Hey df members.i have a 97 ram 5.2 and im getting about 10.4 mpg. How much better gas mileage can i get out of this? I looked in the tb and saw oil in the bottom. Im planning on replacing the plenum gasket with autozone one for now. BUT will i see a difference? And whats the mpg you get and you have any mods? what motor.
Thanks I really appreciate it
Brandon.

 

Is that city, highway, or combined mileage? Are you heavy on the go pedal, or do you drive like a grandpa? (Not this grandpa, mind you, but like a geezer.)

Get your plenum gasket from the dealer! If in fact the gasket is blown, your mileage should jump by 2MPG or better. Be sure it's not a failed PCV valve before you go through all of that bother -- that's a part you'll always want to get from the dealer. It's in the neighborhood of eight bucks at the dealer so it's not worth saving a few bucks to end up with a bad part from somewhere else.

If you're burning oil, the cat and upstream oxygen sensor will be next to go.

I've got a 5.9l and I'm normally seeing just shy of 13MPG city, but when I get to feeling frisky I can knock it down to 10MPG without half trying. My normal style is a bit faster than most but not really getting much deeper than 1/4 throttle around town -- doesn't take much to motivate the old truck. On the highway I see around 15MPG, usually with three or four adults in the cab and 100-300 pounds of additional weight in the bed.

All of my (few) modifications are listed in my garage -- with the exception of the 265 tires that are a step larger than stock and which must be costing me a bit of economy in city driving. Also beating me up on fuel economy is the weight of the headache rack, toolbox, and contents of the toolbox which are about that of another large adult.

10.4MPG is pretty lousy for the 318.

 

If you are not replacing the plate too, then you will want to grind the pan bolts shorter or get some shorter ones. And don't forget to use loctite on the threads.

 

ok thanks.
and ZMAN why do that?

 

Because part of the problem with the plenum is that the bolts(for the steel pan) are too long.