How to improve Dodge Ram Van from 12mpg? [Belly pans?]
 

Hey everyone, this is gonna be a fun project.

I happen to own a fullsize Dodge Ram Van. 5.2L V8, 4-speed automatic, LT235/75R15 Severe Snow Service tires... this thing was designed for towing and cargo, not high efficiency.

This spring I'll be restoring it. Ripping out the interior panels and putting new insulation and carpet in, painting the exterior, and while I'm there... I want to do something about the fuel economy.

I've spent plenty of time under that van. There is a TON of space underneath. I don't even need to jack it up to replace the shocks, I climb underneath and there's 28" of space from the ground to the floor panel.

Everybody who has done belly pans has been on more efficient vehicles. I mean, one of the cars tested was already getting pretty near 100mpg... so belly pans can't help much more than that thing is already doing. Right now, during winter, I average 11.8mpg. During summer, I get closer to 15. "Driving variances" doesn't really apply, it's ALWAYS 11.75 to 11.83 mpg, no matter how I drive.

Considering the significant amount of space under that van, I'd imagine it has absolutely horrible airflow. Even if I could squeeze 0.5mpg out of some coroplast-crafting, that'd be pretty decent. I don't know all the details of the design though, especially around the tires.

With the front control arms and rear axle, should I be encasing them (jacking up the van so I know the lower limits of the control arms), or should I just have the pan angled to have the air "jump the gap"?

Lots of pictures to help illustrate:
License plate is well-deserved
Front suspension can't be good for airflow.
Exhaust doesn't hang that low anymore, but still gives an idea of body height. Doesn't show floor height
Goes with the above picture, this is how high to reach the bottom of my frame
View looking from the middle towards the front. Poor airflow I'd imagine
View looking from the middle towards the rear. I'm sure this could be improved, even if I have to ignore the area with the driveshaft

As you may have noticed, some pictures are old and that van has been modified numerous times. Usually on a really low budget (lol tailpipe? more like failpipe) but this time I want to do things right.

But you guys are the experts on this. What would you all recommend?

Air dam on the front perhaps, but I own a 01 dodge ram crewcab v8 (5.2ltr) it gets the same FE as your van 11 city 15 highway.

I am able to get a little above 18 highway using a scanguage and fiddling with the throttle.

I can also get 20mpg city if I have lots of rolling hills and situations where I can almost coast to a stop. Normally though I can only do about 14 depending on how far I have to go and how cold.

The 5.2 dodge in neutral coasting gets about 20mpg right down to 10mph, so needless to say coast almost to a stop to improve FE. You only need to be moving about 5mph to get above 11mpg in neutral once the motor is warm.

Another thing, GET AN ENGINE HEATER. The 5.2s hate cold weather and use over 2gph of fuel just idling when its cold and the FE crazynes continues a long while after you get going until the motor heats.

Also I've found on my 5.2 that the truck takes off SSLLOOWWly if I just press the accelerator pedal in, if I waver the pedal in and out a small amount rapidly just before I take off in earnest the truck takes off much more firmly and at better FE, another thing if you are accelerating, just accelerate fairly hard the 5.2 gets about the same FE accelerating hard (assuming you did the pedal trick) as it does accelerating slowly.

Good Luck and its best to test with a scanguage

Anyone tried boat tailing on a van? I don't think I've seen it yet, but a partial kammback on the top and sides might help.

It should help if you install summer tires after winter is over. Snow tires usually have high rolling resistance. Check if your ignition timing is correct. Make sure the engine warms up to normal operating temperature. If the heat feels weak you might need to replace the thermostat. Check the output from the oxygen sensor to see if the fuel mixture is correct. It should have about 0.5 volts after it warms up. If it's not working right it should turn on the "check engine" light. Replacing the oil in the differential with a slightly lower viscosity synthetic oil should help in the winter. There's a lot of other things you could check out. Read about the 65+ Vehicle modifications for better fuel economy - EcoModder.com if you haven't already.

You can do better than 11.75mpg with a stock 5.2 even in town but you need to rework your route usually. You also need an engine heater if your trip is shorter than 10 miles or you simply can't get the things to do better without extreme measures driving wise. I would estimate that this motor even with many aero mods would see little benefit in the winter on short trips without a magnetic or gel blanket heater on the bottom to keep things warm

Also how much air pressure do you have in the tires? I can get about 2-4mpg better with 60psi (depending on how far I am allowed to coast and what speed)

Your vehicle has a lot of inertia even one stop and go reduces fuel economy even on short trips by about 1-3mpg as measured by my scanguage. Think about the number of times you stop and from what speed. Think of the # of times you have to use brakes. The potential fuel economy on this vehicle is only around 18mpg-20mpg steady state & better P&G, even in the winter but you can't actually reach that except if you have a long trip with no stops.

