Alloys and Tyres
I personally do not have alloys on my car, though if I could afford them I'd have them straight away, they look nicer, show of your shiny discs and if good quality release the unsprung weight of the vehicle. My main job was the manager of a performance centre, so i know a little about what i'm talking about, so hopefully all your questions will be answered on this page.
Though like always get in touch if you believe i'm wrong or have any other questions.
Though like always get in touch if you believe i'm wrong or have any other questions.
OE or After Market, whats the difference?
Their are two main differences between OE and aftermarket alloys, the first is that the OE alloys have be painstakingly chosen to match the design of the vehicle, the second is that OE alloys are direct fit.
What is Direct Fit?
OK direct fit means that the wheels fit diectly on the vehicle with no modifications what so ever.
For instance old Vauxhalls (let's say 1998 Corsa) have a 4 stud wheel pattern and the distance between one stud to the other using the longest measurement from the cetre of the hole to the other centre (see pic) is 100mm. We call this the PCD (Pitch Circumfernece Diameter). Now one Vauxhall with a PCD of 100mm will most probably fit another with the same PCD however.....
A lot of other manufacturers use this PCD including VW, Toyota, Nissan etc.
Now you have the hub fitment to worry about, whats that then? All manufacturers wheel hubs are different sizes, Vauxhalls 4 stud hub measures 56.6mm, therefore the rear centre of the wheel needs to be machined at 56.6mm. Aftermarket alloys use something called a spigot ring, this is a ring which goes in the back of a wheel with a PCD of 100mm, the spigot ring (plastic or metal) is exclusive to that wheel manufacturer and will have an internal diameter of 56.6mm or whatever your car is. This is what makes this wheel fit your cars hub.
What is Direct Fit?
OK direct fit means that the wheels fit diectly on the vehicle with no modifications what so ever.
For instance old Vauxhalls (let's say 1998 Corsa) have a 4 stud wheel pattern and the distance between one stud to the other using the longest measurement from the cetre of the hole to the other centre (see pic) is 100mm. We call this the PCD (Pitch Circumfernece Diameter). Now one Vauxhall with a PCD of 100mm will most probably fit another with the same PCD however.....
A lot of other manufacturers use this PCD including VW, Toyota, Nissan etc.
Now you have the hub fitment to worry about, whats that then? All manufacturers wheel hubs are different sizes, Vauxhalls 4 stud hub measures 56.6mm, therefore the rear centre of the wheel needs to be machined at 56.6mm. Aftermarket alloys use something called a spigot ring, this is a ring which goes in the back of a wheel with a PCD of 100mm, the spigot ring (plastic or metal) is exclusive to that wheel manufacturer and will have an internal diameter of 56.6mm or whatever your car is. This is what makes this wheel fit your cars hub.
Measuring a PCD
Spiggot Rings
Without a spigot ring your wheel will not be flush to the hub and with every wheel turn the wheel will move on the bolts causing violent vibrations through the steering at around 60mph+ you do not want this.
ET. What is it?
Well it's not little green men, it's actually EinpressTeife. Its the amount of metal on the rear of the wheel and its measured in MM. I never said this was going to be simple! A Vauxhall has a large ET on well lets say a Corsa B again, it's actually ideally around ET42, now the higher the ET the further towards the inner arch the wheels will be, therefore clearing the outer arch (So all those cars with alloys sticking right out WRONG ET).
So Vauxhall Corsa
PCD 4x100mm
56.6 Spigot Ring
ET 42-45
Or you could just but original equipment OE
So Vauxhall Corsa
PCD 4x100mm
56.6 Spigot Ring
ET 42-45
Or you could just but original equipment OE
What tyres fir my car?
When people fit new alloys they usually want to go bigger, that's not unusual, metal looks better than rubber and it's really quite simple to calculate, for instance............
My Zafira comes from the manufacturer with 195/65/15 tyres on it, thats 15" whels OK.
So to go up I simply increase the first measurements in increments of 10, lower the second measurements in increments of 10 and increse the final one in increments of 1, example.
185/75/14 to
195/65/15 to
205/55/16 to
215/45/17 to
225/35/18 which is about the largest wheel (realisticly) you want to put on a Zafira or Astra.
The actual circumference of the wheel does not change only the width. There is though limitations on how large you can go on any vehicle.
One customer acyually put 21" wheels on a Corsa B, I obviously got him to sign a disclaimer a show car fitment but he used them anyway, it looks like a 1980's roller skate, not advised LOL.
My Zafira comes from the manufacturer with 195/65/15 tyres on it, thats 15" whels OK.
So to go up I simply increase the first measurements in increments of 10, lower the second measurements in increments of 10 and increse the final one in increments of 1, example.
185/75/14 to
195/65/15 to
205/55/16 to
215/45/17 to
225/35/18 which is about the largest wheel (realisticly) you want to put on a Zafira or Astra.
The actual circumference of the wheel does not change only the width. There is though limitations on how large you can go on any vehicle.
One customer acyually put 21" wheels on a Corsa B, I obviously got him to sign a disclaimer a show car fitment but he used them anyway, it looks like a 1980's roller skate, not advised LOL.
Do me a favour though, if you are looking for new snazzy alloys for your car, don't scrimp on price. Get a nice new set of gravity moulded quality alloys from a quality manufacturer such as
TSW http://www.tsw-wheels.co.uk/
OZ http://www.ozracing.co.uk/
Mille Miglia http://www.autowerxinc.com/wheels.htm?man_id=100
BBS http://www.bbs.com/
FOX http://www.mswuk.com/
Rimstock http://www.rimstock.co.uk/
ALCAR http://www.alcar.co.uk/4279_EN
ALCAR actually has a wheel configurator on their site where you can put alloys on you car to see what they look like, brilliant!
TSW http://www.tsw-wheels.co.uk/
OZ http://www.ozracing.co.uk/
Mille Miglia http://www.autowerxinc.com/wheels.htm?man_id=100
BBS http://www.bbs.com/
FOX http://www.mswuk.com/
Rimstock http://www.rimstock.co.uk/
ALCAR http://www.alcar.co.uk/4279_EN
ALCAR actually has a wheel configurator on their site where you can put alloys on you car to see what they look like, brilliant!