My battery died in the XF. I have an optima G34 that is 11 yrs old, sat in a mustang outside during that time only used three starts in 2006. I grabbed it today and it still had a 7.2 V charge, put it on the charger and it charged to 12 quick. My question is, do you think its safe to use on the XF, with the car being so finicky with electronics, I thought I would ask you all. Thanks