Control Arms: Aluminum or Steel?

[Scott C]

my aluminums were replaced by steel - cant tell the difference. Just get M5 bushings - now that is a difference.

[E34-520iSE]

I've got Alu. arms - I haven't noticed any difference at all!

Sorry,

Shaun M

[EngPhys09]

I need to replace my control arms on my car and i'm curious whether to get Aluminum Lemforder or Steel Lemforder?

Is there any obvious benefits to Aluminum? Beside the fact that its lighter? I assume this would imply that they are weaker?

The car is never going to see a track and there is about a $60 price difference between the steel and the aluminum. However the car is lowered
Anybody use aluminum or is it best to stick with steel?

Aluminum


Steel

[repenttokyo]

don't assume that aluminum is weaker than steel but i do not remember which ones i ordered, and i ordered mine a mere month ago!

[EngPhys09]

don't assume that aluminum is weaker than steel but i do not remember which ones i ordered, and i ordered mine a mere month ago!

Well obviously it depends on the aluminum that is used i just was wondering if there are any real perks

[gmannino]

Generally steel is much harder than aluminum. Ever try to cut aluminum vs steel? Big difference. Of course, there are many grades of both metals.

This is a good question, I am curious. I would lean toward aluminum for lighten the car and many motorsports use aluminum parts.

[Bimmer Nut Ed]

Aluminum arms are more expensive.

Generally speaking, the arms are the same strength. You can see that the aluminum ones are thicker, because as mentioned, aluminum is not as strong as steel. Therefore they make the arms thicker/bigger.

The main benefit is reduced unsprung weight. That's why many look for lighter wheels for their cars. In my opinion, reduced unsprung weight only helps when you are hitting bumps and potholes. Lower unsprung weight means less resistance to move, smaller impacts. I'm sure thats not the best technical explanation, but you can't say I didn't try.

[EngPhys09]

Aluminum arms are more expensive.

Generally speaking, the arms are the same strength. You can see that the aluminum ones are thicker, because as mentioned, aluminum is not as strong as steel. Therefore they make the arms thicker/bigger.

The main benefit is reduced unsprung weight. That's why many look for lighter wheels for their cars. In my opinion, reduced unsprung weight only helps when you are hitting bumps and potholes. Lower unsprung weight means less resistance to move, smaller impacts. I'm sure thats not the best technical explanation, but you can't say I didn't try.

Dont worry I'm in my 4th year of 5 for my engineering degree, i understand all this unsprung weight issues, size difference and properties of Al vs Steel.

Do you have Aluminum control arms on your car?
I dont really want all talk, I know the ideas but I just want someone who has them to tell me yes it was worth the extra cost

[Blitzkrieg Bob]

Dont worry I'm in my 4th year of 5 for my engineering degree, i understand all this unsprung weight issues, size difference and properties of Al vs Steel.

Do you have Aluminum control arms on your car?
I dont really want all talk, I know the ideas but I just want someone who has them to tell me yes it was worth the extra cost

My ///M5 and my Touring have the Aluminum arms and my 525 has steel.

I can't tell any difference between the two on the ride of the car. But the shiny silver arms are nice to look at when you're under the car.

[repenttokyo]

Generally steel is much harder than aluminum. Ever try to cut aluminum vs steel? Big difference. Of course, there are many grades of both metals.

This is a good question, I am curious. I would lean toward aluminum for lighten the car and many motorsports use aluminum parts.

how easily something can be cut isn't always an indication of its resistance to other stress.