In order to make a proper and safe wheel purchase, in addition to the aesthetic factor, we should take into account a significant number of other factors that are presented below.

Wheel Size

First, let's explain their most common characteristic, the size, which follows a notation of the type 7x14. The number 7 refers to the distance (measured in inches) between the ends of the wheel, where the tire (rim) "sits", and not the overall width of the wheel, which is larger. While the number 14 describes the diameter of the wheel.

PCD (Pitch Circle Diameter)

Starting from the obvious, we need to take into account the number of bolts that each wheel accepts. It is obvious that a 4-bolt wheel cannot be combined with a hub that is designed for 5 bolts. The hub is the point where the wheel is screwed on and essentially serves as the connecting link between the wheel and the car.

In addition to the number of holes we mentioned earlier, we should also consider their distance from each other so that the wheel can be screwed on.

These two characteristics are described by the PCD (Pitch Circle Diameter) number, which follows the notation of the type 5X114.42. Specifically, a wheel with a PCD of 5X114.42 has 5 holes with a distance between them defined by a circle with a diameter of 114.42 mm (red circle).

Offset

The distance in mm between the vertical axes shown in the figure below (Red and Blue) is considered of crucial importance. This characteristic determines the behavior of the suspension and the alignment of the steering wheel.

The red axis is imaginary and passes through the center of the tire tread. The blue axis represents the point where the rim joins the body. The distance between them is called offset. In case (1), where the red axis is to the right of the blue one, we say that we have positive offset or inset, while in case (2), where the red axis is to the left of the blue one, we say that we have negative offset or outset. Usually, the deviation allowed from the factory specifications, without any problem being detected, is in the range of 5mm to 7mm. Since in some cases the length is given in inches, we remind you that 1 inch equals 25.4mm. On some rims the notation “ET45” is encountered, which describes an inset of 45mm.

Weight

The weight of the wheel is particularly important for the road behavior of our car, as it is the only weight that is not supported by the suspension but "hangs" on it. Reducing weight will provide us with better road behavior by assisting in the immediate response of the suspension to road irregularities, resulting in better grip for the car.

Construction Material

The construction material of the wheel is important as it is related to both its weight and its strength. Most wheels nowadays are made of lightweight aluminum, offering the car reduced weight and greater shock absorption. Unlike other construction materials, aluminum is more vulnerable to collisions with sidewalks and potholes due to its elasticity, making the wheels more prone to distortion. Magnesium is one of the best materials for wheel construction as it offers greater durability and is lighter, but its price is relatively higher compared to other materials.

The red axis is imaginary and passes through the center of the tire tread. The blue axis represents the point where the rim joins the body. The distance between them is called offset. In case (1), where the red axis is to the right of the blue one, we say that we have positive offset or inset, while in case (2), where the red axis is to the left of the blue one, we say that we have negative offset or outset. Usually, the deviation allowed from the factory specifications, without any problem being detected, is in the range of 5mm to 7mm. Since in some cases the length is given in inches, we remind you that 1 inch equals 25.4mm. On some rims the notation “ET45” is encountered, which describes an inset of 45mm.