I want bigger wheels. How big can I go?

That depends on your car and the amount of work you're prepared to put in. Generally, most cars will be able to handle an increase in wheel size of up to four inches, with no need for any modifications. However, this degree of upsizing should be coupled with a lower profile tyre, to make sure the overall radius of the wheel/tyre is the same as the car's original equipment specifications. This means that the car's overall gearing will be unchanged and the speedometer will still be accurate.

What options give the same rolling radius?

As a rough rule of thumb, the following combinations give approximately the same rolling radius for the overall wheel/tyre combination:
195/65R15 Rolling diameter 645mm
205/55R16 Rolling diameter 642mm
225/45R17 Rolling diameter 642mm
225/40R18 Rolling diameter 645mm
225/35R18 Rolling diameter 647mm

Should I go bigger on the size or the width?

Keeping the same width of the wheel and tyre package while increasing the diameter of the wheel, with an accompanying lower-profile tyre to compensate, means that the car will look better and you would see the benefits of lower profile tyres, in terms of grip and steering response. It also means that generally, since the overall wheel/tyre package is the same size as the original equipment, there wouldn't be any real problems with tyres hitting the wheelarches or changes in your car's handling.

What about if I want really big wheels?

Then you may need to look at modifying your wheel arches to prevent contact, particularly when turning the steering. You can usually get a bodyshop to either roll or cut the inner lip of the wheelarch away to give more clearance - rolling tends to keep inherent strength in the arch, while cutting tends to lose it.

How can I find out what size wheels fit my car?

Contact your nearest TSW dealers, whose details can be found on the website, under 'UK Dealers'. They will be able to tell you the best size and style of wheel for your car, as well as recommend the best tyre to go with your new rims.

What is the offset of a wheel?

The offset is the distance from the mounting face of the wheel, where it mounts against the wheel hub, and the centreline of the wheel's width. It will be expressed as a distance, usually in mm and called ET.

Why is offset important?

When a car is designed, the suspension is configured in a certain way, which uses wheels with a certain offset. If this offset changes, then the distance between the mounting face and the centre of the wheel changes and this can affect the handling of the car. One situation is tram-lining, where the car wanders, following imperfections in the road surface, rather than running straight. Another possible situation is torque steer, where the steering pulls from one side to the other under acceleration.

What is the PCD?

PCD stands for Pitch Circle Diameter and is a measure of the wheel stud/bolt hole locations. The PCD is a circle with its centre at the centre of the face of the wheel. The centres of the mounting holes are equally spaced around this circle. So for example, a 4x100mm PCD means four mounting holes, equally spaced around a 100mm diameter circle form the centre of the wheel.

What does a Spigot Ring do?

This is a plastic ring that sits inside the alloy wheel, locating it centrally on the car's wheel hub. The spigot doesn't form part of the mechanical join between the car and the wheel, that's done by the wheel nuts/studs. The Spigot simply makes sure that the wheel is located centrally on the hub. If it wasn't, the wheel nuts/studs would have to centre the wheel and if the wheel wasn't perfectly central on the hub, there could be possible vibration and balance problems.

If I've fitted new wheels and tyres, what pressure should I run?

The general rule is to keep running the same pressure as the manufacturer recommends for the original equipment, as it's this which supports the weight of the car.

What's the warranty on TSW wheels?

TSW wheels have a lifetime warranty on the structure of the wheel itself, while there is a one-year warranty on the coating or paint finish. Unfortunately, TSW cannot offer a warranty on wear and tear or accidental damage that occurs through normal use.