If I were to, say, make a tube buggy, out of aluminum, would the weight savings be worth it?  Or how about stainless steel, never worry about rust again?

You must be rolling in the green! Or smokin it....

I could not even imagine the amount of $$$ needed for a project like either of those 2!! Regular DOM tubing is getting outragious. Aluminum is ungodly as is SS. I would think Aluminum would just break, where as steel would bend, so AL may not be the best idea. Just make sure you plish the SS. 

Chief is right when it comes to the $$$$$

     Aluminum is ungodly expensive. In my aircraft projects it's what we use for almost everything...example
- 2" by2' by 1.5' plate....6061-t6
- 12" of 10" round bar...6061-t6
- 8" of 6" round bar.......6061-t6

With paperwork to insure grade and quality    1240.00 CDN

And that was just for the redrive...

Strength is not a problem provided you use the correct alloy and it's correctly assembled.

Weight savings, about 1/3...roughly

Cost...outrageous

Zag

tubular ai??? that sounds like fun.  me an my friend are currently turning a 1 ltr Santana into an autocross car.  weve got some pretty good tyres for the back, colway MTs, similar to BF goody's so ive heard.. and some extreme snow/extreme sand front tyres.. this should make for some good side ways action in 4wd.

I think you'd be better off using regular tubing for the body, doing something to protect it like paint with POR 15, Rust Encapsulator, or Herculiner, and then use fiberglass or lexan for the few body panels necessary.

I saw something like this a while back.  Guy took a Samurai that was all crusty, stripped off the drivetrain, power train, seats, suspension and a few other goodies and built a tube frame and body and paneled it with fiberglass.  It didn't even weigh a ton when he was done with it.

1240cdn whats that like 20 bucks american

Hey Suzuki 1.8

     Tell your boss to donate some of your aluminum stock to my cause!


20.00 US...yeah right. LOL

Zag

hmmm 20 USD... whats that....    £5 GBP    HE HE

I don't think the weight savings would be worth the cost and having a weaker chassis than using DOM.

Use chromoly if you want it light

Shoot, bite the bullet and use Titanium, super light, super strong AND won't rust!

Just have your $$$$ ready.

would carbon fibre work???  that would be nice an light.... dunno if i would like to roll in it though... probably would cost a fair bit too.... just an idea

Shoot, bite the bullet and use Titanium, super light, super strong AND won't rust!

Just have your $$$$ ready.

Titanium is twice the weight of aluminium and much more difficult to work with.

fiberglass tube buggy?

Shoot, bite the bullet and use Titanium, super light, super strong AND won't rust!

Just have your $$$$ ready.

Except it's really brittle, so it probably wouldn't work out too well

I feel the need to educate.
DOM is mild steel, just seamless and heavy wall,
no special alloys or any fancy stuff.

Chromolly is the way to go for strength