I used one once for about 150 miles and ran it over 50mph as well.

That is recomended use not to go over 50 mph because the car reacts differently with the spare on it (narrow ass POS).

My recomendation is to put it on the rear and a good tire on the fron if you are going to be driving on it at all because your car will pull hard to the side with the good tire on it.....and if it does happen to blow on you its better to have a rear tire go than a front tire.