i cant much avoid idling because traffic always inches forward every 10seconds or so. i have been driving without brakes and with load. that hasnt made much difference. mostly 10.6l/100km vs 11l/100km. but i have had no problems beating the highway mpgs by 30% without even trying, by just using cruise control.
as for cruising i knew drag increases exponentialy with speed, i learned that couple years ago in highschool physics. but i have read people talking about subaru running lean or its best at 3000rpm. I haven't been able to confirm this and plus that means braking the law at 75mph. to me 2300rpm seems the best but that puts me only at 55mph; not too safe for highway. IGN is 42 at 2600rpm going just under 70mph.
ah here is the a/f chart for a 2.5L na
