I have a '98 Ram 1500 4X4 with the 5.9L engine and automatic trans. I was pulling only 10mpg over the winter and I kept getting a code for the oxygen sensor behind that cat. Well I replaced that and installed new plugs as a few were getting crappy with it pumping out too much gas with bad info from the one o2 sensor. It doesn't seem to be much different then it was as it's still drinking just as fast as I can pump it in. What more can I do to pull better milage out of this. I would think I should at least be pulling 15 - 17mpg instead of the 10mpg that I'm currently getting. When I purchased the truck a year ago it did great, but I never checked at that time to see what it was pulling, I just could tell a big difference over time, and at that point is when I checked it. I don't want to spend arm and a leg, nor can I afford to, so what can be done or what things should I be looking at? I LOVE me truck and really don't want to park it because of the gas prices and mpg that it's currently getting. I hate driving small cars such as my wifes because I'm a truck driver and the biggger the better. I need to be up and not have my *** dragging on the pavement below me. Maybe a chip or something too, but again I need it to be as cheap as possible. Please help if you can.

 

1. Seafoam and/or MCCC
2. Full tune-up
3. Winter front -- Winter gas does cause less mileage plus idle time plus longer warm-up time
4. Tire pressure
5. Free exhaust
6. Tuner
7. Change ALL fluids in driveline
8. Plenum repair
9. Live with it, or
10. Sell it

 

Do you mean 15-17 mpg in town or highway?

That's what you would ideally be getting on the highway, not in town.

If you're pulling 10 mpg on the highway, I would suggest following the list that Ramman18 posted. Its a good start. If you're pulling 10 mpg in town, that's not bad at all for winter.

I am one of the lucky ones so far... no plenum repair needed yet (checked it when I installed my Fastman TB). I got 9-10 mpg during the winter in town, and I have a lead foot. Now with temps above zero and a slight increase in my tire pressure, I'm pulling into the 10-11 mpg range. Once it warms up even more (will be my first summer with the beast), I hope to pull it above that.

Speaking of this stuff, I still need to do a tune-up myself...

95% of my driving is in town or short sprints on the interstate to different places in town, so I never expected great MPGs. You have to realize that these are big, heavy, not-very-aerodynamic pickups with big V8s. Large + Lots of Weight + Not-an-airplane + powerful engine = bad MPG.

EDIT: That last statement was just concerning gas engines, not diesels BTW.

 

What mileage did you think a big ole 4x4 was going to get? You know you could put a Neon in your bed and still get about 5-7 mpg?

My best ever was 18 my average was 16.4. Lost one 1 mpg during the winter. I have a 2 wheel drive and drive 50-55 on a 98% highway, 30 mile trip both ways. Think about that, then think about what you will get.

Here's how you do it I have a ____, I drive ?% highway, I drive ____ mph.

 

My 01 Ram 4X4 got 10.2 this winter on average. That was with me driving it sometimes in 4X4 due to the weather and using a heavier foot. I drive 32 miles each way to and from work, about 25 miles of which is highway driving. I always drove about 5 mph over the speed limit. Hwy = 70.

Once the weather warmed up over 30, and fuel prices started the wife to really scream, a replaced my lead foot with a lighter one. I also drove around 62 in the 65 zones and at the city speed limit for 40 mph zones and less. For my last tank of gas I averaged 12.4 MPG with NO changes to the truck. I didn't even check the tire pressures.

I plan on doing another tune-up later this spring, installing my 180 thermostat, and airing my tires a little higher. All of these things and following what I did above might get me to 13, but I am not holding my breath.

I am a truck man also, I've only owned 2 cars (total of 3 years), 1 jeep CJ-5 (about 4 months), and 4 trucks since 1978 so I hear you when you say that you're a truck man. However, I did buy a neat 1994 Chrysler Lebaron convertible for my daily driver and it gets over 28. The cars fun to drive and in really good shape so I can live with not using my Ram as my DD.

 

I can get 20 mpg...


on a steep decline in neutral going about 80 MPH

 

lol...by doing all of those repairs, you could expect a little better mpg, but you must understand that these trucks were not made for mpg, they were made when gas was cheap, and horsepower and strength were what people wanted.

 

I have a 5.2 in a 99 quad 4x4 and I get 14 around town and 16 to 17 hwy. I have no major mods other than I just replaced my tranny (bumped me up from 13) a k&N air cleaner all synthetic fluids and that helped more than anything when I changed out to syn. I am running stock size tires with no lift. The biggest thing I see you need to make sure it is running right if you are throwing codes (especially for oxygen sensors it will run rich to compensate and kill your milleage.

 

I just saw in another post you made you have 265's on your truck if you have not recallabrated your speedo for the new size tires you are not getting a accurate reading on your milleage anyway.

 

I get 10-11 city all year round. I just bought new tires and had to go from 285's down to 265's. I used the hypertech and a gps to reset my speedo, I haven't gone through a tank yet to check gas mileage, but my guess would be 10-11 mpg, LOL