I would like to do a comparison on MPG (hand calculated only) on my truck compared to a similarly equiped truck. It sure seems like others are getting much better economy than what I get. The only addition to what you see below is: 3.73 ratio, 4X4, the EZ set on #1 (seems to give me the best MPG).

In town driving is right at 15 mpg or 500 miles on a tank unloaded.

Highway driving at 75 mph yields about 19 mpg unloaded.

Towing out 8,000 lbs travel trailer at 65 mph equates to 11.5 mpg.

If these are way lower than what you get, do you have any suggestions to improve my mpg?

 

That is not horrible. Although, with 37's on mine and a 6" lift im getting about the same/maybe a littler better sometimes. When I tow my jeep on the tractor trailer (about #7000) I am getting around 15-16 MPG. Unloaded getting 19-20 MPG.

 

your getting better than me.. in town im lucky if i get 13.

highway i get 16.6.... so dont feel bad my truck sucks, and im easy on the throttle 90% of the time

 

You didn't include how many miles are on your rig...I got my last increase in mpg at 80,000 miles. Mine is an '03 manual 6-speed. the best setting for me is #4 on the e-z. On the freeway, unloaded, it has gotten up to 24.3 mpg. That was figured with a pencil, not the overhead display. I have 4:10 gears, and 35" tires-rpm's are about 2150 at 75 mph. speedo is off by 1/10th due to tire size. these engines take quite a while to break-in, be patient. Towing, the mileage drops to about 14, but it's a big trailer so the wind resistance and the weight requires 40% more fuel. It's still WAY better than the d.p.f. series. Cold air intake, and free-flowing exhaust gave me about 1.5 additional miles to the gallon.

 

Oh yes, Thanks DieselDean, my mileage is at 40,000. That is a great point that I have not thought about lately.

 

Once the block has seated the mileage should increase slightly. This is around 80,000 to 100,000 miles.

My 2002 (different to this topic) has mileage all over the map. If I drive in town, I'll be lucky to get 15 - and I mean lucky. All hand calculated. Open it up on the freeway and burn out some of the carbon and it shoots right up to 28, even with the stage 5 sticks and the Smarty on 5.

I really think that it has to do with where you drive it almost more than how you drive it but if different people drive it - like say the wife and I with the new R320 - she gets 28 if she's lucky and I get 37 - we both drive fast, i just don't stomp on the skinny pedal.

Mileage as a result is very subjective. Oh and don't trust the lie-o-meter on the overhead in these trucks.

 

Diesel Dean: I have found out that the tires on Dodge trucks(at least 03-07 that I am aware of) Tire size does not affect the speedo. I had 33's on my truck before I had the 37s and I always thought my speedo was off for months untill I hooked the gps to my truck and it was spot on. Called around to some Dodge houses and they told me that the speed sensor is in the tranny. According to them tire size doesnt matter but gears do.

I could be wrong though, as not all dealers are always right. In my case it was correct though.. for once

 

I have checked the miles registered on the odometer against the test section (5 mile area marked off w/ milemarkers) and also with two G.P.S. systems (garmin "rhino" and tom-tom) All indicate that speedo - odometer are off by 10%. If the tires are turning fewer revolutions per mile, then so are the gears. Some programmers have a speed correction function, but mine's not one of them. Maybe the difference in our readings has something to do w/ Manual vs. Automatic transmissions? When I ran the speedo up to 100 mph, both G.P.S. systems registered 111 mph. (tach was in the red too!) That was between Reno and Vegas- long and boring unless you're trying to outrun a Duramax. Anyway...might want to verify your info, it'd sure suck to get popped by the Highway Patrol for an error in speedo reading. My Dad runs 33's on his rig, and his speedo is only off by about 3%.

 

Huh, that would be a new one on me then! I have ran my truck next to friends stock cars/trucks and mine still reads "correct". Mine is an auto by the way. Im sure everything differs a little bit, but thank god for radar detectors

 

I can't see it being in the transmission as it is a computer entery on the star system as well as say the smarty programmer.

Using the smarty I have my 285's (32.5" tall) set up spot on.