Exhaust question....

[Mr Roper]

Why do some diesel exhaust pipes point down and some don't?





I'm guessing the answer is obvious but in all my years of driving I've never thought to ask till now..

[Mr Roper]

Is it to do with diesel engines more prone to drawing water in the event of flooding?

or

Avoids dirty great plumes of smoke being plastered over pedestrians?

or

did they realise that pointing down looks pants and changed it??

[Mr Roper]

Thanks clearing that up MT