How does having the wrong sized tires on rear of car affect safety?

A shop put P205/65/R15 tires on the rear of my (front wheel drive) Mazda 626, when the recommended size, and the size of the current front tires is P205/55/R15. I did not notice until a couple of days after driving home (65 miles). What are the effects, and in particular the dangers (e.g. braking) of having different sized tires on the front and rear?|||The wheel size is just as important as the tire size. Some sport cars like BMW M-3, Porsche 911, and Ferrari come with wider rear wheels and lower profile tires on the drive wheels. The lower profile puts more rubber on the ground and theoretically achieves a better bite on most any kind of road. The 205 dimention means 205 mm from tire bead diagonally to the opposite inside the sidewall adjacent to the inboard tread. The 55 or 65 means the aspect ratio in per cent: vertical sidewall measure to horizontal tire thickness. The R-15 means a radiial tire on a 15 inch diameter wheel. The wrong size tires will likely effect the car's handling. The government mandates that all tires sold in the US have a UTOG rating that defines the test traction, the traction in wet, and the maximum speed in Km per hour. EX: P205/55/R15.|||none.. really is about the same maybe a half inch short of being the same... nothing to worry about that way... what your thinking about is or woul dbe bad is taller and shorter tire which you dont have.... 205 is how tall 55 is how wide the 15 is the size of wheel your fine... a lot of times between makers they will be the same.... most tire compaines makes their tire a bit different ... ive been doing it 30 yrs.. you wouldnt want a 215 and a 205 together or a 195 and a 205 now that would cause a strain on other parts... if you take a good look.. not at the size number but the tire itself you might be able to see they are the same or about the same looking... you could jack it up and remove it and but side by side to see also.. .long as they are the same size 205 your fine... well if you line up five differant brands all the same size there will differant in the sizes by looks.... try it and see|||It should not effect the overall safety as long as they were put on the rear but I would just go back and tell them to put the correct size on because you will need to balance and rotate them and then what will you do.......|||It will be slightly bigger, which will affect your balance of the car. Safety wise it may not be a big factor, but i would expect a pull in one direction or another as the ca tries to turn slightly with the wheel in nuetral position. It would be best to have that changed.The 65 is the aspect ration of the sidewall, and since the 205 stayed the same, on the same size (15) wheel you have a slighlty taller tire than the other three. When you rotae you may have an issue in sterring even more.|||None probably but why not just get the reccomended size?