Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post - How to improve Dodge Ram Van from 12mpg? [Belly pans?]

ahanix1989 · 02-06-2010, 02:43 AM

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?

02-06-2010, 02:43 AM	#1 (permalink)
ahanix1989 EcoModding Lurker Join Date: Feb 2010 Location: Wisconsin Posts: 13 Thanks: 0 Thanked 0 Times in 0 Posts	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?