As of OCT 2016. I have a contact who works at the border in immigrations in Tacna. He told me the law has always been 6 months per year max. However, the software system they use allows the border agent to enter up to 183 days, and no more. BUT it does not limit him, so it is the border agents' decision how long you will get. He also told me that because of the new PPK administration, a bunch of new folks are now working the borders who make alot more money, and are NOT willing to bend the rules. He says it is very difficult to get more than 60 days.
He says the only difference between Peru and Ecuador is that in Ecuador the computer automatically calculates your maximum visa stay based on how long you have been there in the last year. So the Ecuador border agents cannot put a figure greater than the computer allows - Peru agents can. There are some reasons to ask for 180 days, but you have to prove a valid reason, like getting married, having a kid, or some legal commitment, but you have to prove it. Send me a private message and I might be able to get more answers for your situation.
..A Peruvian once asked me:what's the difference between special and abnormal?.....well my answer was : Lady Gaga and Miley Cyrus..