He feels a close bond with his musicians and tells me he is "determined that every concert gets given their full 200 per cent".
There is no rivalry with London as, frankly, life is better up north.
"I don't know how musicians survive in London," Petrenko says. "It is hectic. They work extremely hard for not so much reward. Life is less expensive in the smaller cities and the provincial orchestras even have slightly more time for rehearsal."
The RLPO's fame has spread around the globe, thanks to its series of Shostakovich recordings on Naxos.
"It's important doing the whole cycle of symphonies so you can fully explore the composer's personality," says Petrenko. "I feel that all the sets that have been done before either exaggerate or underestimate the political significance of these works. If nothing else, they are certainly autobiographical, giving us a history of himself, his country and his people."
All 15 symphonies have now been recorded with two CDs awaiting release and Petrenko admits his big discovery was No 12.
"This was commissioned by the Communist Party for its anniversary and it's one of Shostakovich's most cryptic scores. It's extremely anti-Lenin and very, very good music."
Tonight's Leningrad Symphony packs a similar punch.
"We soon realise that the anti-humanistic forces of the first music will not have a victory," Petrenko declares. "The human spirit will win out. It's a very important and powerful message."
Bartok mercilessly lampooned the symphony in his Concerto for Orchestra but American poet Carl Sandburg described it as "music written with heart's blood". For Leonard Bernstein, this and Shostakovich's Symphony No 5 were the last noble strains in a world the American felt had surrendered to the cool, hip, put-on and campy.
"There were historical reasons for its importance, too," Petrenko adds. "The symphony was premiered in wartime and eventually broadcast across the nation from the besieged city of Leningrad, becoming a symbol for victory in the Second World War."
Listening to his advocacy of a symphony that spoke for the people of its time, one understands why he is so committed to composers of today.
"If we don't do contemporary music, then music will stop," he warns. "And we don't want it to stop. If our composers' music lies on a shelf, unperformed, no one will know about it. And music will not develop."
Performance
What: Leningrad Symphony - New Zealand Symphony Orchestra
Where and when: Auckland Town Hall, tonight at 8pm