Generally speaking (ie historically and the rule of thumb), a fixed-rate mortgage will cost you more than a variable rate mortgage, over the lifetime of the mortgage. The advantage of a fixed-rate is that you know exactly what you will pay every month.
Rates are at a historical low. Does this mean they're at the bottom? The moved to a historical low the last time the rate was changed, as was the case the time before that, and the time before that again...
I know people who fixed back in 2007 and 2008, "to save money". I was on a variable paying €1,400 per month. Yesterday I paid €857.
Between this post and the previous you've both sides of the argument.