Yes bluetooth and WiFI do consume power but only a small fraction of the power consumed by the GPS, the screen, and searching for the next cell when driving cross country. The only times I turn bluetooth and WiFi off are when required by the FAA, and when I want to recharge the battery as quickly as possible. Assuming iOS 8 look in Settings > General > Usage > Battery Usage and you will find a log of what percentage of battery power has been used by each app in the last 24 hours or the last 7 days. Unfortunately this does not break down the power usage by system hardware function, but it will give you an idea. There is an app called Battery Power Free that shows the time various services are in use, but it does not show the %power consumption for each service.
