Hi, i have a 4.7 L thats getting 13.3 mpg , this seems bad to me considering my 1996 ram with 5.9L got close to 20 mpg. I might get a newer truck and was woundering which motor of the 5.7/5.9 would be a better choice for decent gas mileage , by decent i mean 18mpg or better . Any feedback is appreciated.

thanks

 

how were you gettin 20 mpg on a 5.9 magnum

 

Yeah, My dads 5.9 sucked about as much as my current 5.7. Only difference is the 5.7 has more power stock than the 5.9 but neither are going to get you 18+

 

I think if you posted that you got 20 mpg out of a Ram with the 5.9 in it I'd have to close the thread down within half a day, LOL.

My '98 RCSB 5.9 4x4 got 11 mpg in over-all driving and I lived WAY out in the country at the time. Almost NO stop n go driving. I might, just might nip 13 on a trip IF I kept it around 65 mph.

I was in an '02 4.7 Sunday, riding shotgun on a trip across state for a golf outing and when we returned, it was just under 20 on the overhead... Pretty much bone stock 4x2.

As for my Hemi, you can't go by it, it's not only modded to the hilt, but weighs in at close to 7000 lbs., but it gets about 12.5 combo and can be just over 16 on trips if I stay at or near the 70 mph speed limit...

 

I figured it out that way when i got the truck 8 years ago it was around 20 mpg ...... I put 20 dallars in it to drive 150 km , gas was cheaper then also.... this 4.7L 5 speed short ram i have now gets 13.3 and i can see the difference big time from my 5.9.L ..... The big 360 would idle around it had so much power , not labouring at all , if i drive 120 km per /h on the highway it would suck it back . My calculations on the 5.9L might not have been spot on but like i said there is a noticable diff from the 4.7L and the 5.9L which was better for gas mileage.

Maybe i calculated the 4.7L wrong ...... yesterday I drove exactly 236 km and she used 41.7 liters of gas to do it ...i figured that to be 13.3 mpg andthis is what the overhead readout says ...funny thing is i just changed an 02 sensor and with the old sensor in it previously it woild read 15.9 to 16.4 ..... would one sensor make thAT much difference .

 

you cant just change one O2 sensor...you have to replace them all

 

^^ why can't you just change the one as the precat o2 is the one that meters/monitors your air/fuel mixture, the rear o2 just checks the Cat efficiency.

if you bought a cheaper 02 than factory it might be making the truck run rich, unhook the battery to reset everything then see how it works.

 

i owned a 5.9 extended cab 4x4 and worked at a dodge dealership as a mechanic for six years until they sold out and let me tell you if you got anywhere near 20 mpg with the one in your signature with a body lift and 33 inch tires then you should have never sold it cause you had the golden one!

the average for a extended cab 5.9 4x4 with no lift and stock tires which I believe were 31.5" was 11/14.

never changed out all the o2 sensors at my dealership and there is no tsb to the effect. vehicle came in with a failed one then the one indicated by side/bank by the code was the one got changed. an o2 sends a voltage to the pcm based on what it reads going past it and whatever any other o2 reads or sends has no bearing on it.

 

I have a 2005 5.7 with a 6 inch lift and 35 inch toy's and I get around 9.8 in city and 11.7 on the highway. That's why I made trade a friend for a cummins!!

 

5.7L 04 ram quad 4x4, w/shorty headers, magnaflow cat back, recent spark plug and oil change: avgerage combo city/highway display = 14 to 14.5mpg.