He'll also drive a factory Aston Martin Vantage V12 GT3 car at the Nurburgring 24 Hours in May and race at the Sebring 12 Hours in Florida later this month.
"It's best for me to focus on one programme because I have been doing multiple programmes for the last three years," Stanaway said during a short trip home to Tauranga.
"When you diversify like that it can take energy and focus away from each programme. So my focus is solely on WEC this year.
"I've had a year in GP2 but there wasn't any point in me doing it again unless I could have progressed in terms of team performance, which wasn't an option for me."
Not only does it propel Stanaway into fierce GT Endurance battles against Ferrari, Porsche, Corvette and the new Ford GT, it's also a sound career move.
"I've not really done a full WEC programme before. I've always compromised and missed rounds. Last year I had to miss a race to do GP2.
"Aston Martin has a race-wining car in WEC so it's better to focus on that. Long-term I think a career driving in LMP1 or DTM can be achieved from there."
Among the other benefits of a sole focus will be the amount of testing miles that Aston Martin will do as it works with new tyre partner Dunlop.
"With Dunlop on board with Aston Martin it means there is some tyre testing throughout the year," said Stanaway.
"When I got the schedule through in January and I saw the programme for this year I went off the idea of doing a dual programme just because of how busy I'm going to be.
"A cool thing about WEC is the open tyre rules. You have to work very closely with the tyre supplier to build the very best tyres possible to suit your car.
"It's not just about having the most grip but also the least degradation, which is a very opposite mentality to what you experience in GP2 or Formula 1."
Motorsport pundits are picking a very competitive year of GT racing with Aston Martin up against the new Ferrari 488 and Ford GT. But at the Le Mans 24 Hours in June the US-based Corvette and Porsche squads join the fray.
"It's going to be very tough this year with lots of fast cars and fast drivers. Le Mans is the race everyone wants to win and this year Le Mans will probably be one of the most competitive GT races of all time," said Stanaway.
"In GT racing there are great brands and the cars are very different but also very close as well. The battles go down to the wire and I'm really looking forward to it."
Early testing has been encouraging for the new Aston Martin-Dunlop partnership.
