HEy Guys I was wanting a spare donut for our c max when we go on long trips but I got to reading post and thought it be better to get a full size to avoid this comment "I didn't come up with this different diameter wheel issue, it would not have occurred to me that a small spare would cause a problem.. This concern is simply because I've read many other Forums about this, Mustang, Fusion, Corvette, etc. Some have brake clearance issues, but all the Ford Forums are concerned about the digital controls for the drive train and damage that can happen, plus the possibility the car's computer will just got into 'limp' mode. I don't really know, just trying to find out because I'd like a spare, if it won't hurt anything when I use it. There is a reason Ford didn't put a spare in these cars, besides weight and cost." What tire do you guys know I could get out of a local salvage yard off a older vechile that would fit the c max for a full size where I dont have to worry about this?