Chain types VS MPG/overall cost-small bike
 

O-Ring chains can-not be lubed, they only be cleaned cosmetically.
They were made for the lazy and rich.
Removing/replacing is a $ pain
They have VERY high rolling resistance, a much higher cost and lower life-span due to the fact that they are sealed, and one bad link ruins them. After 5 Oring chain early fails and i learned to back to the basics.

I have 300cc bike, and use motocross non ring chains, and gain 10% MPG rather easily with standard chains.
Standard non-ring chains have master links, which makes removal a non $ issue.
And if one has a spare, can be replaced very easy if one breaks 'out on the road' which has never happened to me in 150K miles. (i do buy new ones occasionally, as a set, so i have two)
But these standard chains actually DO need cleaning and legitimately lubed about every 500 miles.
They last far more than 2x maybe 5x longer lasting than the ring chains, and cost less than 1/2, often 1/3, and even 1/4 of ring chains. Give far better MPG.
A bit more maint time, but if you are 'maintaining' an Oringer (wasting yer time and $) you can do the maintenance on standard chains. Have two (or more), use one, while the other(s) is/are being cleaned, lubed and dried.
Win Win Win.