Gs400 "d" Or "m"

[briggs400]

Anyone noticed a difference when playing with the button shifting as to fuel economy? i mean i guess if you hold each shift until 4500-5500 rpm your gonna lose alot of gas mileage. but i have never driven a tank of gas from full to empty using the manual shift mode.

im asking cus im doing a long road trip to the lake....385-400 miles and im looking at making that tank of gas last as long as possible.

also...i know that with older cars, using the A/C used to absolutely kill gas mileage, but is that still the case any more?

i know these all sound like juvenile questions, but i have never really payed attention to my fuel economy before. i know roughly how long a tank should last based on my driving habits.

any input would be appreciated

thanks

[SKperformance]

Using the A/C in any car will lose milage no matter what the year.

Auto is always going to give better gas mileage.