V8 Ram Saving Gas

[DJeXeCute]

I have a 1998 Dodge ram 1500 rwd 5.2L 318 V8 Stroked to 402cui, poly heads, ported valves, aluminum intake, larger throttle body, long tube headers with highflow cats 3 1/2" pipes with dual 3 chamber mufflers to keep is livable sound wise(I forget what kind they are), Ecu is reprogrammed to shift at lower rpms and to lock into gear from 1000 to 1200 rpm for the most part, Axle is a Dana 60 with 3.23 gears and a detroit locker for better traction on and offroad. I average about 17-18mpg the way it's all set up which is allot better than most other rams like mine get but I'm still looking for a way to get better city mileage. The trans refuses to stay in gear while going up hills even though its got more than enough power to idle up them so I think I might try another shop and see if I can have them set it up to stay locked. My other mechanic says it's not possible to completely disable that but we'll see. Oh did I mention 47k Original Miles, it's been in the family since new and only driven by my late grandfather and me this past year.

What do you guys think I could do from here to get more out of it? I'm thinking custom fabbing a Tonneau cover for the bed since I have a diamond plate toolbox and bed rails and want to keep it all intact. Other then that I think I'm at the end of the line as far as gas mileage gains.

[cRiPpLe_rOoStEr]

A tonneau usually improves the mileage with a comparatively low cost. Go for it at least as a starting point.

[Gealii]

Tonneau is a good start
Smooth wheel covers would be a good idea
Partial wheel skirts as dodges seem to have large wheel wells

Never think your at the end as there is always something you can do

[UltArc]

Kammback, instead of a flat cover. Closed rear wheel wells. Belly pan, tire spats.

When you reach your max...you will find a new mod to try

[mcrews]

Gotta have a scangauge. See all the reasons in the first link in my signature.

[mikeyjd]

Manual transfer swap ^

[JRMichler]

Lots of stuff you can do. Everything listed so far, plus:

Grille block
Tire pressure
DWL
DWB
Manual transmission
Kill switch

[jamesqf]

Park it and buy a Honda CRX.

[justme1969]

Search mega viper transmission. for about 2k never complain about the trans again and iit shifts so fast and locks up quickly so it does save mpg and power v/s splash box 518 tranny stock.
Other than this the Dodge Magnum series was never ment for economy.
It would go toe to toe with ford and chevy big blocks for most things back then but used same amount of energy.
I really LOVE my Dakota R/T but cant afford to roll it to work every day, so it sits till I need to tow something or shut up some smart butt kid.

A mega viper is a must for turbo /supercharged and Nitro 360 magnum fun.