Just bought a 2012 ML350. The front tires have less tread than the rears. Which end wears faster? Not sure if I should rotate or leave the tires alone.

 

Normally the drive tires on most vehicles wear faster, but being all-wheel drive all 4 tires should wear the same.Is the wear pattern of the tires in question wearing evenly all the way across-more on the outside-more on the inside.Tire pressure to low or high can cause premature wear.Turn your tires to far-left then far-right and take couple of pics with your phone.Excessive wear on the inside or outside could be due to inner or outer tie rods with excessive wear/slack in them.How many miles are on it dave? Being a 2012 unless its has high mileage i wouldnt think u would have any front end parts worn out yet..Could just need a 4 wheel alignment.Post some pics of the tire wear and we can narrow it as to the cause.Normally when tires are balanced and rotated the best tires go to the front /steering