20.5 mpg Dodge RAM ABA testing run

[ECONORAM]

Okay, took the truck out on a pretty flat stretch I finally found that will work for testing. It was 68* OAT when I started, and was 65-66* when I finished.
Still need to troubleshoot what I fried on the VSS side of my MPGuino, but the fuel flow still works...so I made voice recordings of my stops and starts and set my usec/gal to a ridiculously small number so it looked like I'd burn about 0.3 gal/mile.
Only problem with voice recordings was my Palm Pilot was picking up all kinds of background noise. Next time, I will use my iPhone with the Apple earplug setup--it has a mic built in and you can squeeze it to start/stop. I tested it today, and it does a much better job filtering background noise...
Anyhow, from what I've been able to filter out from my recordings:

First series: AIRRAM air scoop, cardboard ducting direct into OEM air filter box.
IAT 71-73* 6 passes (3 each direction), threw out high and low. Avg: 19.86 mpg

Second series: taped cardboard in front of AIRRAM air scoop (in front of grill), zip-tied flexible 4" dryer hose from radiator fan shroud over and into the OEM airbox.
IAT 89-91* 6 passes (3 each direction), threw out high and low. Avg: 20.97 mpg

Third series: AIRRAM air scoop, cardboard ducting direct into OEM air filter box.
IAT 71-73* 6 passes (3 each direction), but I can't discern my voice from the background noise just yet. Will update when I can. I only deciphered the first run: 19.51mpg, identical to the first CAI run. Otherwise, way too much noise. Even noise removal doesn't help. Sigh.

However, I wanted to see if my mpg change reads okay to you all? True, with the WAI I did have a little more (1/8th) grill block. I was pretty surprised to see a 5% mpg increase though. I do recall somewhere around 80-90* IAT my truck seems to lean out slightly; at least that's what I remember from driving around north Texas the past two years. Thoughts?


[edit] Cruise control set at 61 mph. It pained me greatly to drive back home, leave the truck idling while taping cardboard on the front or removing it. I dislike idling...but wanted to keep the exact same cruise speed. Winds were out of the south at about 7 mph, a crosswind on the road.

I did the math and it seems I have a 6.6% increase, not 5%. Seems consistent with other MAP vehicles: http://ecomodder.com/forum/showthrea...tml#post343583

[ECONORAM]

So I re-examined the aero kit and brackets this week, and realized I made a big error. I originally tried to just make the panels flush with the frame rails and the body seams. However, I've discovered that makes for a poor design with my truck, as they are not level with each other, and the frame has some hoops and dips. So I spent a few hours Friday remaking the brackets to hold the left panel between the frame rail and the body...and then reinstalled the left side panel. Now the panel is horizontally level with the center panels. This, along with adding some filler panels around the front tires that are also level with the center panels, WAI, wheel fairings and 3 more psi in the tires (39.5 front, 38.5 rear) helped me hit 21.6mpg driving up to OKC this weekend. Admittedly, I still need to formally test it but this first drive is promising. This was also on E10 fuel.

The truck would previously get just over 20mpg in 4th or 5th, but with the modified aero kit I now see over 30mpg in 5th at 40-45mph...

I am seriously considering a daily fuel log--Thanks DieselDave. With this, modifying my driving habits some more and some rearranging of my daily drive to avoid morning rush hour, I think I can push my avg mpg to 30. I find myself wondering how much farther I should drive in order to achieve this goal...

I also did some Google searching and learned I can leave my block heater plugged in for extended periods. Previously, I thought I'd risk cooking something, so I've almost never had it plugged in more than 20 minutes... Gotta thank MetroMPG for posting stats on temp rise: Experiment: how long should a block heater be plugged in? - MetroMPG.com So, I will be setting my timer to run for an hour, maybe 90 min before I take off in the morning (at least in winter). That should help mpgs, as my truck hits 2 gal/hr of FF for a cold start, then down to 1.6, then down to 1 or .8 for a while.

[radioranger]

going oversize on the tires might help more on a manual , since you can run a bit less rpm around town I figure once your moving, sort of a half or 1/4 gear size up so to speak, sometimes i cant get into overdrive around town , also isnt direct drive going to be more efficient if the rpm is right due to transmission losses of the extra gears spinning in the trans. if sized right could save on clutch wear since shifting less, might not apply in your case , my little 5 speed 4 cyl ranger is only 88 HP new . course it's 25 years old next week and 400 k to boot, so all around real happy with it .

[slowmover]

One of the diesel gurus has the rule of thumb that, for block heaters: 90-minutes for 90% of the benefit. This, from a guy who lives in Idaho.

Am learning from you on bellypan. Congrats on breaking 20 so nicely.

[ECONORAM]

Originally Posted by radioranger

going oversize on the tires might help more on a manual , since you can run a bit less rpm around town I figure once your moving, sort of a half or 1/4 gear size up so to speak, sometimes i cant get into overdrive around town , also isnt direct drive going to be more efficient if the rpm is right due to transmission losses of the extra gears spinning in the trans. if sized right could save on clutch wear since shifting less, might not apply in your case , my little 5 speed 4 cyl ranger is only 88 HP new . course it's 25 years old next week and 400 k to boot, so all around real happy with it .

I have looked at that, but it seems tires any larger in diameter than the OEMs (33inch) weigh another 10-15# each!? If I had the (scarcely) available 6-speed manual, taller tires would certainly help, as 6th in the manual equals 4th in my automatic. A manual swap is still on the to-do list.
Do you slip-shift? That will save you clutch wear. I only use(d) the clutch when starting and stopping. The rest of the shifts I just modulated my right foot to hit the next gear...
I've been reading your topper project. Nice work!

[oil pan 4]

Originally Posted by slowmover

One of the diesel gurus has the rule of thumb that, for block heaters: 90-minutes for 90% of the benefit. This, from a guy who lives in Idaho.

Am learning from you on bellypan. Congrats on breaking 20 so nicely.

I run two 650w block heaters for 20 to 30 minutes. Running 2 block heaters for 20 to 30 minuts seems to match about what you get from running a single block heater for an hour to 90 minutes.

[justme1969]

I feel your pain! Dodge trucks suck gas. My dakota rt has gotten better than stock mpg but It wasnt easy. and generally it feels non existant.
I am now fighting with lock up drive train issue, the trans now does not unlock during decel over 45mph. thus all coastdown is gone. either in throttle or out sorta like a circle track car. It is a blast to drive but not an econo cruiser just muscle car.

[radioranger]

Well I get around 200 K out of a clutch normally but the tranny is pretty well worn so got to baby it, I put the larger tires and wheels from my 98 ranger I had last year on it and it seemed to roll a bit easier than on the little 14's so soon as i can find some cheap may try two 15's on the back, was thinking of lowering the rear two inchs and then the one inch or so taller rear tire should match well and give me a bit more flexibility in 4 th , I have a 3.45 rear dif so should become a 3.25 or so equivalent, ideal I think , I had an idea today to trick one of the sensors, suppose you put a small tailight bulb and socket near the air intake temp sender , maybe warm it up a bit faster . switch off on dash if warmed up . .

[justme1969]

These dodge engines are grunt designed. You thought of replacing the cam is good one.
I have the 5.9 rt and nearly same gas mileage so I feel for you. My best mod was the trans.
Get a shift improver kit or such to shorten the slip time. Ive got the Mega viper trans kit installed in mine and it is like whole new truck.
I worked many similar angles to see 16mpg. this is my truck and play toy not daily driver.
So my approach was better use of fuel burned and less rotating mass etc.
I got more power and better delivery of it thus better mpg when my foot is on and off the floor.