16.5-17 in town. Best ever on the HWY was 22. Flat ground in Texas and I was doing about 78 MPH.

 

Right at 20 these days... in spite of all the hi po goodies. Highest I've gotten is when everything else was stock and just got smarty. 22-23 then.

4x4 and auto.

 

I get on average 16 hand calc'd. That is with everything on kill all of the time. I mostly drive the truck on two lane frontage and in town. If I add in highway or Interstate but keep the speed down then I see 3-4 better. I run the Interstate for about 9 miles into a bigger town sometimes but I usually run 80 so it is in line with the 16. My truck is in my sig for the info.

 

Disregard one of the 19-23 votes. I just noticed this was for 3rd gen 5.9 trucks not 12V.

 

Around 17 + city,,, some freeway, hand cal.
4 wd, auto

 

18mpg on interstate.

20-21 on highway doing 65 with no wind.

 

18 - 19 mpg back and forth to work, 50 mile round trip, half in town and half on highway at 60 mph. Auto and 4wd

 

Currently average between 18.5 & 20.5 (hand-calc & running my Smarty Jr on 100% POD). Most driving is highway with lots of traffic congestion and stop-n-go. Before the Smarty, I was getting 20 to 23.5 on the same route. I've had the Smarty for 2-years now and never played around with it or adjusted it down for better fuel economy.

 

Marked 15-18. Truck in sig.
17-19 mostly Hwy Smarty Jr on 2

 

15 no matter city/ highway, smarty or not. 15.

 

Pre Jr towing avg 9-12 every day 80% hwy 20%city avg was 17.4 straite hwy 19.2 with Jr everything went up .5-2.3 depending on driving condition, best gains are during towing.

 

I average 17 around town. On the interstate if I keep it between 65 and 70, I'm around 21mpg empty... I have the Jr and 6-sp. Hand calculated of course.

 

I'm 100% stock. O/H lie-o-meter shows 18.3, hand calc. is 13.0 mpg in the city (rural driving). (O/H error of 28.96%) I'm 2wd w/ auto. Hopefully someday I'll get a Smarty Jr.

 

I average 13, give or take 1 MPG. Usually around 10 when I tow. Best I ever saw was 17.5 and that was me trying to get that. Adding the Smarty helped these numbers a little, but not much. I miss the MPG's of my 2003

On my 2003 I saw as high as 22, but probably averaged 16-18 during the time I owned it.

 

I am the guy that is getting 24+ all hand cal (lie-oh meter says 28). I use to get about 22.5, then added a stage 2, spool-aid and exhaust manifold and it jump to 24ish on the last 3 tanks. Now let me say I mostly drive country roads at 50-60 and I have a real light foot, in fact when I do go on the interstate, traveling 70, my mileage starts to drop.



Now for some background, my egt’s when traveling on level ground @ 60 are around 525-575 with 2-3 Psi of boost. When cursing up a hill I will 800 degrees and 5psi of boost. My truck is not “lifted” it runs stock tires and the nose is down low like it came from the factory.

FYI, I turn it up to pull my big trailer and I get 12-13 MPG at 70 (20K) and it pulls it like a dream.

Joe