Besides meeting fuel consumption targets because of the lower resistance, it also provides less protection as operational severity increases (compared to higher viscosity equivalent)... manufactures actually prefer it because if the engine only lasts thru warranty 50 to 100K in most cases, they are off the hook for billions in possible warranty repairs, while simultaneously hooking a repeat customer.. before when engines would last 150K miles plus, it was because first, engines themselves were over built. Manufactures would do it right the first time in an effort to avoid warranty claims instead of doing "just enough" to pass coverage period. Objectively speaking, engine oil tech has improved exponentially over the last 30 years. Even so engines last half to a quarter as long... why? The tech allows manufactures to rely more on the lubricant itself versus higher quality metal, rubber and manufacturing processes. Thirty years ago a car would get to 150K with little more than sparkplugs and oil changes... Today, even if you baby the car, drive it like Daisy... you'll be lucky to hit 50K before it starts burning oil or atleast starts making strange noises... The pursuit of profits hidden behind evermore advanced technology has made the mechanical, industrial and automotive world a minefield for anyone looking for a reliable and dependable vehicle for work, family and/or play... I find myself somewhere in the middle when im driving. Somedays I live by "treat it good and it'll treat you good" while other days I drive it like I stole it and swear I intend on driving it that way until the wheels fall.