1999 Dodge Ram 1500 5.9 ..fuel milesage?

I have never owned a 4x4 truck before but I had to purchase because I take care of an elderly man that lives on top of a mountain and I have to have a 4 wheel drive to get there in the winter months. I recently took the truck on my first long trip 5 1/2 hour drive and on route 80 in Pa. I set my cruise control and keep my speed at the posted speed limit of 70 and in some places 65. I had filled up on Bloomsburg and drove to Pittsburgh and when I stopped to fill up I checked the mileage and I got 13 MPG... is this all I am going to get? I was hoping for 15-16 but maybe a 5.9 gas engine isn't efficient enough? or maybe if I drove at 55 to maybe 60 MPH...? but I am sure I would have pissed off a lot of other drivers so I didn't want to do that.
If anyone has a suggestion on somehow making an improvement, let me know. Thank you!

Driving at 70 mph that's about all that you're gonna get with a stock truck.

The best I ever got with that era Ram 1500 4wd with a 5.9 V8 was 14 mpg on a good day, but usually it was 13 mpg.

It's still better than the 8-10 mpg that I get with my 99 Ram 2500 V10 truck.

This subject gets kicked around every so often. Member Grizzly says to cut the catalytic converter out, and has figured out a way to trick the computer into thinking it's still there. I haven't done it yet, but it's on my agenda. Anyway, check out the thread below.

https://board.moparts.org/ubbthreads/ubbthreads.php/topics/2116622/1.html

Flyin' Ryan SCT customers report ~17 mpg in a 2wd Dakota 5.9 with his 'stock engine tune'. Plus about 35ft lbs of torque increase across the RPM band (the power increase is dyno proven on a few different trucks). You could consider a re-program but don't expect the same exact mileage. 4x4 vs 2wd and the 1500 is probably 1000-1500 lbs heavier.

The other thing you can do is a tune up to ensure everything is healthy. Check your plenum gasket, replace your plugs, wires, cap and rotor.

Yeah, 13 is good. stop and go is really bad tho...

My truck has seen 14 a time or two, but 13 is it.

55 mph might see a 14.5 mpg...

Do you have a link to these guys?
How much will it cost me to get 4 mpg better mileage and 35ft lbs torque? The 5.9 will be going into a hot rod, probably 1,000 lbs lighter then a last gen Dakota. Gene

Here's his website.

http://www.frptuning.com



He can send you a tune for a bone stock engine, and he can write you a custom tune for a modified engine from "just an intake and headers" to a fully built stroker with a big nasty cam, boost, nitrous, etc.

Fuel economy is a strange thing. Yes, this era of Dodge trucks are HORRIBLE on gas, nevermind the 4WD and 5.9 engine!

70 mph doesn't help either.

But here's a curious observation I have made- I currently have a 1996 GMC Suburban 4x4 5.7 automatic. I get 15-17 everyday with it commuting to work (which is spot-on for the EPA on this truck). I also had a 1995 Yukon 4x4 5.7 automatic- virtually identical trucks other than Vortec/no Vortec and about 12" of length. It got 19.7 in daily commuting! Go figure! LOL!

If it makes you feel any better, my 97 Dakota 2WD V6 got 17-18 mpg on my daily commute.

Took a 3000 mile round trip in my buddy's 97 ram a few years ago. His was a 1500, 4x4, extended cab, 5.2/auto. We were picking up something for me so I was footing the fuel bill. 75mph got us 13mpg. 55mph brought us up to 18mpg. That's about a 40% improvement. The rest of the trip the speedo wasn't allowed over 55. This testing was done when we were driving through the flat lands with the cruise set.

I would imagine the 5.9 to be a little worse, especially if yours has had the death flash that knocks a bunch of timing out of the calibration.

My prior truck, a 2001 2500 standard cab 4x4 5.9 gas/5 speed 4:10 truck, would manage to pull 12-13 mpg if kept around 65-70. Beyond that, it plummeted: 80 would put me in the high 10's. All this was driving in the north east, not flatlands like Kansas.

I have found a couple mpg is pretty easy to get with any number of tricks, getting big gains is hard even combining everything I know. A couple of the best improvements come from putting in ford yellow fuel injectors, slotting and advancing the crank sensor. Next up thin oil helps, long tube headers with a high flow exhaust. Hughes airgap intake (although this costs you noticable low end TQ)helps mpg but I would not combine it with 3.55 gears and typical 4x4 size tires or anytowing. Skinny tires. No lower than 3.55 gears, the deeper they are the worse MPG, the magnum engines deliver the best MPG at low RPM (1400-1800) and lugging them pretty good. A short duration high lift cam helps. Thin head gaskets help bump the compression up and that helps also, I like to buy one mr gasket MLS head gasket seperate the layers and use one outer layer of the gasket for each side, it is the equivelant of milling about .040 off your heads.

Certain mods are not worth it just for MPG increase but other side benifits may make it worth while any how. The SCT with the custom tune is gonna be very expensive but should help MPG a lot as well as give you more power, same thing if you pay someone to swap in the thin head gaskets or if you buy brand new injectors(I usually get a set at the JY for about $50 so it can be very cost effective)

No need for custom tuning unless he gets into heads and cam swaps. Ryan has 'canned' tunes for bone stock and mild bolt on trucks (M1/airgap, headers, tb, etc). And costs less than the Airgap intake you just reccomrnded.

Dave,what are the ford yellow injectors original application?What are the differences to the oem Mopar and benefits...spray pattern?
Thanks~Ron

I'll let Dave answer about the yellow top ones. I'm running it's blue top in mine. Factory rated by ford at a few lbs/hr higher, but dodge runs a higher fuel pressure so they're about the same. Since I have custom SCT tune though, the pulse width was tuned to precisely what I need for 15.7:1 at cruise and 12.5:1 at WOT; which is a much higher pulse width than stock due to my Edelbrock heads and cam.

The benefit to me was that these ford injectors have a 4-hole spray pattern. I couldn't answer to whether they're better or not because I changed a lot at once when these went on, so I can't comment on improved economy or idle quality, throttle response, etc. I put them on because the price was right and I figured they wouldn't be any worse than the stock injectors

The yellow ones flow about the same but have a much better spray pattern. They came on most 4.6 and 5.4 cars and trucks. If you need to order from autozone or something tell em it is a 97 F150 with a 4.6.

3000 miles at 55mph? How many weeks did that take?

I would helped with the fuel bill and drove 65-70, 55...

3,000 miles divided by 55 mph = 54.5 hours and used 166 gal of gas.
3,000 miles divided by 75 mph = 40 hours and used 230 gal of gas.
Saving 64 gal of gas, or 14 1/2 hours of driving? If this was done when the price of gas was $4/gal, that was a $256 savings! Over $17/hour savings. Gene

nice, don't forget the three extra gas stops for the 64 gal of gas.

We made the whole trip in 64 hours, including pickup time and time at the border. On the way back when we were pulling a trailer, if we were going much over 55, any little speed bump or rolling hill and that stupid transmission was constantly shifting in/out of overdrive.

My 96 got 13mpg, cat converter went out, swapped in a high flow and went up to 15. That was 200k mile truck too.