Buying new rims for a car is sometimes costly, but the price on new semi truck rims is absolutely outrageous. You can save hundreds of dollars per wheel simply by going with used ones. That said, not just any rim works, and finding the right rim is difficult if you do not know where to look. Here, find advice on identifying the rims you need, and how to buy them at a steep discount.Getting the right rimBecause most semi truck rims are not made for show like car rims are, they frequently feature generic dimensions. That means that a number of different rims may fit your semi truck. Check the measurements inside one of your existing rims. If you cannot find the information stamped on the wheel, pull a model number for reference. If all else fails, call your dealer to find out what size/type of rims you need before you start shopping.Simply ordering new rims from your dealer is the easiest option, but since dealers charge the OEM rate for rims, this is also the most costly option. Where to look for the best dealBecause complete semi trucks are so rarely scrapped, you can have a hard time finding the rims you need at a scrap or junkyard. Instead, consider contacting independent semi shops to see if they can locate a used rim. Also, eBay is a great resource for finding a compatible rim at a cheap price, but realize that the shipping cost increases your total cost.Getting a good rimOnce you find a used rim that fits your budget and your semi, there are a couple other things to consider before buying. First, lay the wheel flat and look at it from above. Check that the wheel is perfectly round, any wobbles are indicative of bends that can cause trouble on the road. Second, run your hands around the front lip of the rim. While some curb rash is normal, gouges can affect the tire seal, and cause air leaks. Finally, look at the whole wheel to check for cracks. A cracked wheel is a dangerous wheel and not worth the risk regardless of the cost.Buying replacement wheels is not a painful process if you know what to look for, and where to find it. Used rims offer you a cost effective alternative to buying new wheels direct from a dealer.