Boeing will begin the final phase of wind tunnel testing on the 737 MAX next week, the company announced in Singapore Monday.

Testing will take place at QinteQ’s Farnborough, UK, facility and Boeing’s transonic wind tunnel in Seattle. “We will then be able to look at firming up the configuration of the aircraft,” Boeing Commercial Airplanes marketing VP Randy Tinseth said.

The first MAX flight is scheduled for 2016 and first delivery for 2017.

Tinseth said the smaller fan of the MAX’s CFM International LEAP engine and the lighter weight of the aircraft versus its rival, the Airbus A320 neo, will give it a 6% fuel consumption advantage on a per flight basis based on a 500 nautical mile flight.