Thought I'd pop in and share some info on some testing I've been doing... A few years back I'd been doing a 116 mi hiway run to test mods & tunes for the best mpg in my truck...
Truck details:
2005 Dodge Ram 4wd (then was AT, now MT) with 34" tires,
3.73 gears
2" leveling springs,
tailgate spoiler (no effect from what I could tell),
home made 2nd air dam under the swaybar (helps keep the top half of the diff clean at least, not sure if it helps or not).
60 hp injectors
AFE dropin filter in the stock airbox
stock turbo and exhaust to the muffler which is a 30" magnaflow
ATS Arcflo intake elbow
AFE torque tube (goes between the stock airbox & turbo)
Smarty UDC tune (by me).
Fuel tank vent kit so fillups are to the neck
Using andriod app Torque along with a scantool.net MX bluetooth OBDII interface.
Previous testing was in Northern Cali, filling up at a station just off the interstate, drive 58 mi out to an easy off/on exit back to the original station & pump.
Now a recap on testing back then...
used CC set at 64 mph to control speed, traveled off hours to minimize traffic issues, stayed out of semi truck wakes. Got a best mpg of 22.8 mpg, 22.x was pretty easy on retests. OAT (ambient temps) were in the upper 30's & low 40's with no wind. Back then I got focused on getting IATs up some using a grille block, using a model 1500 bumper insert, 3" tube routed such that it draws air from the turbo area and feeds the airbox area. details might be fuzzy so here is the origial thread if you choose to have a look...
MPG quest... - Dodge Cummins Diesel Forum
Now testing this time around...
Currently working in the Minneapolis area doing a contract and thought this would be a good opportunity to revisit my thinking back then since mpg dropped off as temps headed towards 0*f. Started by adding all of the stuff I previously had and blocked the radiator by about 1/2 to increase engine coolant temps. Discovered that I was being held back by the fan clutch that was getting engaged whenever there was a 25*f difference between the airbox air temp (ABT) and the IATs. Was concerned about unplugging the fan clutch (e-controled by ECU) and getting a CE light (none on the 2005 MY, soft codes set but no light).
ONce the clutch was unplugged I was free to get IATs to whatever temp I wanted. So I then went and made a front CAC front cover (innercooler) out of some marine grade vinyl fabric and some button snaps and velcro (less than $30 bux). Had enough left over to try something I'd thought of for a while and since I was now free to put IATs where ever I choose, I went and cut a piece of the marine fabric to make an intake blankt. This covers the fuel rail & fuel lines (remember, diesel), nothing fancy here, just a notch for the intake horn and a few slits in the fabric so I could zip tie it to the wiring harness to hold it in place. I currently have about 500 miles with it on there and so far, no problems.
Testing... Using the winter blend fuel since everyone says they loose mpg with it and I dont believe they loose as much as they think they do because of it. Found a repeatable 118 mile out & back section of hiway that I can get out there & set the CC to 63 (this time) to do testign with.
plucked from one of the threads...
12/8/2014 117 mi test run on I94
OAT = 27-28℉ for both runs
Fan harness unplugged
UDC tuned, POD = 85
Covers in place: IIATs ~= 90-95℉, CTs ~= 186-188℉ mpg = 20.0 <- shocked it was this high, could hear the fan.
Covers removed: IATS ~= 41-43℉, CTs ~= 172-175℉ mpg = 19.3 <- shocked it was this high, could not hear the fan.
12/10/14 do-over all covers & blocks removed, hose to turbo area moved out of the way.
OAT = 17-23*f, ABT = 17-23*f, IATs = 30-32*f CTs = 170~172*f, 18.4 mpg over 117+ miles
Went to go put the front cover back on and the fan was pulling... CTs were in the 170~172*f range
12/13/14 OAT = 39-45*f, ABT = 65~70*f, IATs = 95-101*f, CTs = 200-208*f mph = 63, POD = 85, mpg =21.3
Cold weather MPG thread. - Dodge Cummins Diesel Forum
The intake blanket has helped quite a bit, the goal of it being to get the fuel rail & lines warmer in really cold temps to help with the mpg goal... bonus was the IATs being a lot higher under cruise conditions.
Anyways, just thought I'd share...
Today
Other popular topics in this forum...
