better engine life = definitely yes ..
but fuel economy difference = negligible in short term .
the difference comes in notice after around 100k - 150k mileage ...
brands like valvoline and amsoil are top notch brands , their oils are made to last very very long. and also the engine protection , hence very long engine life.
but IMO for a small economy car (and also per my pocket ) .. they are overkill i think. LM is like in middle, not too expensive.
if I had may be aqua, prius , grande, etc then i would definitely go for 0w20 LM or valvoline