The main issue I have with my trip is that I can't coast far enough on my trip into work and around oshkosh. To get 20mpg you need to be able to coast down fully at every stop. If you ARE NOT COASTING DOWN TO 8 MPH you are not getting your full FE potential and stopping straight from anything above 20mph kills fuel economy massive (I am talking experience)

If your vehicle is OBDII beg/borrow a scanguage if you can afford it. You will see there is a lot to be gained on a 5.2 from driving technique alone, especially at lower speeds.

One last thing, if you coast to a stop always coast in neutral never in drive, dodge has the motor set to burn more fuel in gear; sometimes on the highway almost double in gear compared to neutral.

Lastly this post was not to discourage you, I am just stating facts about your vehicle, aero is only going to be the most effective if you can get the motor warm and only if you are driving about 40/45mph much of the time. Grab the low hanging fruit first. If you have a lot of stops you need to be able to coast down as much as possible regardless of your aero situation. And lastly 5.2's don't like being babied when you accellerate, either accelerate or drive a steady speed but nothing in between when you are in gears below 3rd. Generally firm acceleration but not to the floor accelleration. And don't diss wavering the accelerator pedal before taking off from a stop, its worked now in 3 dodge vehicles, must be some strangeness with the computer and slushbox.

Good Luck
Ryan

Wow, just woke up and already tons of great information! I'll have to tackle these one at a time...

@rmay635703:
Unfortunately the only similarity between the trucks and vans is the powertrain... You didn't mention if yours was 2WD or 4WD, and that obviously has an impact on weight differences. We both seem to get the same mileage, but aerodynamics is my focus at the moment, and our vehicles are too different in that regard :)
It's been running Mobil-1 Truck/SUV oil for a while, but a lot of people are suggesting I switch to Valvoline, which I plan on soon. I've done some little things just to make the engine breathe better (Dynomax exhaust, modified the intake manifold, 180° t-stat)
As far as overall powertrain health... the engine was replaced with a warranted 80,000 mile engine a couple months ago, transmission was rebuilt 2 years ago, and the axle was serviced and swapped to limited-slip months ago... so everything should be good.

The old engine had a heater but it didn't help much. Maybe I need a bigger one?

@Andyman:
Tires are simply too expensive for me to keep two sets, plus getting ahold of another set of four chrome factory rims is a challenge. There's also few options for LRR truck tires... that flying brick weighs 5,000 pounds, so it needs strong tires. Thermostat is good, heat is enough to make me sweat in below-zero outdoor temps... It's OBD-II and my check engine light is off. If I use a code reader I only occasionally get a "Transmission Temperature Out Of Range" (too cold, not enough to trigger a CEL)

@rmay635703 (Again. Didn't see the last post):
Right now I have my rear tires at 45psi, front at 42. They're rated for 55 max cold. Also, you work near Oshkosh? I'm just south of Fond du Lac, and I drove up to Oshkosh every day for work! I've noticed the engine "feels" more efficient giving it some gas, not just babying it. I installed a tach to keep track of engine speed and I usually have it at 2000rpm (±100) when accelerating until it hits overdrive. At 2,000 those engines put out 105hp and 275ft-lbf of torque, so they definitely have some power available!

I'll at least try smoothing out airflow leading up to the control arms, and I will definently have to try the wavering. A good portion of my drive is up or down a large hill, so neutral coasting sounds like it could be helpful. I wonder if the wavering at a stop improvements has to do with the low idle speed... mine idles at 500rpm, but wavering the gas would bump it up to 1,000 before trying to move the car. I'd imagine if you don't waver the pedal, trying to accelerate from 500rpm is just wasting gas.

Hard to discourage me when I've got nothing to lose trying :)

Our vehicles are much more similar than you can imagine, mine has a cap and actually has WORSE aero than your van, mine is 2wd and approx the same weight.

Try to air the tires to 60psi and suffer the ride, assuming you aren't driving in tons of slush.

Also I have been known to place a magnetic heater on the transmission :) Both the motor and transmission need to be warmed, best to place a blanket on the oil pan and transmission or if you have a garage :) You do need to make sure the heater is the type that can't burn anything though.

