Looking for new alloy wheels for your ride? There is always a time for a car owner when he/she decides to replace the current alloy wheels with new ones for one reason or another. Since i have been known as the alloy wheel expert, people always ask me about fitment, offset, bolt pattern and so on.
Unfortunately, it is not as easy as it sounds. Many people think that all alloy wheels will fit their cars and they search the internet for second hand alloys without checking their wheel specs. Over the years, I have met quite a lot people who bought alloy wheels and ended up wasting their money on some useless, wrong wheels for their cars.
There are a few technical issues you have to be aware of before going on a hunt for some cheap alloy wheels.
First of all, note that every car make has its own unique wheel specs which means not all rims will fit your car.
Secondly, do your homework and find these specs in your manual book. It will give you the technical specs for your car make and model.
Your new rims must have the same bolt pattern with your current ones. Bolt pattern also known as stud pattern or PCD (Pitch Circle Diameter)is the measurement of the spacing of the mounting holes in your alloys and the bolt holes on the hubs of your car. Do not forget, PCDs have to match exactly for a proper fitment.
Next one is Offset which is the distance in mm between the mounting face at the back of the wheel and its centre line. This is expressed as ET which comes from the German word “Einpresstiefe”, meaning ‘insertion depth’. Getting the correct offset is important to have a proper look and also to stop the wheels and tyres fouling the inner arches or suspension components. Each car has its optimum offset and a tolerance range within which the offset can be for the wheel to fit the car properly.
For example a 2009 model Ford Focus will require 15 inch alloy wheels with an offset range between 38-52. If you buy above or below these specs, then you are likely to have problems tyres scrubbing the wheel arches or suspension system. In both cases, problems will occur in handling and driving. Must be avoided!
Centre bore size is another important issue for new wheels. This is the diameter of the hole in the back that fits onto the flange on the car’s hub which is known as the centre bore. Once again,your car has its own centre bore size such as 63.4 For Fords,64.1 for Hondas and 57.1 for VW wheels. Aftermarket wheels are generally manufactured in high sizes such as 67.1. To reduce 67.1 to your centre bore size, you will need spigot rings to have the proper fitment. Without these rings, new wheels will not fit on the hub properly and will cause vibration on the car. It will be a very uncomfortable ride so make sure you have the correct size rings with the wheels.
These are the basic technical details for an alloy wheel. Whether you are buying a new set or a second-hand, please make sure you are getting the correct application. After all, alloy wheels do not come cheap and you would not want to see your new rims sitting in your living room or garage due to wrong application.