Why do German cars use lug BOLTS instead of lug NUTS?

September 4, 2005 8:35 PM

Why do most European cars use lug BOLTS to secure a wheel to a car as opposed to lug NUTS as in most American and Japanese cars? Is there an advantage or disadvantage? I have a VW and recently had a heck of a time getting bolts to fit my aftermarket wheels...it seems that you can get all the nuts you want though in PepBoys... THANKS!

Going nuts over lug bolts... !

posted by skyguy14 to travel & transportation (13 comments total)

My Volvo uses lug nuts. So other than VW, which makers use bolts instead of nuts?
posted by goatdog at 9:18 PM on September 4, 2005

I don't know why they'd use bolts instead of nuts. Can't think of a real advantage to it.

As to where you can get them... is there anything special about them? There are lots of nuts-and-bolts providers, both online and brick-and-mortar, that will have pretty much every size and thread you can imagine. Bolt Depot is pretty good, I've bought a lot of stuff from them.

Also, check out this froogle search
posted by RustyBrooks at 9:18 PM on September 4, 2005

Oh, and please don't take my Bolt Depot recommendation tooo seriously. I know jack all about cars, so for all I know, there are some special qualities the lug bolts have. Replacing them with something unsuited could be real bad I guess.
posted by RustyBrooks at 9:21 PM on September 4, 2005

No, Bolt Depot is for hardware - thanks though... car wheel lug bolts are like this: http://www.prestigewheel.com/mainBolts.htm. And goatdog, your Volvo, my VW, Audi, Porsche, and Mercedes all use bolts... ;-)
posted by skyguy14 at 10:06 PM on September 4, 2005

My guess is that there's probably more threaded surface area of contact on a lug bolt, reducing the chances of the bolt coming loose. Aesthetically, it might make for a tidier looking wheel.

But just from personal experience, I find that lug bolts don't run away from you as easily as lug nuts when changing a wheel, and they're easier to pick up if you're wearing heavy work gloves. (I have delicate hands!).
posted by Extopalopaketle at 1:06 AM on September 5, 2005

Also remember that car-wheel bolts are threaded in the opposite direction standard bolts so that the rotation of the wheel tightens them rather than loosens them, so a hardware bolt, even if it fitted, wouldn't work...

Certainly, my old Mercedes and my current Peugeot both use bolts, and I can't recall changing a wheel on a European car that didn't. I'm not sure why there would be a geographical difference - could it be a manufacturers difference? Do Ford cars in Europe use nuts, for instance, or would a Merc in the US use bolts maybe? (I can't imagine a major manufacturer producing two different wheel hubs just because Americans prefer nuts or European prefer bolts...)
posted by benzo8 at 2:43 AM on September 5, 2005

Also remember that car-wheel bolts are threaded in the opposite direction standard bolts
This is far from universal, and if it were for the reason given, the bolts on one side would still have a right-hand thread. (Which they may; I only had one car that used bolts.) Some older American cars (Chrysler?) did have left-hand lug nuts on one side of the car, and right-hand ones on the other.

Stud-and-nut systems are much easier to load a heavy wheel onto than bolt systems. Either system is easy if you adjust the car height to match the wheel.

Wheel-fastening hardware of either type is very high-strength steel (grade 8 or 9). You might find regular hardware that would fit, but using it would compromise safety.
posted by Kirth Gerson at 3:43 AM on September 5, 2005

Kirth Gerson writes "Also remember that car-wheel bolts are threaded in the opposite direction standard bolts
"This is far from universal"

Ah, OK - my limited experience of changing wheels shown up for what it is!

Kirth Gerson writes "Stud-and-nut systems are much easier to load a heavy wheel onto than bolt systems. Either system is easy if you adjust the car height to match the wheel."

I was thinking this might be a reason, and why it could be geographical, but I refrained from saying it because I know all the USAians would jump up and down on me. But, is it a possibility that consumer-pressure in a country dedicated to making things as easy as possible for themselves has led manufacturers to implement the easier system in the US? And if so, why haven't the Europeans followed suit, if only because it makes sense to manufacturer one wheel hub per type of car in a global market - is the bolt system more secure, perhaps?

Man, I'm asking more questions in this thread than skyguy14, but it's really piqued my interest - good question!
posted by benzo8 at 4:01 AM on September 5, 2005

My Mercedes has bolts threaded backwards only on one side and correctly on the other. I didn't even realise some cars used nuts instead. That sounds like real hard work to me.
posted by wackybrit at 4:28 AM on September 5, 2005

I've driven a lot of European cars (including Volvos, Land Rovers and VWs), and the only one I've seen with bolts is a very small Citroën that used three bolts per wheel. And this I discovered at 00:45 on January 1st, 2000 when a pothole in a really rough part of Glasgow took out a front tyre, and my torch had about two seconds of battery life in it.

I don't like wheelbolts very much ...
posted by scruss at 6:50 AM on September 5, 2005

I had an old '84 BMW that used wheel bolts. I always thought that was sort of cool. Definitely a PITA to change wheels, though. And, yes, the threads were different between the two sides of the car.
The hood hinged forward, too. Added to that "foreign-ness".
posted by Thorzdad at 7:49 AM on September 5, 2005

How do you get the wheel in place with lug bolts? With the lug nuts, you place the wheel onto the bolt part which is built into the car. Is there something there to hold the wheel on while you put the new tire on?

Bolt Depot does carry grade 8 steel bolts. I don't see any reverse threaded ones though. I see now that the bolts are shaped a little differently than normal bolts.

This seems like a good argument to use lug nuts instead of bolts, to me. It's a lot easier to find replacement nuts than bolts.
posted by RustyBrooks at 9:46 AM on September 5, 2005

All the VWs and BMWs I have seen (late model, in my family at least) have the axel protruding a bit so you can lift the wheel up on to it - the wheel will stay there by itself, then you thread the bolts in to mearly hold the wheel on. It is not an issue to mount the wheel as the bolts do not support it. Depending on the amount of load carried by that protrusion, it reduces the load on the wheel bolts and transfers the weight born by the wheel using normal studs to the axel. This takes the weight and sheering force of the car off the direct side of the bolt where it is weakest and the bolt, and it is only required to be stressed lengthwise where it is most strong (to hold the wheel on with tension). This is my best guess after we explored all other avenues (thanks for all the info). There is related info here (look at the second question regarding "Lug Centric"). PS: All of my wheel bolts are normal RH turning on my 04 VW.
posted by skyguy14 at 10:36 AM on September 5, 2005