Also these vehicles do quite well up and down hills, unlike most here I burn going up the hill, throw in neutral before the crest and coast down. Steeper hills work better and my scanguage shows a definate improvement done correctly. Remember though you need to map out your trip, neutral coasting works best for me around 35-50 mph and you don't want to loose huge amounts of speed so if the hill is insufficient it won't work very well except at low speeds both around the hill and through the hill.

Also wavering the pedal a small amount before taking off seems to make my truck grab in and take off harder with much less pedal, you can actually feel the motor pushing harder with each small movement, it might only apply to those of us who need a tuneup but both my friends and my 5.2 behave that way. I have always known on OBDII to push in the pedal slowly when you need hard accell instead of just slamming, perhaps its computer/sensor related?

If it works for you free tip :) I get around 5mpg accelerating when I do this instead of 1mpg accelerating when I just push in.

Also aero is very important but equally so is technique, trouble is if your on highway speeds AKA 40mph+ the only thing you can do is drive really slow and gently press your pedal in going down slight inclines and slowly and gently release the pedal going up minor inclines. This is how I can get 18.5mpg. Without I get a tad below 15. Faster than 55 is troublesome for FE in these rigs unless you have a tailwind.

Good Luck, the only direction you can go is up :)

bellypan
 

The sticky with seminars and mod data has a section on bellys.You might get some quanta there.
CAR and DRIVER attempted a bellypan on a Dodge van and it was basically a wash.They surmised that only an intricately crafted pan would be effective,something they were not willing to take the time for.
All vehicles will behave differently.

van boat tail
 

18-inches of tail on a VW Transporter was good for about 4-mpg at 55-mph.

"Driving variances" always apply. You can aeromod and engine mod to your hearts content, but it has been shown over and over on this site that the biggest improvements come from adjusting the way you drive.

my buddy had one of these it was a 98 ram van with the same motor and it got 13 city and 17 highway
Driving style will make a big difference

Driving style change would be good
Roof rack removal would make a small difference
Remove some of the junk inside of it would help
Grille block would help since yours is huge
Air dam would help
A vacuum gauge would help you learn to ease off the throttle

it just all depends on how much you want your car to look weird (boat tails, kambacks, wheel covers, exc.) and how much you want to spend (scan gauge II would help alot)

Whoops. New mouse has those side navigation buttons and erased my entire message :C

I've read that the grillle block from the inside would have no benefit, but I can't bring myself to cover my shiny chrome grille from the front...

Domman, the 98-03 had a redesign to be a little more aerodynamic. Sadly my 96 only had first-gen-aero-smoothing.

Aerohead, did they do it on a fullsize van, or one of the minivans?

Take great care implementing a grill block on these rigs, the blasted things love to overheat for some reason, especially the unddesigned transmission. I would simply make sure to have a decent temp guage for both the transmission and motor before doing this (and pay attention to them). In the winter you are gonna get away with a lot more unless you drive 100+ miles.

And I 2nd an air dam, with an air dam you should be able to block much more of your grill and reduce wind resistance under the van, lowering the van also helps on this. In other words there are easy ways around needing a belly pan.

And i massively agree on a scanguage or vacuum guage. They let you see visually & compare what actually works to what doesn't. Driving technique will be responsible for 70% of your fe improvements, unless you make a boattail van :)

Good Luck
Ryan

Sadly at the moment a Scangauge is out of my budget. Recently switched jobs, saving up for the clearcoat, etc...

I must admit, I am surprised.

rmay635703, I'm glad you're from around here so you'll understand the locations I mention in this post. I put coroplast under my van and tried neutral coasting as much as possible. Easier said than done. In the country I was doing steady speeds, but I'm still learning in-town how long it takes the van to slow down. It spends a LOT of time at 30mph when coasting I now know...

Before Christmas, I worked in Oshkosh. I would drive from just south of Fond du Lac to Oshkosh daily, taking Highway 45. Once a week for a month I did a "per trip" test, driving from the gas station, home, then work, then back to the station. I always go to the same station, same pump. I determined that a single average round trip cost $12.50, and at a 57-mile roundtrip, that's 11.76mpg at the fuel prices then.

Between today and yesterday, I put coroplast under my van going from the front bumper to the lower control arms, coasted in neutral whenever I could, and only took Highway 45 at 50mph instead of 55. It wasn't a direct "roundtrip test", but instead I drove home from the pump last night, went to work this morning, put the coroplast under my van, then drove up to Oshkosh and back, stopping at the pump on the way back. Even though I had to run my air conditioning the entire time to keep the windows from fogging up, I quickly punched in my calculator... 75.6 miles / 5.036 gallons... 15.008mpg!

