Maybe you are bored with your steel wheels or your existing alloys are looking a little tired. New wheels can make or break a car – but before you choose a style you need to know what will and won’t fit your car. Suzanne Keane guides you through the maze that is the perfect wheels
The first step to deciding on your new wheels is to take off one of your existing wheels and look at the back of it to see if anything is stamped on it. You may see something like this “7J x 17 H2 ET35”.
7J – this is the width of the wheel, in this case 7 inches
17 – this is the wheel diameter in inches (you will also be able to tell this from your tyres)
H2 – Means the wheel is designed for taking “h” rated tyres
ET35 – This is the offset of the wheel, which is explained below.
If you decide to change the diameter of the wheels it’s important to check that the rolling radius with your new tyres will match your existing rolling radius (this can affect the readings on your speedometer) – you can check this by using online calculators like this one.
The 3 most important things you need for choosing your alloy wheels are the diameter, in inches, the PCD and the Offset:
PCD – Firstly you need to work out how many wheel studs you have…. but that’s not all! PCD stands for Pitch Circle Diameter which basically means the diameter of the circle of the wheel nuts – so if your car has a PCD of 5×112 wheels that are 5×100 won’t fit. On a 4 stud car you can measure the distance between the centre of opposite wheel nuts, on a 5 stud car this is more difficult but most wheel manufacturers will be able to tell you what PCD your car should be. Keep in mind that not all engine sizes/specs of the same model car will have the same PCD!
ET – This is the offset of the wheel – which is the distance in mm between the centre line of the wheel rim and the centre line of the hub (that the wheel fixes on to). In simple terms this is what decides where the wheel sits in relation to the arches of the car. Get it wrong and you will end up with wheels that scrape off of the suspension or bodywork – or maybe wheels that just won’t turn! You should try to match the offset of the original wheels on the car whenever possible.
Most companies selling alloy wheels wills be able to tell you what will and won’t fit – if you’re not 100% sure about what you need it may be best to go to somewhere that sells and fits as they can ensure the wheels fit correctly before you leave.
If you do have existing alloy wheels it may be worth looking into getting them refurbished instead as a fresh coat of paint and some touch ups can make a huge difference and keep your car at its original spec!
Suzanne Keane
5th April, 2016
