Why don't manufacturers put racing-style single wheel lock nuts on road cars?

If you've ever had to change out to a spare tyre, you'll know that undoing the lug nuts is a genuine pain. You'd also be thinking to yourself, why not just have a single wheel lock so that I only have to undo one lug nut?!

While single wheel locks do look rather futuristic, it's actually a really old technology, dating back to the early 1900s. Today, a single wheel lock system is the preserve of exotic sports cars (like the Porsche 911 GT3) and racing applications such as Formula One cars.

So, why then do we not see single wheel lock systems on more regular road cars? Surely, it's the better, easier solution for everyone. Why persist with a 4/5 wheel lock arrangement? Isn't it more of a hassle? Fret not, let's satiate your curiosity. 

In racing, speed matters

You probably have seen Formula One pitstops being executed flawlessly in next to no time (Red Bull Racing are the current record-holders, with a 1.82-second pitstop, watch the video below). In racing, time is of the essence, hence the need for a single, center wheel lock to execute lightning-fast tyre changes.

On road cars, record-breaking pitstops are.... not necessary. Your tyre foreman can take his time to take out the 4 or 5 lug nuts on each wheel, put some grease on them, and resintall them while he has his afternoon teh tarik. 

Point is, a single lock system is kinda overkill for regular road cars. It serves no purpose other than looking really magnificent.

Even if you insist on having a car with single wheel locks, the kind of speedy tyre changes you see on Formula One cars isn't possible. Why? Because you'd need to hire 4 persons to change the wheels simultaneously. It's impractical and expensive. Speaking of expensive....

They're incredibly hard to work on, and expensive

Because a single wheel lock now has to bear the mounting load of the entire wheel (instead of 4 or 5 locks sharing the load), the torque required to remove/install a single wheel lock is incredibly high.

Which means, if you have no power tools available to you when you change a single lock-equipped car, you're going to have a bad time. Doing it alone? Forget it. Just watch the video below (jump to the 4-minute mark).

If you don't fancy manual labour, you can always use power tools right? Well, you'd imagine that the bespoke power tools needed for single wheel locks wouldn't be cheap, and you'd be right. 

Worse still, you somehow lose one of these wheel locks. We'd wager that the replacement cost would make both you and your credit card company tear a little, for different reasons of course.

What they also don't tell you is that the center lock systems don't employ a universal lock nut pattern. Ergo, not every tyre shop will have the necessary equipment to unlock your wheel shoud anything untoward happen and you need an emergency tyre change. That's not really ideal for road cars now, is it?

In contrast, you'd have no such problems with cars that have multiple wheel locks, as most tyre shops have the necessary tools to work on them. Even if you lose a lug nut or two, they don't cost the GDP of a small country to replace.

Things can go south rather quickly

While the idea of a single, center wheel lock nut is aesthetically appealing, this system requires added care and precision when installing. Imagine now, if it's incorrectly installed or not tight enough, your wheel will come off.... while you're driving. Doesn't sound really pleasant, does it?

To give you a glimpse of just how precise the installation of center lock nuts need to be, let's use Formula One again as an example. Some of the most skilled technicians and pit crews work here, yet even they can get the installation of the center wheel lock wrong. Just look at the video below.

Let's face it, your regular tyre guy won't be as skilled and precise like a Formula One pit crew, and he/she has to deal with a higher volume of cars. Mistakes are bound to be made. At least, with multiple wheel locks, if one fails, there are at least 3 more serving as backup to hold the wheel in place.

With a single wheel lock, you only have a single pint of failure, as opposed to a 4/5-lock set up. This is one major consideration why road cars generally don't employ a single wheel lock system. Did I already mention that they're not cheap?

Conclusion

So there you have it, reasons why manufacturers of road cars gravitate to using multiple wheel locks instead of a single one. Obviously when manufacturing race cars, the ultimate aim is speed, weight reduction and winning. 

This is in contrast to road cars that need to factor in cost, durability and serviceability for the duration of its lifespan. Still, if you're feeling fancy, you can always dress up your multi wheel lock configuration with some snazzy lug nuts, if you so desire.