Obviously I can't verify whether it's the neutral coasting in-town or the coroplast on Highway 45... but something is making a huge difference here!

Phone camera sucks, but here's a picture of the coroplast as installed under the van... going from the front bumper to halfway under the engine crossbar, with the corners under the lower control arms

http://img693.imageshack.us/img693/9388/i7wsvso9.jpg

So while there's still room for improvement, especially with how I had the a/c running throughout the majority of the trips.... I must admit, everyone's advice (especially rmay635703's) is really helping out here!

Glad to help, I've been there done that so to say and I've spent more than my far share of time going down 45, 40-55mph (I just try to stay going a little better when folks are tailgating in the 55mph sections)

Also having a painfully rock hard throttle position once you are cruising along is critical, especially if you don't have any guage. If you can very slowly move the pedal out going up gentle hills and very slowly move it in going down you will find your FE goes up even more, it hurts my leg though as the movements are minute. And on larger hills leave the pedal fixed in one position so you don't drop down gears.

I would estimate your improvement is pretty much in line with what happened with my dodge ram club cab. You will find the slower you go in overdrive the better your fe, also the more you coast the better. The coroplast underneith probably just sweetens the deal a bit.

Effectively what I've learned is that I almost never have enough distance to safely coast down (and it takes too long occasionally) I can't stress enough how much in town coasting and even off the highway coasting helps fuel economy. Heck my winter FE in town was between 8-11mpg before I started coasting, now I usually get at least 14mpg in town. Just make sure your in N when coasting or FE doesn't increase much, not sure why dodge has the engine race in gear but it does.

Once you log some full tanks using what you've learned so far we shall see what the fe ends up being. Oh and I would love to see a full airdam to the ground on one of our rigs, if you can find some rubberized stuff or tall plastic sheeting might be a good 2nd step. Results might motivate me to do the same :)

Also apparently our rigs love to scuff brakes, might be a good idea to check your brakes and rearend aren't scuffing or binding up, it appears my LH front brake is scuffing a bit and both my rears are either scuffing or the rearend is binding. Apparently a common problem on dodge. I checked the RH front a while ago suspicious but apparently it is the only one not stuck.

Cheers
Ryan

At work I have an '02 B150 with the 318, same as yours. I haven't made any mods because it's not mine, but I can see lots of places where I'd make mods:

Serious air dam up front. Unfortunately there's not a lot of room for sculpting it to slide the air to the side, but it'll help with the front suspension anyway. You may be able to add a grille block with improved air scooped up from below.

Fair in the rear bumper so it isn't a parachute at the back of the vehicle. It's a little thing but every little bit, right? And it's totally invisible once it's done; nobody'll ever guess you've made a change. Add a couple of drip holes for drainage.

The rear tires are in gigantic buckets just crying for wheel skirts. You could maybe add smoothy discs for the front wheels too. I'd also add wheel pants in front of the rear wheels to break the flow around them, and behind to close it in again smoothly.

You say you can't afford another set of wheels and tires, but you mentioned you're on snows right now? Snows don't last long; they're a softer compound, you're going to need tires regardless pretty soon. When that happens, go as skinny as you can.

I probably haven't told you anything you don't already know.

ahanix - congrats on some big results.

I read that type of claim a lot (particularly by owners of thirsty vehicles who don't have fuel economy instrumentation), and it never fails to irk me. I'm very glad you've proven yourself wrong!

Going from 11.8 to 15 mpg: the likelihood that the partial belly pan is worth a 27% MPG improvement that you've seen is pretty small. What you're seeing is mostly the result of driving technique.

Don't get me wrong: the mods help, and I'd encourage you to keep going. They all add up. But the biggest returns come from driving technique first -- unless you're willing to completely fair and boat tail that puppy!

This was a full size van, "oil crisis" era.

I'm assuming just from everyone else's experience that the neutral coasting made the majority of the difference, but I do know I am hearing less wind noise on the highway now, and never had an opportunity to coast on the highway.

I love tall gearing. 3.55 rear end means once I hit overdrive, my engine stays slow! Better yet, since work is right off Johnson Street [23], I can spend the vast majority of my drive in 4th gear (like everybody else, I cruise down 23 in town at 40mph)
40mph: 1000rpm [Unknown power]
50mph: 1400rpm [70hp / 265ft-lbf at crank]
75mph: 2000rpm [110hp / 275 ft-lbf at crank]

rmay, I'm still not figuring out the wavering you mentioned... what exactly is your technique? I know what you mean about how you can feel the minute changes...

