Home FAQ

What do the wheels sizes mean?

Wheel diameter

The diameter of the wheel, referred to in inches, determines the tire sizes that can be installed. It is calculated by measuring the distance between the points where the beads of the tire sit on the wheel. This measurement does not include the rim flange.

Wheel width

The wheel width, referred to in inches, is measured from the inside of one wheel flange to another. It dictates the tire sizes that fit on the wheel. The ideal situation is when the rim width and the tire tread width are the same, as the shoulders are straight and there is full grip on the ground.


The ET (also known as offset), measured in millimeters, can be negative or positive, and is the distance from the hub-mounting surface to the rim's true centerline. When the hub-mounting surface is closer to the outside edge of the wheel the ET is positive; when the hub-mounting surface is closer to the inside edge of the wheel and wheel sticks outwards more than inwards, the ET is negative. When the hub-mounting surface is exactly in the middle, the ET is 0. Therefore, given two wheels with the same width, the one with the lower ET will be closer to edge of the fender, and the one with the higher ET will tuck inside the fender and be closer to the suspension components.

Bolt pattern

The bolt pattern determines the number of the mounting holes to allow the wheel to be bolted to the hub of the car.


The PCD (Pitch Circle Diameter) expressed in millimeters, indicates the diameter of the circle determined by the positions of the bolts, lying the center of every bolt on the circumference of the circle.


The CB (centerbore) of a wheel is the size of the hole in the back of the wheel that centers it over the mounting hub of the car. It is important to have a centerbore that matches exactly with the hub to reduce vibration by keeping the wheel centered.

What do the bolts & nuts sizes mean?


The thread is essential to determine the match between the two fastening elements of the wheel (nut and stud, or bolt and wheel hub). It is indicated with a code composed of three elements: the first letter indicates the type of thread, the first number indicates the nominal diameter (the ideal maximum thread diameter for external thread), the second number indicates the pitch (the distance from the crest of one thread to the next). For example, M12x1.5 indicates the ISO metric thread (symmetric V-shaped thread with the flanks of the V having an angle of 60° to each other) with a nominal diameter of 12 mm and a pitch of 12.5 mm.


Hex indicates the distance in mm between the two opposite sides of the hexagonal head of the nut or bolt. This measurement determines that of the wrench to be used for tightening.

Allen key

The Allen key is a tool used to drive bolts and screws with hexagonal sockets in their heads. The size, expressed in mm, determines the distance between the two opposite sides of the hexagon.


The seat indicates the matching between the fastener (bolt or nut) and the wheel. It can be of different types: flat, tapered, spherical. For a correct installation it is necessary that the bolt or the nut has the same seat of the fixing holes of the wheel: the use of inadequate bolts and nuts can cause damages to the wheel and jeopardize the safety of the user. Not all the spherical and tapered seats are the same, EVO Corse manages the matching and provides the instructions as well as the bolts & nuts suitable for fixing.


The end of a lug nut can be open or closed. Open-end lug nuts are mainly recommended for race cars, as tire changes are frequent. For road cars, instead, it is recommended to use closed-end lug nuts, which protect the stud from rubbles and atmospheric agents that could damage it or compromise the thread.

How are the EVO Corse wheels manufactured?


The EVO Corse wheels are made of g-AlSi7, an aluminum and silicon alloy that lends itself very well to heat treatment, a process that improves mechanical performance by 20% and which makes it currently the best and most used foundry alloy.

Low pressure die casting

It is the most used casting technique for g-AlSi7 alloys. The liquid aluminum at about 700 ° is injected into the mold with a pressure of about 1.2 / 1.5 Bar. The liquid aluminum then, subjected to pressure, fills all the areas of the mold and takes the shape of the wheel.

Made in Italy

All the EVO Corse are entirely manufactured in Italy, in the the processing plants of Castelfranco Veneto headquarters and of the commercial partners.

What is the suggested fastening torque for fixing the wheels?

The suggested fastening torque is approximately 120 Nm for cars and 140 Nm for SUVs, minivans and off-road cars (follow the car manufacturer instructions to know the correct fastening torque).


The compatibility of the hub centric rings is given by the internal diameter, if this corresponds to the diameter of the car hub, then it is compatible. WARNING: it is essential to make sure that the ring is compatible with the wheel to be installed, i.e. the outer diameter of the ring must fit perfectly the central hole (CB) of the rim.