Whydo some cars have 4 bolts holding the round bits on and some have 5?
Is it connected to the design of a wheel or the possible loading forces when cornering?
Walking into town at lunch time I happened to spot a Polo on an 08 plate that had steel wheels with 5 bolts. Surely a small car like a Polo doesn't need 5?
Curious to know what decides it.
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Small cars don't actually need 5 bolts (the 2CV had 3) but as in the case of rear disk brakes on these cars, fashion comes into play.
People in the UK seem to like aluminium wheels. This is nowhere near as good a material for the job as is sheet steel and requires more fixings to keep stress levels adequately low. As the wheel fixings are univerally visible with aluminium wheels, the 5 bolts meet their "fashion" specification and hold the rather weak wheels to the nice strong hubs with less chance of the bolts breaking out.
The steel wheel variant will of course have 5 bolts to fit the standard hub - my car is like this (but it's not small).
659.
Edited by 659FBE on 12/11/2008 at 14:28
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My VW Bora has five bolts per wheel - the first time I can recall owning a car with more than four.
So far I've fortunately never suffered a puncture requiring personal by the roadside attention....
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Is it just down to alloys or is it also to do with cars being heavier these days so the forces on the bolts are potentially greater? I've had an MG Metro, Mk2 Cavalier, Audi 80, Mk3 Golf, Pug 405, and Saab 9000 all with alloys but only 4 bolt wheels.
I saw a pic of a Cadillac CTS-V the other day and it has SIX wheel bolts - as seen on some 4x4s where many make do with 5 bolts.
I always thought 3 bolts on various French cars (did 3 bolts die out with the AX?) looked plain wrong. As a child I used to imagine their wheels falling off. ;o)
When I had my early Audi 80 quattro, I once tried to fit a spare wheel from a lesser 80 on to it but it wouldnt fit - I found out that 2WD 80s used M12 wheel bolts but my quattro had M14 bolts.
I failed to see the point of this lack of parts sharing - running gear was mostly the same as the urQuattro but those hubs were different again, urQuattro had 5 bolts.
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I don't think it's as simple as that 659.
Myself and SWMBO both had Astra Elegances at one time. One was a 1.6, the other a 2.0 diesel. Both had the exact same 16" alloy wheel design, in the same size etc.
However, the petrol had 4 bolts per wheel and the diesel had 5 bolts!
The only difference between the two cars (apart from engine) was that the petrol had rear drums whereas the diesel had rear discs.
It was simply the case that the disc hub had 5 bolts as standard, so the wheel needed to be modified to accomodate it.
Whether or not that was to allow for larger alloys on other (more powerful) models, I don't know.
I have seen some 4x4s with 6 bolts per wheel!
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Granada/Scorpio went from five to four whilst Mondeo went from four to five.
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I remember being told that when refitting a wheel that it was advisable to tighten the wheel nuts / bolts in a particular sequence. Tighten one then the one diagonally opposite and so on. This is quite difficult to do when there are 5. I have not let it worry me though.....
:-)
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particular sequence. Tighten one then the one diagonally opposite and so on. This is quite difficult to do when there are 5.
I tighten them in the order that you would draw a 5-pointed star..
;o)
Edited by Rich 9-3 on 12/11/2008 at 15:51
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That's one of the advantages of the wisdom of age. You begin to accept that you can't know everything.......and that there are a few people who might even be slightly more intelligent than oneself.......Very good, I'll remember that in future.
;-)
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I can't claim that as my own, I thought I might have read it somewhere... Sure enough, just looked in my cars handbook there is a diagram entitled, "Tightening sequence, wheel studs."
:o)
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That is genuinely comforting Rich ! However, it is now in the domain of snug ammo for use when it goes quiet in the Fox and Rabbit of a winter's night.....
:-)
Edited by Humph Backbridge on 12/11/2008 at 16:21
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>I always thought 3 bolts on various French cars (did 3 bolts die out with the AX?) looked plain wrong. As a child I used to imagine their wheels falling off.
My parents drove various Renaults for a combined total of 36 car-years in the 60s, 70s and 80s. All had three-bolt steel wheels; one of them (a 12 estate) seemed to suffer a surprising number of punctures but I don't remember a wheel ever falling off.
}:---)
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I know some Hondas (Hondae?) imports carried a four bolt hub whereas a very similar (though not entirely) UK model has five (Prelude, I believe).
This made me wonder how the counter-threaded spin off central nut would fair these days. Wasn't that how wire wheels were retained on some cars?
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Don't know about this performance or stresses thing - F1 cars do with one, as do even high powered motrocycles.
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My (Japan) import Prelude had 5 bolts per wheel, but strangely the horrible Orange space-saver spare only had four, and these were dedicated to the spare, as they were shorter than the ones that held the alloys on! - wierd!
Billy
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Various Saxos and 106's could still be had with 3 wheel bolts per wheel throughout their livespans.
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You're absolutely right - I suspect the 3 bolt version was a hangover from the Citroen AX on which the 106 was based.
I wonder if PSA ever did what BL once did to a Marina (disk brake on one side front, drum on the other) and got the hubs mixed up?
659.
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Various Saxos and 106's could still be had with 3 wheel bolts per wheel throughout their livespans.
What always bothers me about cars with only 3 wheel bolts is what if you lose one changing a flat in the middle of nowhere? 3 bolts on a 4 stud wheel, not ideal but get you home/to the garage, but a wheel only held on by 2 bolts that are over on one side of the wheel sounds very dangerous IMO.
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i believe tatas car for the people is a 3 bolter, keeps the price down.
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It has been said that the number of wheel bolts is indicative of the quality of the car....the more the better.
My Renault F6C Fourgonnette has 3, my Jowett 8HP had 6.
Ted
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I think a wheel nut counter is the car equivalent of a train spotter!
;-)
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No! - ones a "Nutter" - the others are "Anoraks""
::makes a (wheel) bolt for it::
Billy
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My Armstrong-Siddeley had six but they were small.
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PCD must come into it as well.
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