Quick video of how I accelerate: http://www.youtube.com/watch?v=Mhu4VaJCK-w you can see that it spends a lot of time right at 2,000.

All this talk about how Dodge programmed the fuel injection to use more fuel in gear makes me wonder how effective a well-tuned Megasquirt system would be... so you could override the computer and manually control fuel....

You don't need a MS to get custom fuel maps. There are a few independent tuners out there who mess with the Dodge computers. 96 should be OBD II and able to be 'tuned'. I've never known anyone to tune for FE before, but I'm sure it could be done.

Who are they? And how many billion do I need to drop before they do it?

My guess is nobody in wisconsin.

Better picture of my coroplast job. No measuring, just random cutting.

Someone mentioned my radio antennae. Is there anywhere to get a replacement antennae that is very low-profile? I'd kinda like those "shark fin" ones, but I can't find one that isn't just decorative plastic. And I can't really do any "boattail" stuff because where I work requires I park in a parking garage. I'm already scraping my antennae going up


Got kinda sidetracked. Realized just how great I can get it to shine by colorsanding :) Now I'm hell-bent on figuring out what all I need for this restoration in spring

http://img693.imageshack.us/img693/3...5696223851.jpg

http://img248.imageshack.us/img248/4461/0208002357.jpg

Considering it's $5/can spraypaint, I'm impressed with how it'll shine. Makes me much more confident in my abilities to do the actual "PPG Shopline with an air compressor and clearcoating"

I don't think you read that here.

I'd investigate a partial grille block before worrying about your antenna.

You can make inserts that cover only the area that is actually OPEN on the grill.

Also, you can make a panel or two that directs the air from the grill directly to the radiator, it'll help make better use of what cooling capacity you do have.

Being a Dodge Automatic (I know, I've owned 13 Dodges 11 autos) DO NOT COVER that transmission cooler. It barely does it's job as it stands!

Ahanix

Mine does not have a separate transmission cooler, it just uses the lower part of the engine radiator. Can I block the grille from the back? And if so, where should I be doing -- the top grille half, bottom grille half, or bumper steps? I'd assume top half because it won't interfere with the transmission-end of the cooling.

Since I plan on doing all kinds of body work to the van before painting, I may as well remove the radio antennae and bondo over the hole it leaves behind -- I accidentally drilled through my CD player so the radio functionality doesn't work (and neither does the volume knob!).... I'd really like to find a functional "sharkfin" antennae to replace it.

Everyone is telling me to remove the roof rack, but I kinda like how it looks. Makes it look less "cargo-y". I don't believe it has AS MUCH of an impact as the really large roof racks people put on smaller cars... this is two bars going across the sides.

It'd be really nice if I had some kind of option for my windshield wipers. GMC was smart enough to recess theirs, but my Dodge has them sticking out.

Yes.

The upper half on a dodge and blocking inside is OK, however if your trips are under 20 miles and you have good temperature guages for the transmission and radiator just block the whole thing during winter months. Otherwise to block your grill especially on a dodge couple your grill block with an air dam that goes nearly to the ground, that will improve airflow through the grill and reduce air resistance under the van. It is critical that the transmission get enough airflow to cool

Antenna doesn't do much on a big rig like we drive.

Roof rack remove will have a slight MPG improvement, especially on the highway, much more worthwhile than antenna remove and even sweeter if you can figure a way of having it installable when needed as well as removable when not.

Minor issue, much more drag off your square rearend, non aero wheels and under the vehicle

Speaking of which, rear fender skirts and pizza oven wheel covers do have FE effects.

Good Luck
Ryan

Yeah but them shiney chrome rims :C
I've honestly never used the roof rack. I just like how it looks.

[Obviously I'm kinda uncommited to efficiency]

Ornamental roof racks?? Jeez. Ditch 'em! Or I won't respect you in the morning!

Flag on the play!

The fuel injection may be staying in "open loop" longer then it should.
Put that back to stock rated.

I'm mostly a GM and Toyota guy. On GM's swapping a 180 thermostat for a 195 almost always reduces the economy and makes drive-ability issues such as fowled plugs and plugged cats and causes CEL lights for o2 sensors. In the GM forums the post usualy start with " I failed my smog test. High HC reading.

