Wheels And Tyres

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When it comes to wheels and tyres, a lot of Yaris owners are a little unsure of what to buy, so here is a guide to help you buy the correct wheels/tyres for your Yaris.

Wheels come in lots of different fitments to fit different cars, the fitment for the Yaris is as follows...

PDC 4x100.. (This means 4 holes spaced 100mm apart for the wheel nuts)

ET 35 - 45 (minimum = ET35, maximum = ET45).. this is what is known as the offset.

Centre Bore - 54mm (With most aftermarket alloys, you will also be supplied with centralizing rings...see below)

J size - This is the width of the wheel.

Example of a typical wheel size for the Yaris - PDC 4x100 ET 38, 16 x 7J

Offset Explained

The offset is the distance between the mounting surface and the centre line of the wheel, it is always measured in millimetres.

If you sit the wheel down on a flat surface and measure the width of the wheel, divide it by 2, you get the centre line. The offset is then the difference between this centre line and the point in which the wheel comes into contact with the hub (mounting surface). The bigger the offset, the closer it will sit to the strut, the smaller the offset, the closer it will sit to the arch.

Example :- ET35 will sit closer to the wheel arch than ET45.

PDC Eplained

The PDC is the distance in millimeters from the centre of a stud hole to the centre of the stud hole diagonally opposite.(for 4 stud wheels)

Centralizing Rings

These are a very important, and often overlooked part of buying aftermarket alloy wheels. Centralizing Rings are the plastic/metal rings, that should get supplied with your wheels, that will convert the Bore Hole of the wheel (the hole in the centre) to the same size as the hub.

If the Centralizing Rings are not fitted you have 2 problems..

1.) The wheel won't be centred on the hub properly, resulting in vibration through the steering wheel, this feels excactly the same as driving with wheels that are out of balance.

2.) This is a problem that most people won't even think of, if the Centralizing Rings are missing, the wheel will have no support from the hub, this means that the full weight of your car is only being supported by the wheel nuts, which they are NOT designed to do.

Will my tyres rub on the arches?

The question that is most commonly asked is wheather or not the tyres will hit the bodywork of the car. This will depend on what Diameter and Width of wheel you buy, AND if your car has been lowered.

15"- with 195/50x15 will fit without arch modifications (195/45x15 if lowering is planned) PDC 4x100, 15x7J, ET38, would be best

16" with 195/45x16 will fit without arch modifications, (if lowered by more that 30mm some arch work may be required on some models) PDC 4x100, 16x7J, ET38, would be best

17" with 205/40x17 arch modifications WILL be required on T-Sport Models and ALL models which are lower than a base model Yaris. APDC 4x100, 17x7J, ET42, would be best (A base model Yaris will take 17" and 205/40x17 tyres without arch work being done, as long as the the car isn't lowered)

Tyre sidewall information

It's confusing isn't it? All numbers, letters, symbols, mysterious codes. Actually, most of that information is surplus to what you need to know. So here's the important stuff:

A:- Manufacturers or brand name, and commercial name or identity.

B & J:-Tyre size, construction and speed rating designations. Tubeless designates a tyre which requires no inner tube. See tyre sizes and speed ratings below.

C:- Denotes type of tyre construction.

D:- M&S denotes a tyre designed for mud and snow. Reinforced marking only where applicable.

E:- Load and pressure marking requirement (not applicable in the UK). These go from a load index of 50 (190kg) up to an index of 169 (5800kg).

F:- ECE (not EEC) type approval mark and number.

G:- North American Dept of Transport compliance symbols and identification numbers.

H:- Country of manufacture.

Also on the sidewall, you might find the following info embossed in the rubber.

The temperature rating - an indicator of how well the tyre withstands heat buildup. "A" is the highest rating; "C" is the lowest.

The traction rating - an indicator of how well the tyre is capable of stopping on wet pavement. "A" is the highest rating; "C" is the lowest.

The tread-wear rating - a comparative rating for the useful life of the tyre's tread. A tire with a tread-wear rating of 200, for example, could be expected to last twice as long as one with a rating of 100. Tread-wear grades typically range between 60 and 600 in 20-point increments. It is important to consider that this is a relative indicator, and the actual life of a tyre's tread will be affected by quality of road surfaces, type of driving, correct tyre inflation, proper wheel alignment and other variable factors. In other words, don't think that a tread-wear rating of 100 means a 30,000 mile tyre.

Wheel Torque Settings

103 Nm or 75.97 ft.lbs.

This is by no means a definative guide, CHECK WITH THE RETAILER before you buy your wheels and Tyres There are a lot of variables from car to car, even same models, each car is slightly different.