"I was very lucky to be teamed up with Timo and Mark last year and while it was all new for us we were a very tight unit by the end of the season," said Hartley from England.
"It feels like a real family now and I think it is important to keep it together, [so] I'm excited to be racing again with Timo and Mark.
"We all want the same and are looking forward to building on what we learned and achieved last year."
For most drivers who have already gone through an entire season with a radical and newly designed and created race car, you'd think the prospect of doing it all again a second year might be a bit daunting.
Not so for Hartley who is very impressed with the gen2 car and keen to see just how the new 919 stands up against the Audis, Toyotas and others.
"I've lived close to Silverstone for a long time and raced there many times in Formula Three, 2-litre Renault, sports cars and others. It's a track I love to race on. It's real driver's circuit.
"It's full of high-speed corners where you get to feel these cars at speed and on the limit. It seems a long time since we were last racing and while the Prologue was good, you still don't really know what the other teams are doing around fuel load, strategy and tyre usage.
"I guess a lot of the questions are going to be answered this weekend. Some things will be track-specific where a team might show a lot of pace at Silverstone, but might not be so good during the rest of the season.
"It'll [Silverstone] be a good indicator, as the winner here in recent years has gone on to win the championship.
"You always want to put the marker down in the first race and there's a lot of excitement in the build-up to this race and everyone's going to be giving it their all."
For fans of both sports car racing, and the Kiwis in particular, the race will be streamed live, and there is a downloadable app from the WEC website that allows you to ride on board with Hartley, or any driver for that matter.
2015 WEC calendar
April 12: 6 Hours Silverstone
May 2: 6 Hours Spa-Francorchamps
June 13-14: 24 Hours of Le Mans
August 30: 6 Hours Nurburgring
September 19: 6 Hours Circuit of The Americas
October 11: 6 Hours Fuji Speedway
November 1: 6 Hours Shanghai
November 21: 6 Hours Bahrain