They've got monster trucks running these carbon-fiber Driveshafts now, My old room-mates Chevy 1500 had a carbon-fiber one in it too (rear, steel up front). Withstood enough force while we were wheeling to split his front differential in half. I thought he jumped it and landed on a rock at first, but apparently it just snapped the housing in a way I'd never even heard of, he did have a good set of 35's though and that V8 ran pretty strong.
But yeah, aluminum is quite strong when it's applied correctly.
*edit to jay jigless:
well Aluminum isn't necessarily soft, it can be quite hard. Where aluminum excels is it's strength to weight ratio, to obtain the same strength as a steel part, it does need to be a bit bigger, but it will still weigh less. There's processes like Anodizing than can also harden aluminum, like a case harden, sometimes just as strong as steel or even stronger. They use it for as bushing material actually, and often the steel part wears out first
Aluminum also has a higher rate of fatiguing compared to steel, but if that's taken into design consideration, again, it's almost a moot point.
Since my Ranger is staying 4cylinder, I somehow doubt it will influence my towing limit lol. But in all seriousness, things like brakes, tires, suspension, load distribution, and good ol' fashioned patience are far,
far above engine performance when towing. You can take a while to get it moving, the same can't always be said for stopping or having to pull some sort of emergency maneuver because bad drivers are attracted to those who tow.
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