Weight of magnesium/alu oil pan vs. steel replacement?

[JoeFromPA]

Hi all,

I can't find this information anywhere - early f8x models had a magnesium-aluminum oil pan to save weight. BMW then switched to a steel model. Does anyone know the weight difference?

I was thinking about this this morning because the new Audi RS3 is claiming 40 pounds weight reduction by using a magnesium oil pan. (http://www.autoblog.com/2017/03/21/2...-review-tile-4)

Joe

[CanAutM3]

40lb savings for an oil pan The oil pan itself more than likely weighs way less than this, it must be a typo in the article...

Digging in RealOEM.com, I found that the discontinued oil pan is listed at 3.060kg while the new one is at 4.450kg.

So I deduce about 3lb of weight was gained when moving away from the Mg oil pan.

[JoeFromPA]

Maybe they mean the entire crankcase? IDK.

[jzmundy]

Originally Posted by JoeFromPA

Maybe they mean the entire crankcase? IDK.

Something probably lost in translation along the chain of communication. I can't imagine an oil pan for an I-5 weighing more than 40lbs to begin with, unless it was made of lead.

[JoeFromPA]

Originally Posted by jzmundy

Something probably lost in translation along the chain of communication. I can't imagine an oil pan for an I-5 weighing more than 40lbs to begin with, unless it was made of lead.

Yeah, it seemed a little off to me but who knows. Your average iron rotor weighs ~13 pounds a piece (bigger, thicker rotors can run 17+ pounds) so I know there's alot of weight to be saved when moving to magnesium-aluminum when it comes to thick iron-based parts. But yeah, 40 pounds did seem a little crazy.

My main question though was just what it was - about the f8x platform. They originally turned out magnesium-alloy oil pans, which are awesome, then went back to steel which I'm guessing is both cheaper and more standard to make/handle ( I think this is cost-cutting, plain and simple). Was curious about the weight difference.

[CanAutM3]

Originally Posted by JoeFromPA

My main question though was just what it was - about the f8x platform. They originally turned out magnesium-alloy oil pans, which are awesome, then went back to steel which I'm guessing is both cheaper and more standard to make/handle ( I think this is cost-cutting, plain and simple). Was curious about the weight difference.

post #2...

[hotrod2448]

Originally Posted by JoeFromPA

Yeah, it seemed a little off to me but who knows. Your average iron rotor weighs ~13 pounds a piece (bigger, thicker rotors can run 17+ pounds) so I know there's alot of weight to be saved when moving to magnesium-aluminum when it comes to thick iron-based parts. But yeah, 40 pounds did seem a little crazy.

My main question though was just what it was - about the f8x platform. They originally turned out magnesium-alloy oil pans, which are awesome, then went back to steel which I'm guessing is both cheaper and more standard to make/handle ( I think this is cost-cutting, plain and simple). Was curious about the weight difference.

I'm sure they would try to dodge the cost saving argument by making a BS argument about lowering the center of gravity by increasing the pan weight.

[teefive]

Originally Posted by JoeFromPA

Yeah, it seemed a little off to me but who knows. Your average iron rotor weighs ~13 pounds a piece (bigger, thicker rotors can run 17+ pounds) so I know there's alot of weight to be saved when moving to magnesium-aluminum when it comes to thick iron-based parts. But yeah, 40 pounds did seem a little crazy.

My main question though was just what it was - about the f8x platform. They originally turned out magnesium-alloy oil pans, which are awesome, then went back to steel which I'm guessing is both cheaper and more standard to make/handle ( I think this is cost-cutting, plain and simple). Was curious about the weight difference.

If I remember correctly, corrosion (of the magnesium pan) also had something to do with the switch. Basically, the increased cost + corrosion + barely any weight savings (esp with a low COG) didn't end up making a ton of sense.

Maybe the next one will have a plastic composite pan (like a lot of VWs, 991.2s, etc.)

[Fast4d]

corrosion? inside or out?

I have (had) quite a few motorcycles with magnesium valve covers and other engine parts. never had any such issue.

[teefive]

Originally Posted by Fast4d

corrosion? inside or out?

I have (had) quite a few motorcycles with magnesium valve covers and other engine parts. never had any such issue.

Outside. Some reading material on the subject: http://www.thefabricator.com/article...from-corrosion