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Did a lot of work on the Ram over the years... took it from 18 when I bought it all the way down to 12 with the suggested mods everyone was doing at the time. Got tired of spending more time at the pump then at home so at one point decided to bring it back up and try to get up to 20 mpg's. At that time I still had the AT in there and got on a mission to improve it. Long... long... story short, ended up getting it all the way up into the mid 23's on a regular basis this year. Had something like 12~15 tanks above 23.0 mpgs. Back around the winter of 2017 I started a "makeover" on the truck and documented what I did (linked below). Took it from upper 19's at the time to where it is now, every tank is easily getting 22 or better and the last time I looked at a 35k snapshot, the average was right at 21.0 mpg over those miles.
Not so cheap airbox mod, plan to look into implementing this on the Dak... would use a valve that is vacuum controlled that is closed under higher vacuum conditions. Airflow thru the box matters, the cheap version I did was an $8 trailer vent on the bottom of the box. V2 was an electric exhaust cutout and then finally the boost controlled version was the by far the best and is on there now. https://www.cumminsforum.com/threads...#post-29500042
Aero mods... I tried a lot of stuff and ultimately the best bang for the effort was the 2nd air dam under the front end and the side bed seals (would need to use a tape on type of seal on the Dak), I plan to do both of these on the Dak. I learned a ton about aero on the truck, what causes drag, increased down force and overall stability. I have probably tested about 3/4 of the ideas which lead to the fun in the sun. https://www.cumminsforum.com/threads...#post-27628738
Engine performance... Will be focusing on mods that improve bottom end torque and power up to 3~3.5k rpms.
I can document the effort here if there is any interest. My first tank gave 14.4 mpg's, (little woman was so happy to hear that btw, he Jeep JK gets 15's and did not want to have the worst mpg performing ride in the barn), mostly city miles and that 10 mile loop I was doing. I'd want to get that up into the 16-17 mpg range with hiway closer to 20~21.
If there is anyone who has dove into this on the Dak, I'm all ears and would be interested in hearing what was done.
mpg's stabilized at ~15.6 mpg's after internal engine cleaning & plug swap <- this is the starting point for improvements. I have had 3 tanks in a row at this mpg, all "eco" driving.
mpg's, 2 tanks now at 15.98x mpg, new plugs went in for the last tank.
Sorry, have not been posting links to updates, this picks up at the end of January, truck was down for about 10 days when I thought it would be fun to erase the ECU and not have a backup ECU... whoopsie...
Mileage data... Any interest here in better mpg mods? - Page 9 - DodgeForum.com
Last edited by steve05ram360; 02-02-2022 at 08:15 AM.
I'm interested and looking into this, only mod i did for fuel saving is the 45rfe to 545 rfe mod.
I've got a 2000 so i got all the bells and Christmas tree up on the dash, but lowered my rpm's by 300.
I drive larger back tire's so rpm's got down a bit there.
Other mods are an cold air intake / open air filter and a free flow 3 inch exhaust from cat to back.
I'm doing 18 mpg but only at 60mph, the current speedlimit over here.
I will read you're other threads about this, because i'm rather have torque aswell instead of high rpm horsepower.
I do pull a trailer occasionally and it's more relaxing to drive this way.
Right off the bat you could go do the bed seal mod and should see immediate change in drag... below is a pic of how I did it on the Ram. You would need to find an appropriate seal and good double back tape to get it in place on the Dak bed... You want to take the seal down to the upper part of the bumper, look at the body line on the ram pic and how it meets the top of the bumper. If you go below that line (on the ram) the bumper becomes a parachute and will add drag. $20~25 bux for the garage door seal and tape at home depot so ROI is quick. Mount the seal on the bed and do not allow it to touch the cab. You would have to look at the seal to see how the coverage would be. On the Ram, I used a seal off a 2014 or newer 1500 Ram. Slides on in seconds. There is no lip to mount this type of seal on the Dak bed.
IIRC there are already 2 smaller seals between the cab and bed.
I will try tomorrow if i could make this mod, so between the cab and the bed, from the top of the bed to the line as you described.
The rubber seal may not touch the cab ? why is that ? i have some seal laying around, but i think it's to wide and it will touch the cab, maybe i will cut it so it's clearing the cab.
Looked into you're thread on the cummins forum and saw the picture of yours.
the seal will rub the paint off and opens the door for rust. Also, minimal benefit to getting it that close, the air flow down the side would get disturbed and detach from the bed and become turbulent which causes drag. On the ram I have an approx 1/2" gap to the cab from the edge of that seal. Noticeable change in drag in the seat of the pants feel.
IIRC there are already 2 smaller seals between the cab and bed.
I will try tomorrow if i could make this mod, so between the cab and the bed, from the top of the bed to the line as you described.
The rubber seal may not touch the cab ? why is that ? i have some seal laying around, but i think it's to wide and it will touch the cab, maybe i will cut it so it's clearing the cab.
Looked into you're thread on the cummins forum and saw the picture of yours.
I did mount them already, but i didn't drove it yet, i'm at holliday rightnow, monday i'm going to work again and i could see if i could notice something.
On the Dakota there is a rubber strip on the bottom front side of the bed, between the cab and bed.
At the Ford Rangers there are 2 on the side between cab and bed.
I've read about you're other post and i knew there was a engine cover missing under the radiator/engine.
So i've been changing my oil and made myself a new cover under there.
I've seen you made an airdefector under the Ram, but because of the bad weather, rains all day around here, i'm looking into that and make one later on.
I did mount them already, but i didn't drove it yet, i'm at holliday rightnow, monday i'm going to work again and i could see if i could notice something.
On the Dakota there is a rubber strip on the bottom front side of the bed, between the cab and bed.
At the Ford Rangers there are 2 on the side between cab and bed.
I've read about you're other post and i knew there was a engine cover missing under the radiator/engine.
So i've been changing my oil and made myself a new cover under there.
I've seen you made an airdefector under the Ram, but because of the bad weather, rains all day around here, i'm looking into that and make one later on.
If you have a way of data logging the calc load and have a rolling hill route you could test the seals before and after, look at the data to see if there is a change in the calc load. That is what I plan to do when I get to it. One thing I noticed the other day looking at it, if you have the wheel well flares on there, it might actually cause drag right there so it might need tweeking. On the horizontal bed seal, on the ram I found it caused additional drag, enough that it was noticeable. You might also want to play with that one as well. I did not see on on my Dak but I still plan to test it as each truck design is different.
on the 2nd air dam, yeah that was one I tested back to back to back, no air dam, v1 of the air dam, & v3 of the air dam. V1 proved to be the best. Then, 2 years later while replacing it I found one side was too wide by 3 or so inches... it was dumping air into the back side of the passenger side tire and causing drag. fixed it but could not really tell if it made a difference. I just know from testing the V2 version that if it is too wide, it will dump into the tires and cause drag. Have not looked yet to see how one could be installed on the dak.
Do you have the 45RFE to begin with ?
I have the 2002 TCM 56041905AD on my 2000 Dakota.
On 2001 to 2004 models there shouldn't be no problems at all.
You need the TCM of a 2002 till 2004 Jeep Grand Cherokee and just change it over, the 2004 will be the best because off the upgrades.
It will drop you're RPM's by 300, there are different results in MPG, if you do a lot of highway than you'll gain the most, there are complaints of coming out of OD when going uphill.
Also a lot city driving could get you at higher MPG, and it's affected with tire sizes especially on 4x4's and differential gear ratios.
10-05-2021, 09:00 AM
Any interest here in better mpg mods?
