Weight: Why is MB only 0.4 pounds lighter than MBP?

[CommodityFetish]

MB 13": 5.0 pounds
MBP 15": 5.4 pounds
MBP 17": 6.8 pounds

Why is the MB so heavy compared to the larger MBP? Plastic vs Aluminum case? When the MB goes aluminum, will it get lighter?

12" Powerbook was 4.6 pounds...

How much does an optical drive weigh?

Just curious...

 

[butterfly0fdoom]

The polycarbonate for the MB's casing is rather heavy.

 

[CommodityFetish]

Ah, makes sense. So I guess they should get lighter when/if they go aluminum... That's good news.

 

[Cloudsurfer]

Aluminum would make the MacBook lighter, but not by much. I think they would be just under two kg when they go aluminum.

I think the battery is the heaviest part of the machine. A battery-less MBP actually weighs less than a MacBook with battery.