Basically the title.
In: Engineering
Trucks drive a lot more than cars, and they’re designed to be able to work at high driving range with high weight loads without failing.
Most importantly, air brakes will stop a machine by *default*. This means if a truck’s braking system fails, the truck will slow to a stop.
Liquid brakes for a truck would and add a significant failure point that could cause accidents, plus it would require tons of liquid and much more vehicle maintenance.
So why don’t cars use air brakes if they’re so awesome? Well, they’re a lot more complex and expensive than liquid brakes. They’re also heavier — relative to the weight of a car, air brakes would really kill your fuel efficiency.
Trucks, however, have massive weight loads and get used a lot more than most cars, so the extra weight and expense is fairly trivial for them.
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