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

[Domman56]

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

[RandomFact314]

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)

[ahanix1989]

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?

[rmay635703]

Originally Posted by RandomFact314

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)

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

[ahanix1989]

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

[ahanix1989]

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



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!

[rmay635703]

Originally Posted by ahanix1989

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'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...

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!

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

[elhigh]

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.

[MetroMPG]

ahanix - congrats on some big results.

Originally Posted by ahanix1989

"Driving variances" doesn't really apply, it's ALWAYS 11.75 to 11.83 mpg, no matter how I drive.

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!

Originally Posted by rmay635703

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

Originally Posted by 1989

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!

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!

[MetroMPG]

Originally Posted by ahanix1989

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

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