Dealer Using 5-30 as standard oil

[dvkim]

My Local dealer Tustin Acura in So. Cal. has changed to 5-30 as their "house oil". They mentioned that was dictated from Acura through a service bulletin. According to Tustin Acura the advantages are greater fuel efficiency, and more efficient distribution of oil to remote areas of the engine, and small holes? I used synthetic 5-30 last time, so the viscosity does not break down as much on the warm side, However the manuel states to only use 5-30 if you live in an area that never get above freezing. It's not that big of a deal, Can any one comment on this? I've heard that Acura is trying to show better overall fuel efficiency by using this Oil

[David]

That's really odd. Most spec sheets will show 5-w30 is only better than 10-w40 at very low temp, such as below zero F or -20 C.