I`ve only had the X5 10 weeks 64k on the clock and yes UK gallons @ roughly £6.00 per gallon! need a petrol tanker running behind me at this rate.
Checked HT leads and plugs which give very good sparks, no leads shorting/bridging.
Also have the dreaded parasitic battery drain, got to charge battery every day or two, renewed battery, renewed fsu and disconnected retro bluetooth, tbh this is the worse car I have ever had for faults! BMW have in my opinion went downhill for reliability, this is my 3rd Beamer and my last