RCinMesa

I've had a couple '06 srw trucks with 6spds that turned almost 2500 rpm at 75 mph and got a little over 16mpg empty on the road.

Just got back from LA this weekend, and the dually with auto and 3.73s got 14. It gets 13 or 13.5 in town. I thought it would do at least 16mpg with the engine turning less rpms. The truck has 14k miles on it. Is this "normal" for a dually?

Jus Cruisin

Every week or so there is a fuel mileage thread.

My dually started out at 11.xx mpg and now with 4,000 miles I just got 16.3 with mostly highway. Normally 14.xx mixed driving.

djbikeman

Mileage is so hard to compare from one vehicle to another driving different routes on differnt days etc. There are just too many variables including the following:

wind speed
wind direction
ambient temperature
terrain
elevation
fuel quality
MPH
blah
blah
blah

Any one of those things could be why the mileage on the auto was lower. I just put my first tankful in my DRW and it calced to 13.8mpg, mostly city driving. It has been cold and windy around here too.

My 06 Megacab Auto would get anywhere from 15.5-19.5 depending on the variable listed above. I drive I-80 from Omaha to Des Moines about 150 times a year. There is not a flat stretch on that run. I got around 16.7-17mpg on that run averaging 73mph.

Also, lower RPM's aren't the indicator of better mileage, they are just part of the equation. Keep the boost down (>10) and egt's down for best mileage.

rich

7 to 10 loaded running no more then 70 gets worse above that, 10 to 12 empty trailer same speeds, gets about 15 with out trailer running 70 to 80 this the 07 with 30k on it the 03 gets better because its the so with 5spd. your mileage will improve when yuo get about 24k on it

stang

my 05 empty DRW 2x4 48re gets around 16.6 highway, 48 goose around 9to about the best 11.5 speeds of around 77 give or take a few MPH

RCinMesa

I was just surprised that the lower rpms didn't help. I've towed heavy with all three trucks and all have gotten right at 10 mpg - mountains, flat, wind, rain hot weather or cold. I guess the biggest surprise so far has been the very slight difference between driving in town and constant freeway mileage.