My understanding is the recommended size is 255/50/19 all round on the E70, so its not as if these are massively bigger 30mm in width on rear tyres only.
PS can't remember the last time I saw an X5 upside down in a ditch whether on winters or summers
Like you say horses for courses
Actually I've just checked BMW website and for the E70 X5 the option is shown below
19" Y-Spoke 211
Winter complete wheel set
axle Rim-dimension Tyre-dimension EU-Tyre Label Tyre manufacturer Tyre Type Part number
Front
Rear 9Jx19
9Jx19 255/50R19 107V XL
255/50R19 107V XL
Goodyear Ultra Grip ROF RSC 0445762
Prices include VAT at 20%. Please note that model restrictions may apply and that supplementary parts may also be required, dependent on model. For further information, please contact your preferred BMW Dealer
The wheel/tyre combination may be registration relevant. Please check the CoC of your car, if the wheel/tyre combination is registration relevant. For more information, please contact your BMW service partner.
All the tyres have been specially developed for BMW models and have the BMW star marking.
RSC = Runflat tyre
RDC = Tyre with Tyre Pressure control system
Contact dealer
Retail Price: £ 2.360,00
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http://www.bmw.co.uk/en_GB/topics/owner ... g.html/url]