is amzoil synthetic better than dw1 as it relates to flow in transmission?

 

Maybe. The thing is, flow is the least of your concerns with regard to a Honda transmission. Why? Because Coefficient of Friction (CoF) is the single most important factor in ATF; if the CoF is too slippery, the clutches slip and wear prematurely, conversely, if the CoF isn't slippery enough, the clutches grab too quickly causing damage not only to the clutches, but the rest of the internals in the tranny. Given neither Amsoil or Honda publish their CoF numbers, there is no way of knowing how close (or not) the CoF properties in the two ATFs. Said another way, why screw around with an "unknown", the Honda ATF (currently DW-1) is the only "known" ATF for Honda automatic transmissions.

 

Lotza discussion about the DW-1 alternatives among the many Honda forums. As for this stranger, I use DW-1 exclusively, and I use a consumable inline transmission oil filter to keep it yummy.

If the expense of Genuine Honda ATF is the motivating factor for considering alternatives, I find Majestic Honda has the absolute best price for the stuff, including <gasp!> reasonable shipping! ...$5.50/qt and $10 to ship a case!