Southwest says it will have the USA's widest 737 seats

Passengers will soon be getting wider seats on Southwest Airlines.

The seats won't begin flying on Southwest's planes until 2016, but – once they do – customers on those planes will get close to an inch of extra width.

Southwest claims that the 17.8-inch width will give it the widest 737 seat of any U.S. airline, Bloomberg News reports. Southwest, which flies only 737 aircraft, operates the world's biggest fleet of 737s.

Bloomberg notes Southwest's new seat "compares with 17.1 inches on Southwest now, 17 on Alaska Airlines and as much as 17.3 on some United Airlines 737s in economy class, according to the SeatGuru.com website."

"The new aircraft seats are the widest economy seats available in the single-aisle 737 market, and offer a unique design that gives our customers what they asked for: more space," Southwest's Chief Commercial Officer Bob Jordan says in a statement.

Southwest will be the first carrier to put the seat on its planes, starting with new Boeing 737-800 jets that will begin arriving next year.

"Serving as the launch customer for this seat is just one of several upcoming milestones related to our bold, new look launched in September of last year, and is specifically aimed at enhancing our customer experience," Jordan adds.

The carrier also will add the seats to its new Boeing 737 MAX jets, which are due to begin arriving in 2017. Southwest will be the launch customer for that variant of the 737.

One thing that won't change is seat "pitch," or the measure of the distance from the back of one seat to the back of the next. That will remain at about 32 inches, Bloomberg says.

The airline unveiled the seat for its all-737 fleet on Tuesday at the Aircraft Interior Expo in Hamburg, Germany. Southwest says it partnered with B/E Aerospace to design the seat.

The move, of course, comes at a time when fliers are seeing most other spaces inside aircraft cabins getting tighter.

But while customers will be happy with wider seats, there's an advantage for Southwest too. They will be lighter than previous ones, shaving off about 200 pounds in weight, according to Bloomberg. That will reduce fuel consumption on planes with the seats.

"The new, lighter seat allows us to continue to improve our fuel efficiency," adds Mike Van de Ven, Southwest's Chief Operating Officer. "This seat selection is just one more reason we are enthusiastic about our fleet modernization plans."