誰能幫我解釋一下下面這段話?麻煩請自己翻譯一下~不要用機器翻譯
Southwest is asking passengers to buy a second seat if their girth prevents the armrest from lowering. The airline is also flying slower - by 72 seconds, for example, on Houston to Los Angeles flights, which now take 3 hours 14 minutes. That saves 33 litres of fuel for each of the airline's four daily flights on the route, or 132 litres a day overall.