How much do you know about wheels, rims, and lug nuts? What you don’t know could negatively impact your vehicle’s performance. From the experts at Mavis Tires and Brakes here’s everything you need to know about wheels and rims.
Do you want to know which lug nuts are best for your aftermarket wheels? Do you want to replace your current lug nuts? Either way, there’s a lot you should know about lug nuts before you make your purchase. Here are some lug nut basics to get you started.
Also called lug bolts, lug nuts are the hardware that secures your wheel and tire assembly to your vehicle. Even though they’re small, lug nuts have the critically important task of ensuring your wheel is installed safely and securely.
Lug nuts vary in thread pitch and size, but one of the most crucial differences between lug nut types is the lug nut seat, the contact point where the lug nut meets the wheel. The wheel lug seat and lug nut seat must match, or the lug nuts won’t safely secure your tire and wheel assembly to your vehicle.
There are a wide variety of lug nuts available. Some of the most common lug nut types include:
Conical or tapered seat lugs have a cone-shaped lug seat.
Extended thread (ET) lugs have a conical seat and require a special key for the spline grooves.
Flat seat lugs have a flat, washer-like seat.
Lug bolts have the stud attached and bolt onto the rotor rather than onto a stud. They’re mostly seen on European vehicles such as Volkswagen, Mercedes, BMW, and Audi.
Mag seat lugs feature a flat washer seat with a longer thread area than flat seat lugs.
Small diameter spline drive lugs have a conical seat, are small in diameter, and need a special key to remove them.
Spherical or ball seat lugs have a rounded lug seat.
Turner style lugs have a conical seat, are very small in diameter, and need a special key inserted into the face of the lug nut to remove them.
Lug nuts must be the correct length for your vehicle because lug bolts that are too long can cause movement issues.
In addition to the length, lug nuts must be the correct size to match your vehicle’s requirements. Lug nut sizes are given in two numbers. The first number is the stud’s diameter, and the second is the thread pitch. On standard lug nuts, the thread pitch is the number of threads per inch, while on metric studs, the thread pitch is the distance (in millimeters) between each thread.
For example, a 10mm X 1.25 lug nut has a 10mm diameter with a thread pitch of 1.25 mm. The most common lug nut sizes include:
10mm X 1.25
12mm X 1.25
12mm X 1.50
12mm X 1.75
14mm X 1.25
14mm X 1.5
14mm X 2.0
7/16″ X 20
1/2″ X 20
9/16″ X 18
Most lug nuts are right-handed threaded and follow the “righty tighty, lefty loosey” rule. Left-hand threaded lug nuts are rare and are usually marked with an “L” or “LHT” on the side of the lug nut.
Thread engagement refers to how many complete turns a lug nut makes before it’s tight or how much contact a lug nut has with the stud. If regular lug nuts don’t have enough thread engagement, you may need extended thread (ET) lug nuts – make sure the lug holes in the wheel are wide enough for the extended thread area.
Lug nut torque refers to the amount of force required to tighten lug nuts. Each vehicle has specific torque requirements. Correct lug nut torque, measured in foot-pounds (ft-lbs), ensures a safe, secure fit. Under- or over tightened lug nuts can both cause safety issues.
While most lug nuts have a hex nut shape that fits regular sockets, others require special keys to install or remove them. Whatever type of lug nuts you have, make sure you have the proper tool to remove them so you can change your tire if you get a flat tire.
Aftermarket wheels can add style and performance to your vehicle, but most original equipment lug nuts won’t fit aftermarket wheels, so make sure that you also upgrade to lug nuts that will fit your wheels’ new rims.
If you’re replacing your tires or wheels, you need to know your wheel dimensions and how they affect your vehicle and the way it rides. Also called wheel width, rim width is measured from bead seat to bead seat – the points of contact between your wheels and tires.
Your tire size and rim width must be compatible because the rim width directly impacts your tire’s contact patch. That can alter how your vehicle handles and how the tire interacts with the road.
Because of their flexible construction, most tire sizes work on a small range of rim widths (usually within an inch or two). However, you should stay within the range of approved rim width/tire size combinations determined by the Tire and Rim Association and the European Tire and Rim Technical Organization.
If you keep the same tire size but increase your rim width, the tire will be slightly wider and the sidewall will be tighter. This will provide a faster steering response – but at the expense of a smooth ride. On the other hand, putting the same tire size on a narrower rim will soften up the handling but provide a smoother ride.
You need to understand wheel torque because it’s critical to install wheels safely.
Wheel torque is a rotational force that measures lug nut tightness in foot-pounds (ft-lbs). Each vehicle has its torque requirements.
Mavis Tires and Brakes can check your wheel torque. In fact it’s always a good idea to let Mavis do the checking as we have a wheel installation process that includes multiple steps to installing wheels properly.
Incorrectly tightened lug nuts may cause a wheel to become loose or even come off entirely.
If your steering wheel is off-center when you drive straight, your vehicle pulls to one side, or you notice irregular tire wear, you may need a wheel alignment. But what is a wheel alignment service?
Many things can cause your alignment to get out of whack, but the most common causes are impacts with curbs, potholes, or other objects. Over time, normal wear and tear on your vehicle can also affect your alignment. A few examples include:
Worn tire rods
Weak or worn springs
Worn ball joints
A wheel alignment service adjusts many settings to get a vehicle back into proper alignment: camber, caster, toe, and ride height are just a few.
Camber is a tire’s outward or inward tilt when viewed from the front of a vehicle. Positive camber refers to a tire tilted out, and negative camber refers to a tire tilted in. Camber has the most extensive range of recommended settings to accommodate various vehicle handling characteristics. The more aggressively a driver takes corners, the higher the negative camber their vehicle should have.
Caster refers to the angle of the steering axis – the suspension component that supports the wheel and tire assembly. A properly aligned caster contributes to high-speed stability and steering feel.
Toe is a tire’s inward or outward tilt when viewed from above. Front-wheel drive vehicles may need a compensating toe-out setting on the front axle because the front wheels pull toward each other while the vehicle moves. Rear-wheel drive vehicles may have a toe-in setting on the front axle because those wheels pull away from each other while accelerating.
Ride height refers to the distance between the vehicle frame and the road and provides reference points for the rest of the alignment measurements. If you lift or lower your vehicle, you will need a wheel alignment after the customization is finished.