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Marty, BMW Technician
Category: BMW
Satisfied Customers: 54843
Experience:  Bosch Certified Master Technician with over 35 years experience in the automotive industry.
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I have a x5 4.8si with 20" wheels 275/40r20front tyres

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Hi, I have a x5 4.8si with 20" wheels 275/40r20front tyres 315/35r20 rear tyres can i fit 19" wheels with pos. 255x50x19 front and 285x45 x19 rears without altering the gearing Regards

Hi, my name is***** you can downsize to the tires you mentioned without affecting the gearing. The 19" tires are within 1.5% of the old tires in diameter. You will not affect the gearing.

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Customer: replied 12 days ago.
Hi Marty, I have made enquiries about 19" wheels and more than once have been told they will not fit A 4.8si ,will they foul on brakes etc ,Is it just certain wheels ? Mr Gent

Hi Robert, can you post your vin number for me?

Customer: replied 12 days ago.
Hi Marty, WBAFA9205OLE57104 . Bob

Well, when I enter your vin number it only gives me 20" wheels as an option. When I look up the brake calipers they only apply to the 4.8 and the 4.6 engines. It's possible that the calipers are larger and they may interfere when installing 19" wheels. I suggest that you test mount a 19" rim to see if you have the clearance. Originally I was concerned about the gearing. I hadn't considered clearance.

Customer: replied 12 days ago.
Hi Marty , Thanks for that looks like i will have to stick with the 20" wheel , least it will save me money buying others . Bob

You're quite welcome.