The tuner is your best bet as it will give a little MPGs, the most performance gain and you can fix your speedo.

As for the others you are thowing bad money at bad money if you are doing it just for MPGs. TB spacers are useless. CAI.... Lets thow out some #'s.

Lets say you get 1MPG increase (which you will not get that much). That is an additional 26 miles per tank, which would be about 1.5 gallons saved per tank, or $4.50. That would take about 27K miles to break even. Again, that is with 1MPG gain, it will be less than that. .5 is realistic, so figure about 50K miles to break even.

 

Only mod that I've found to pay back in gas savings in a fairly reasonable amount of time is an e-fan. Especially if you go with the pic 'n pull type fans.

 

I had to go back and check your threads for a refresh, but I remembered you changing your gears out to a set of 4.56's when you put your 35's on...wise decision, lol! Had you not, your gas mileage would have sucked too...same as countryboys. Not changing your gears out when putting 35's on is like putting a 300 dur 600 lift cam (4speed cam) in your truck without changing the gears to match the cam...it is a MUST. The race car would then take off slower, loose power, and get crappy gas mileage and would be slower in the quarter mile than it did at stock...same scenario putting on 35's. Cowboy needs to do the same thing to bring his gas mileage up within a reasonable range. He won't get the same gas mileage prior to the 35's, but it will be a big improvement over what it is now, lol! At least to 4.10's but even that isn't quite enough, he may has well go with 4.30 or 4.56's. Then he can go from there trying other options to improve it even better...don't you think? IMO...it is a MUST to change the gears out when going from stock tires to 35's or you'll get poor performance all the way across the board, just saying. PS...plz don't shoot me, lol!

 

I know of a guy who on his 03 dakota 4.7L has both I believe the e fan was for when the a/c came on but not sure anyway he took out the mechanical fan and is just running the e fan , not sure if any rewiring took place, he put a magnaflow muffler on the single exhaust these two improved his mileage by I think he said 5 mpg's

 

Get a Smart car and put it in the bed.

I lost 2.2 miles per gallon with a lift and 35"s. getting about 14mpg now.

 

i used to complain about my milage i was getting. i used to be around the 14mpg on good days but now i get like 17/18 mpg and i dont drive slow. im usually between 75 and 90 mph or 120 - 140 kms/hr and i have 37" tires and a 6" lift. i have a diablo programmer and when i was on the 89 tune, i was getting terrible milage but with the 91 tune i get good milage. i have an afe intake and i cut out the huge monster muffler and just put in a pipe. sounds great, and lots of people complement on the sound. so if flowmaster is not good and you want sound you can always try that. did notice smoother shifting on the 89 tune. my trucks got the 3.55 gears that come with the laramie so maybe you would rather a sports gears. my old sport got better mpg so those maybe helped.

 

Wow, do you really drive 90 MPH with a truck like that? I don't think we can stay out of jail very long doing that in the US.

 

i try to stay within 20 of the speed limit but flow of traffic i try to keep up to too. i was doing 140 the other day and being passed like i was standing still! anybody in alberta knows the hwy 2