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.

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 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.