On Toyota's they have a "jiggle valve" that allows for a small amount of bypass to preheat the radiator to prevent temp bounce as well as equalizing pressure so that the flow off the pump doesn't hold it closed. It also aids in bleeding air. 1/8 inch hole in the lip of the thermostat is a common shadtree trick to do the same.

Impressive gains with the changes you did. :thumbup:

^^ Agreed. Even though it's a PITA, swap a 195 back in there. I used to be a 180 person "gives more power" The hell it does! Truck is MUCH happier with a 195.

(00 Ram 5.9 Magnum, FYI) Found this on my buddies Dakota (5.2) as well as my Dad's 5.9. Turns out most stock specs are that way for a reason. Weird...

You guys are probably right.... once the thermostat opens it has a tendency to drop pretty low for up to ten minutes. If it's below 10°F out it can spend the entire drive just barely above the lowest 1/3-mark.... rather than halfway between 1/3 and C when normal.

Is there any way to determine when my engine is in "open loop" mode? Is there a certain trigger I can tap into?

A scanguage or OBDII reader can determine this. As for doing it yourself, best to just get an MPGguino assembled, they don't cost much and work well. It takes a computer to really determine what your OBDII is doing real time, can't really watch voltages.

Also on Dodge Open Loop is sometimes better than closed when the motor is cold, my truck is affected by temperatures dramatically, when cold my MPGs are 50% of when warm and when warm but not quite up to temp my FE floats about 25% lower than fully heated.

Bah, I want a nice clean look, MPGguino doesn't fit that... hobby boxes aren't my thing. I'd rather just buy a Scangauge in that situation.

I don't know the specific temperature ranges.
This is where my needle is on a 32°F day with the heater on.
It sits a little lower when it's 10°F or below

http://img109.imageshack.us/img109/6584/0222001747.jpg

As you know that doesn't mean much, The thermostats relative position from day to day is most important, if its lower on cold days you are likely running cold.

Also I think you need an altitude adjustment, the MPGguino is just a tool. Just as you don't drive around with a wrench holding your hood up or a oil pail stuck under the motor you also don't need to have the MPGguino continously mounted, you use it to learn and then put it away when not learning, it does afterall REMOVE in under a minute and is easily stowed anywhere you like. And obviously like a hammer you can use it to do many things or choose not to use it at all if you are ashamed of having it show.

Also you can build a nice purdy case for it if thats your flavor and the guino can come fully assembled ready to go as well.

All this said, I use a scanguage on mine continously and the way I have it mounted isn't pretty but practical since I move it between multple cars. Its up to you how professional the mounting and location is or set it up so it can be removed easily.

If you do find yourself buying a scanguage, remember, get it on ebay or from JCWhitney using one of their 20% off orders over $100 with free shipping. Don't pay too much and remember a scanguage 1 does most everything the 2 will do at a much better price

Cheers
Ryan

Oh really? Didn't even know they still sold ScanGauge I's. What "features" did the II add that may justify the price, if anyone happens to know?

I think I'll get a ScanGauge soon... but I'm still having trouble figuring out that thing with the throttle you mentioned earlier. Also, have you looked into adjusting the TV cable for earlier, softer shifts?

closed-loop monitor
I built one of these for my vx. You can change it to light for closed or open loop. I should try one on my van and see if it helps. I have a extended 15 passenger dodge 3500 with the 5.9L. The best thing for fuel economy is to park it.

No they don't sell them but they do show up for about $50 or less on ebay every couple of months.

Differences, Xguage & Fuel Cutoff detection I believe, along with being able to save a bunch of trips fuel economy info

The wiggle the fuel pedal thing is only going to have meaning if you have a scanguage and see what effect it has. For me it works best when the motor is cold, I rapidly wiggle it in and out 3 to 4 times a VERY Very small amount from idle then slide in to take off (my rpms only jump to maybe 1-1.2k while wiggling). My paticular truck takes off harder if I do this with less pedal, I am beginning to think it has something to do with my transmission as it likes to stay rather solidly stuck at low speeds for some reason. I also have found I can take off harder as compared to just sliding the pedal in around 20-30mph if I do that trick as well.

Cheers
Ryan

It can be sort of true though. You know I know how to drive eco and have for a long time. The F250 460V8 5sp pretty much delivered the same fe no matter what- empty, laden, headwind, tailwind. I think such vehicles normally tap into very little of their power and as such the throttle position doesn't have to change much for varying conditions, unlike our little low powered stuff.