Hello all, I am thinking of trading trucks and looking at 07 mega auto 5.9 dually with I think 4.10 gearing. I know what I am getting on mine an just wonder what this new truck would get? I usually drive around 68 mph?

Thanks

 

I get between 14.5 and 16.5 on a mix 60 city/ 40 hwy driving, accelerating at like 1500 - 1700 rpm. I only have 5 grand on it though.

 

I picked mine up mon and drove straight home 5 hrs at 130kph and got 15.5mpg. Not bad for a fresh engine.

 

my '07 dually with the 5.9 automatic is getting about 17.5 in town and about 24.5 on the highway if i keep it at a steady 65mph. The taller tires help tremendously in lowering the engine RPM's and increasing mileage. If you are going with 4.10 gears, your mileage is going to be substantially less than a truck with 3.73's

 

Desert Dually, Do you have the 3.73 gears?

 

Is that 24.5 mpg from the lying over head dispaly or hand calculated? The best I've seen on a newer CTD 4x4 SRW SB do is 22 mpg hand calculated on flat land running in the 1600 RPM power band!

 

That is close to my truck and driving speed, the diff. is mine is a late '06 QC. In the 5400 miles I have put on it since last July I have averaged 12.86 mpg hand cal. as compared to something like 16+ mpg that the over head says.

 

that is from the overhead console thingy, but i've compared it to hand calc'd and it's honestly not too far off. I can easily get 730-750 highway miles out of a tank if i keep the rpm's low and steady, at the lowest speed the truck will stay in cruise with the TC locked. I've driven across Texas enough times to experiment with the RPM's and cruise control and speed, towing and sometimes not. What sucks is, the speed limit across much of Interstate-10 is 80 mph, and i stay in the right lane - sometimes at a lowly 55 mph, with all kinds of traffic running up on me and giving me "that look" as they pass me. The mileage difference (as in, miles per tank) is ENORMOUS. I have no idea what the final gearing is now, but maybe some of the math whiz's here can chime in and figure out what 315/70-17's change the stock 3:73's to??? Of course the trip itself takes several more hours at the slower speed, but i have the Sirious satelite radio to keep me company, not to mention the sleeping Mastiff in the back seat.

 

Mine got 14city/17hwy when it was new. I have 17,000 miles on it now and am up to 16city/19hwy. It seems to get much better than that if I can stay at 45mph but there's not much call for that speed around here. I don't think I've ever seen 500 miles on a tank before I was below the 1/4 tank mark.

 

I question that mileage. I'm not saying you are lying, I just find it hard to believe.

#1 - The larger tires will hurt, not help your city mileage. It takes more power to get them turning from a stop, unless the city driving you do is not stop light to stop light.

#2 - Have you verified with a GPS that your speedometer is accurate? There are a lot of people that have used the Smarty to calibrate and found out they had to tinker with it.

I average 15-16mpg and will get 450-500 miles per 30 gallons driving mostly highway. My speedometer is dead on with the GPS.

 

Yes if you have all year to get some place there is milage to be had. My 04.5 dually 4:10 gears auto averages 13 Yes If I drive 55 I may see 15-16. But for my use the truck rocks, I pull a 40 ft toy hauler and I like to speed. at 70-75 wwith my hauler I get 9 -10 at tops

 

All I can say to some of these mileage figures is, "Wow!" I get 13.5 in town and 14.5 to 15 on the hwy at 70 to 75 miles per hour, with the dually in my sig line. Oh yeah, and I get 9 to 10 mpg towing a loaded 24' car hauler.

 

Most of these pople are not in a hurry but even at that I thint the milage claimes on here are way High. My toy hauler loaded weighs 17000.

 

Most of my driving is highway, very lightly loaded, seldom trailering. I found that the Smarty helps mileage substantially if you have it set at the higher levels, but dont get too crazy with the accelerator pedal. As i said previously, I've experimented on numerous trips across Texas, where i can set the cruise and keep the same speed for 9½ hours or so, until i need to stop for fuel or restroom breaks. If you add city driving into that mix, you skew the results considerably, because then you have to average how much of city /highway the fraction is. No, i have not verified my speedo with a GPS, although i suppose i can. I can tell you that after i adjusted for the taller tires with the Smarty, it seems DEAD ON when compared to my buddy's same exact truck with stock tires.

Once, i had a tailwind while heading across New Mexico for several hours, the overhead mileage calculator was reading 28.6 !!!!
Now, i know that there are those here who question the accuracy of these things, but some people on this site have reported their trucks mileage to be very similar to overhead thing. And then there are others who say it reads optimistically. The DTE function has proven itself fairly accurate on my truck, and i think its the same computer that figures the MPG and the DTE. Your results may vary.

 

If I saw the tire you have, its 34.6" in height. Base on a previous calculation for a friend of mine, his effective rear ratio was 3:34:1 that use to be 3:73 in a 2005 Dodge 3500 SRW Cummins powered automatic.

So, if you do decide to tow heavy, keep and eye on the tranny, otherwise it should turn out some good fuel numbers.

Dave