The most recent poster got reamed for complaints about fuel mileage I see. I can't complain about my 22-24 mpg average in AZ mostly high speed highway use. The unusual thing to me is that I get better mileage driving hard and fast in manual-auto mode than my wife gets with her <65 mph top and feather foot city full auto mode use (full tanks have been tested, with me using another car). That is odd to me. My previous BMW 328 (1999) with manual trans showed big gains for feather foot driving. Perhaps that is one reason why some calmer drivers may find the TSX's comsumption unusual.

 

I wonder how much(if any) the dbw system plays into this.

 

I think you both have some of the reason for the milage. In a recent study somewhere in Europe it was found that you get the best milage when applying the throttle about 2/3 of the way (this is before DBW) and accelarate "briskly" to the desired speed and then get in the highest gear possible and cruise at that speed. I guess the feather touch for a long time vs. the punch it method consumes more fuel.

This is even more evident on hybrids because once at speed, hybrids switch to the most efficient mode. This is why virtually no one can get the EPA figures with the Prius; most of the folks that bought it, got it for the milage and are feather footing it. You gotta be deliberate and get to desired speed quickly.

 

I find the same thing with my 6MT. I get better mileage when I accelerate fast and quickly get into overdrive gear than if I drive it granny style. I basically shift from 1-2 and 2-3 at 4000-4500rpm and zip through the other gears quickly all the way to 5th or 6th (this is city driving).