ET on wheels and wheel bolts

[retromadness123]

Hello guys needs some help and I do apologise if this has been asked before but wanted to know about what is ET on wheels and what the numbers mean next to it for example what is ET30, also I recently requires a set of Mercedes amg monoblocks replicas and the front wheel has a smaller ET to the rears now I need to buy some wheel bolts and was wondering would both the front and rear wheels both need the same wheel bolts regardless off the different ET sizes thanks for all the help in advance thanks

[Rich]

Right, so, this would have been better to throw at google as I’m sure there are a millionty articles detailing it. But.
ET is the offset of the mounting face of the wheel from the theoretical centreline of the wheel in MM. this won’t affect the wheel nuts or bolts you require. A different offset figure front and rear creates a staggered wheel fitment effect, common on Mercedes and BMW.

[ChasR]

May 9, 2019 20:34:28 GMT retromadness123 said:

Hello guys needs some help and I do apologise if this has been asked before but wanted to know about what is ET on wheels and what the numbers mean next to it for example what is ET30, also I recently requires a set of Mercedes amg monoblocks replicas and the front wheel has a smaller ET to the rears now I need to buy some wheel bolts and was wondering would both the front and rear wheels both need the same wheel bolts regardless off the different ET sizes thanks for all the help in advance thanks

As said, it's on Google alot!

After reading your reply a few times I'll try and advise.

ET refers to the difference of the centreline of the wheel to the face that mounts onto the hub. That's the offset. If it's ET30 for example, the face that mounts onto the hub is 30mm towards the kerbside of the wheel away from the centreline. Hopefully that makes sense. Of course, ET-10 is a wheel where the mounting face of the wheel is 10mm towards the hub from the centreline of the wheel. ET0 of course refers to the mounting hub face of the wheel being smack bang in the centreline of the wheel.

Of course, if you go wider on wheel, that will affect the offset. Stick with the same ET, your wheel will go closer by the same distance each side to both the arch and the strut/inner arch of the car. That's where more thought is required.

Your front Merc Monoblocks probably have a smaller ET number up front to clear the struts up front.

As for the wheel bolts, ET makes no difference. Go to a tyre shop and get them to tell you what bolts you need. As an example, I've owned 3 Mercs (including my current). Here were the wheel bolt combos
-First W124 250D were on steels. They took Radius bolts
-My S124 E320 was on 7J Sportlines. They also took a similar Radius bolt, but suited for alloy wheels
-This one gets interesting. My W108 came on Steels, with Radius bolts. Like yourself, I bought some Mexican Hat 15" Replicas. Most here will know that Mercedes didn't make a 15" Mexican hat wheel. Mine are ATS wheels. Despite being a Mercedes designed wheel, they took taper seat bolts, like most normal cars out there.

[retromadness123]

May 9, 2019 22:47:32 GMT ChasR said:

May 9, 2019 20:34:28 GMT retromadness123 said:

Hello guys needs some help and I do apologise if this has been asked before but wanted to know about what is ET on wheels and what the numbers mean next to it for example what is ET30, also I recently requires a set of Mercedes amg monoblocks replicas and the front wheel has a smaller ET to the rears now I need to buy some wheel bolts and was wondering would both the front and rear wheels both need the same wheel bolts regardless off the different ET sizes thanks for all the help in advance thanks

As said, it's on Google alot!

After reading your reply a few times I'll try and advise.

ET refers to the difference of the centreline of the wheel to the face that mounts onto the hub. That's the offset. If it's ET30 for example, the face that mounts onto the hub is 30mm towards the kerbside of the wheel away from the centreline. Hopefully that makes sense. Of course, ET-10 is a wheel where the mounting face of the wheel is 10mm towards the hub from the centreline of the wheel. ET0 of course refers to the mounting hub face of the wheel being smack bang in the centreline of the wheel.

Of course, if you go wider on wheel, that will affect the offset. Stick with the same ET, your wheel will go closer by the same distance each side to both the arch and the strut/inner arch of the car. That's where more thought is required.

Your front Merc Monoblocks probably have a smaller ET number up front to clear the struts up front.

As for the wheel bolts, ET makes no difference. Go to a tyre shop and get them to tell you what bolts you need. As an example, I've owned 3 Mercs (including my current). Here were the wheel bolt combos
-First W124 250D were on steels. They took Radius bolts
-My S124 E320 was on 7J Sportlines. They also took a similar Radius bolt, but suited for alloy wheels
-This one gets interesting. My W108 came on Steels, with Radius bolts. Like yourself, I bought some Mexican Hat 15" Replicas. Most here will know that Mercedes didn't make a 15" Mexican hat wheel. Mine are ATS wheels. Despite being a Mercedes designed wheel, they took taper seat bolts, like most normal cars out there.

Thanks, is there anyways to see if a wheel takes a radius or a conical style bolt,

[ChasR]

On something so critical I'd get a tyre shop to tell you what you need and a half decent one.

If you have a radius wheel and a taper wheel next to each other, the difference will be obvious. The radius wheels have a definite curve on the bolt seating face that can be felt.

Also, check your wheel bolt length. That caught me out on the W108 ; my longer bolts were catching the handbrake mechanism, so I had to buy shorter bolts to work with it. I think it's said that 8 threads of engagement is necessary to be safe on a wheel, but don't quote me on that.