Today's family car is a marvel of engineering and technology. Would you believe that the modern family sedan with a six-cylinder engine has more horsepower than most early Corvettes?
The Marvels of New Auto Technology
Commonplace now are computer-controlled components such as ABS (Anti-Lock Braking System) that makes stopping on slick roads safer than ever before, electronic modules to control vehicle stability, and other systems that prepare the vehicle and protect you if they sense an impending crash by increasing brake pressure, pre-tensioning seat belts, or moving head restraints into an optimal position.
Where Does the Lowly Lug Nut Fit into New Auto Technology?
Now even something as old-fashioned as a lug nut has become, in a manner of speaking, high tech.
From the time the wheel was invented, there was a way to fasten it to an axle. From Roman chariots (a la Ben Hur), to Conestoga wagons traveling west, and from wheelbarrows and bicycles to Indy cars (with a single big nut) and NASCAR (with 5 lug nuts, just like most cars on the road today), every wheel in use must be secured in a manner that holds up under all expected stresses, but that can be easily removed for maintenance, repair, or replacement.
Four, Five, Six, or Ten Lug Nuts?
The device that serves this purpose on a car, SUV, or light truck is called a lug nut. Most vehicles have five; some smaller, lighter vehicles may only need four, while larger vans and trucks use six, and heavy, commercial trucks (think semi-tractor-trailers) use ten.
The lug nut is always functional, but it could also be chromed and capped and be decorative, as well. Regardless, they all screw onto a threaded stud. In some cases, such as some Volkswagens and Audis, Mercedes, and BMWs, the lug-bolts are a combined nut and bolt (stud) that screws into the brake rotor or drum to secure the wheel and tire combination.
Using a Star Pattern for Lug Nuts
Almost everyone has heard that you tighten the lug nuts in a "star" pattern, to help them "seat" the wheel properly against the mounting surface. This in itself is very important, because if the lug nuts are tightened while the wheel is improperly placed (not seated flush against the mounting surface), when the wheel eventually pops into place going down the road, some of the lug nuts will be loose. The first result will be the wheel wobbling; after a very short period, the studs will break and the wheel and tire will come off!
There is plenty more important information about lug nut torque - so, keep reading!