I've got a 2014 barbarian, as the subject title suggests. Got it 18 months ago and have done >65k miles in it. About 20-25k ago the fuels economy went down markedly and so did the power. Have taken it back to the initial dealer, who were less than helpful, and to another, respected dealer, who were more helpful, but still didn't solve the issue. I can get it sorted privately though am keen to get it put right under warranty,(100k).
I'm not a mechanic though do understand some of the internal workings of modern engines.