Can you mix tires brand between front and back on the x5?
 

The two rear tires are brand new.

The front are pretty bad the thread is showing on one.

The Michelin that are on the x5 are discontinued. Can I use different tires on the front and leave the one on the back?

Are the one in the back discontinue or the front? If the back are brand new you should be able to do an internet search and find the same tires for the front.

They are the same as the front they are the michelin energy hde called michelin last week and they said they are discontinued 2013 and they are trying to locate some

Most tire and vehicle manufacturers will say don't mix them, but I've seen so many tires mixed at the track that I think you can as long as you keep the sizes right and you keep the same tires on both sides (in other words, fronts match each other and rears match each other). With that much cord showing, I would be surprised if you didn't need rears too (check the inside tread), and if only one has cord showing maybe you need an alignment too.

The rear have like 12k on them the front are shot they are the original that came with the car.

have to agree as long as the tire sizes are adhered too then why not, but try to keep the same tread and tire on each axle......I love confusing people with my tire wear story, and here is my story I had the same wear at the rear as you, the garages could not dial out camber and couldnt see any worn suspension componenets and I really didnt want to start changing out parts in the hope they would hit on the problem and resolve it by chance. Was fed up of the rather stiff ride the OEM 19" alloys/wheels gave me, so I picked up a set of 17" OEM (same as the alloy and tire thats used for a spare)...softer ride and better for the crap roads out here......in addition to this benefit there is NO more uneven wear at rear or anywhere for that matter:confused:

(PS i also replaced the tires at rear when i had 19" alloys same wear appeared tooooo soon, so the 17" despite looking a bit small are fine)

On all wheel drive cars, the tread pattern has to be same on all 4 tires for AWD to perform properly.

What does a difference in tread pattern front to rear have to do with AWD proper performance?

Tread pattern doesn't matter for awd, just circumference matters.

Tread pattern and thus handling characteristics matters for DSC.

Even still, I'd imagine that as long as you pick a tire with similar specs, you'd be just fine. I wouldn't mix high performance summer tires with all-terrain mud sloggers, but 2 pairs of the same type ought to be alright.

The DSC can't be THAT sensitive... if you think about it, 99% of the time, all 4 tires are on a patch of roadway that varies a lot more than the tires themselves.. bits of gravel and sand, uneven wear, cracks, etc and it copes with that.