The two McLaren-backed racers fought over the FR3.5 title all season, with the Dane coming out on top and propelling himself to an F1 race drive with McLaren for 2014.
Magnussen said that while he was not particularly focused on the comparison with another driver from the same F1 stable, he was aware that it would have been unacceptable to be beaten by the less-experienced Vandoorne.
"The McLaren link with Stoffel wasn't something I was thinking about," Magnussen told AUTOSPORT.
"But obviously with him being a rookie I had to beat him. I have to be better than a rookie, and I think I was.
"I think we have done a better job than everyone this year."
Magnussen, who partners Jenson Button at McLaren in 2014, finished seventh in his rookie season in FR3.5, and he praised the job Vandoorne did as a newcomer.
"I'm not taking anything away from Stoffel," he added.
"I think he has done a really good job and I'd like to give him my credit because he was really impressive."
The 2015 Formula Renault 3.5 season will be notable for being the last with the French company's backing but also produced a worthy champion in Oliver Rowland. PETER MILLS evaluates this year's crop of drivers
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