Yes using powertop, ive been able to get my last intel laptop (thinkpad t440) to ~8W and my latest amd laptop (a hp 745 g3 carrizo) to ~10W. Initial value on the intel laptop from memory was ~24W and on the amd laptop it was 21W.
This is a good start http://linrunner.de/en/tlp/docs/tlp-faq.html Depending on your HW/distro/DE, you might want to start playing around with powertop --calibrate and TLP. Highly suggest switching to a lightweight DE like i3.
I've never gotten useful results from powertop. The model it builds to correlate system events vs. observed power usage always diverges with reality very quickly. In the good case it'll just do something a little silly like conclude that the CPU fan is the ultimate source of all power consumption. In the bad case it'll be something like think that a pair of linux veths uses 3kW (not a typo) of power.
I was the same - mixed results at best. I figured that manually playing with this all the time was the wrong solution and installed TLP instead which seems to work pretty nicely. Not sure if it is mentioned in the linked article, so if not then check it here: http://linrunner.de/en/tlp/docs/tlp-linux-advanced-power-man...
I nearly doubled my battery life on linux by zooming on facebook until the chat bar on the right hand side disappeared. Didn't even need to close the facebook tab, just that bar was keeping the CPUs running hot. That's been effective enough for me not to bother with decent trace tools just yet.
I do use the chat though, and every time you click on the chat it brings back the sidebar and requires clicking a tiny icon and a menu option to get rid of it again.
Little-known tip (I think): messenger.com offers a web UI for Facebook chat similar to their iOS/Android apps, also ad-free and significantly cleaner than the actual Facebook UI. No idea whether it's actually better on power consumption though.