Mercedes boss Toto Wolff says he cannot deny reliability issues cost Lewis Hamilton the title this year, but says that should not undermine Nico Rosberg's championship success.

Rosberg beat Hamilton to the 2016 title by five points after securing a second place finish behind his teammate at the season finale in Abu Dhabi on Sunday.

In a year when Mercedes suffered remarkably few reliability problems across both cars, two MGU-H issues during qualifying for the Chinese and Russian Grands Prix and a dramatic engine failure while leading the Malaysian Grand Prix proved costly for Hamilton. The MGU-H problems also resulted in a grid penalty at the Belgian Grand Prix when Mercedes strategically stocked up on power unit components in the knowledge he would exceed his quota before the end of the year.

In contrast, Rosberg suffered relatively few reliability issues over the season and only one had a direct impact on a race result when a gearbox glitch resulted in a penalty at Silverstone.

For Hamilton, the reasons why he lost the 2016 championship are clear.

"I did everything that I could, particularly towards the end [of the year] and obviously Nico had a very, very clean year without any real issues to be honest and that's why we sit in this position right now," he said. "But he did a fantastic job, so big congratulations to him, it's a great feeling to win the world championship and I look forward to fighting with him next year."

The Malaysia failure is often recognised as the turning point in the season. Hamilton had a comfortable lead in the race when the big-end bearing failed and Rosberg was on a recovery drive following contact at the start of the race. Overall, the failure resulted in a 28-point swing in Rosberg's favour, which would have had a significant impact on how the two drivers approached the final races of the season.

"I think you need to win and lose with dignity," Wolff said when asked how he would react to those claiming Rosberg won the title through luck. "This is a mechanical sport and if they would sit on the floor on the starting grid they wouldn't go far. This team has built them the best car over the last three years, has made them win races and championships and this team has also let them down on occasion -- but on less occasions than making them celebrate.

"This year, clearly, Malaysia cost Lewis the championship. It's clear. But on the other side we have spent the last ten minutes discussing Lewis and the situation without recognising Nico's achievement racing against the most talented driver and teammate and winning a world championship, and making it close the years before.

"It's quite an achievement and I think we should honour it because he's tough cookie and he doesn't let go. There are some quite remarkable character traits about him that make him a champion and a worthy world champion."