (SL) the same as the summer tyres would be appropriate. Keep an eye on the tyre wear pattern, the fronts may be close to the needed pressure, but the rears may need to be at a lower pressure to avoid excessive wear of the centre of the tread if you don't have a full passenger load much of the time.

I run my 225/45-18 Pirelli Sottozero 3 XL winter tyres (higher profile than recommended) at 33 PSI all around.

Heitzer · 11-11-2021, 07:23 AM

That's really good advice aerobod. I had issues with excessive wear in the center with Michelin PA4s. It was very pronounced on 8 inch wheels with 255/35/18 PA4s.

Last winter I mounted the PA4s on a little wider 8.5 inch wheel assuming this would be the main reason for the excessive wear which I don't see on summer tires (245/35/18). I didn't know XL rated tires can handle lower tire pressures. Hope that works even on shitty roads. I'll try this for this season.

My winter tires only last 15k miles. I have the LSD with higher final drive ratio which doesn't help I suppose with wear in the center.

11-10-2021, 11:49 AM	#1
bensanford Private 32 Rep 90 Posts Drives: Grey '18 230i & Grey '21 330ix Join Date: Jun 2017 Location: Falls Church, VA iTrader: (0)	Tire pressure for Winter Tires My 230i was delivered with staggered 18" summer performance tires, 225/40 ZR 40 in front, and 245/35 ZR 18XL in the rear with recommended pressures of 32 in front and 38 in rear. I have winter snow tires that are 225/45 R17 on all 4 wheels, and I'm wondering about what the pressure should be for them. Thanks __________________ __________________________________________ '18 m230i, Mineral Grey, MT, M-sport, Track Handling, Premium, H-K audio, CarPlay, no Moonroof, '21 m330ix, Mineral Gray, Navi, Driver Assist, Park Assist, 19' orbit grey wheels (wife's car)
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11-10-2021, 01:12 PM	#2
aerobod Car Geek 3612 Rep 3,578 Posts Drives: Caterham R500, M2-G87, Macan S Join Date: Mar 2008 Location: Calgary iTrader: (0)	If the tyres are extra load rated (XL), you may want to drop the pressure by 2 or 3 PSI, if standard load rated (SL) the same as the summer tyres would be appropriate. Keep an eye on the tyre wear pattern, the fronts may be close to the needed pressure, but the rears may need to be at a lower pressure to avoid excessive wear of the centre of the tread if you don't have a full passenger load much of the time. I run my 225/45-18 Pirelli Sottozero 3 XL winter tyres (higher profile than recommended) at 33 PSI all around.
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11-11-2021, 07:23 AM	#3
Heitzer Private First Class 103 Rep 130 Posts Drives: M235i; BMW S1000RR Join Date: Feb 2012 Location: MA iTrader: (0)	That's really good advice aerobod. I had issues with excessive wear in the center with Michelin PA4s. It was very pronounced on 8 inch wheels with 255/35/18 PA4s. Last winter I mounted the PA4s on a little wider 8.5 inch wheel assuming this would be the main reason for the excessive wear which I don't see on summer tires (245/35/18). I didn't know XL rated tires can handle lower tire pressures. Hope that works even on shitty roads. I'll try this for this season. My winter tires only last 15k miles. I have the LSD with higher final drive ratio which doesn't help I suppose with wear in the center. __________________ [FONT="Arial"] M235i 6 speed, MGM. Wavetrac LSD with altered final drive ratio, MPE, MPK Airbox, side skirts, diffuser, Dinan springs, LCAs.
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