Bad fuel mileage 5.7 hemi

[riccnick]

3.92 with 8 speed loses 1-3 mpg vs 3.21

Who told you that?

I have a 3.21 truck with eTorque (but a 4x4) and I get 14-15 city and nowhere near 21.5 on the highway.

 

[silver billet]

Who told you that?

I have a 3.21 truck with eTorque (but a 4x4) and I get 14-15 city and nowhere near 21.5 on the highway.

This is only the computer of course, but converting that 9.7 = 24 mpg. Very happy with highway mileage, was a 3 hour trip pretty much all highway. Before the trip, I was at 11.5 l/100 km (20.4 mpg) and that is mostly rural and what I've been sitting at for about 3 weeks. I ran out of highway since I arrived at my destination, but it was still dropping and would have gone lower yet if I didn't have to stop.

My v6 jeep gc got about 9.1 l/100 (26 mpg) so comparing the two, this Ram is doing quite well.

I'm sure the the MDS plays a huge part in this, it works quite well. I notice it kicking in already at 30 km/h during light acceleration, and it stays active even while continuing to speed up at that pace.

Definitely more than I was hoping for, figured if I hit near 18 mpg highway I would be doing great.

 

[sergetexan]

Who told you that?

I have a 3.21 truck with eTorque (but a 4x4) and I get 14-15 city and nowhere near 21.5 on the highway.

Like I said this was best so far with 4,000 miles, usually see around 17 on Houston highways, this was a moderate 65-70 mpg drive over flat terrain. Reading all the threads the 3.21’s are the better performers being reported, especially on highways where can stay under 2000 rpms at higher speeds than th 3.92.

 

[SD Rebel]

The best mileage is from 2WD 3.21 with street 18" tires. The lowest mileage is 4WD 3.92 Rebels w/ 33" tires.

The problem is the EPA rating is based on the former but FCA still applied it to the latter. Which is wrong honestly. There is no way a Rebel w/ 33" tires & 3.92 axle is going to come close to 22 mpg highway. The city 17 mpg rating is downright insulting, lol.

The one thing Chevy got right with their new Silverado is that they actually separated their Trail Boss mpg ratings from normal Silverados. They know off-road A/T tires is going to effect mpg. But of course, as consumers we should know better. When I purchased my Rebel, I knew what I was getting into and 22 mpg highway wasn't it. I'll be lucky to get the city rated 17 mpg hypermilling on the highway.

 

[19longthorn]

Took the camper to Yellowstone last week and quickly realized that its cheaper to fly from now in with the new truck. I was also losing speed on a 5% grade. 21ft mini lite at about 5k lbs. Seems odd considering the tick is rated to pull 11.5k lbs.

 

[Willwork4truck]

Took the camper to Yellowstone last week and quickly realized that its cheaper to fly from now in with the new truck. I was also losing speed on a 5% grade. 21ft mini lite at about 5k lbs. Seems odd considering the tick is rated to pull 11.5k lbs.

That shouldn't happen, not with that weight.

 

[RamGuy32]

That shouldn't happen, not with that weight.

It will suck gas at 75mph! Shouldn’t be towing that fast and it would certainly do better even at 65.

 

[rrbhokies]

225 miles on the truck and only averaging 8.6 MPG. Live in the suburbs, commute to/from commuter lot about 8 miles each way. Plenty of stop lights. But it's not the "City". It is a suburb area and you can occassionally cruise between 45 and 55 on long stretches. I certainly wasn't expecting 15mpg like the sticker says, but 8.6? Sure seems awful low. The same V8 Hemi in my Charger was getting almost 17mpg with the same routine, and with that car, I was always driving in Sport Mode and taking off like a rocket. With the truck, I pamper the s**t out of it, and getting half the gas mileage? Sure as heck hope this is the "breakin" mileage and it improves substantially. I was banking on 11 or 12mpg but don't see this truck every getting close to that.

 

[SD Rebel]

225 miles on the truck and only averaging 8.6 MPG. Live in the suburbs, commute to/from commuter lot about 8 miles each way. Plenty of stop lights. But it's not the "City". It is a suburb area and you can occassionally cruise between 45 and 55 on long stretches. I certainly wasn't expecting 15mpg like the sticker says, but 8.6? Sure seems awful low. The same V8 Hemi in my Charger was getting almost 17mpg with the same routine, and with that car, I was always driving in Sport Mode and taking off like a rocket. With the truck, I pamper the s**t out of it, and getting half the gas mileage? Sure as heck hope this is the "breakin" mileage and it improves substantially. I was banking on 11 or 12mpg but don't see this truck every getting close to that.

It should improve. Hard city driving, including lots of stop light idling and not light on the throttle I can usually hit from 9.5-12 mpg in that scenario. Do a trip reset on either A or B trip computer and keep track again for another day and see if it improves.

 

[Willwork4truck]

I missed that he was towing at 75, my point was that he shouldn't be losing speed while climbing, regardless of mpg’s. Id think whichever gears the 8 spd and hemi could at least keep pace, though not 75.

 

[Jus Cruisin]

Scrolled down while checking tire pressures and then down to miles per gallon which I haven't reset in a while. Lie-O-Meter showing 20.4

 

[19longthorn]

Yeah, that image showed 75 as we were in South Dakota with 80mph speed limit. But through Minnesota and Wisconsin doing 65-70 got home with 5.4mpg on the clock. Same type of driving with my 14 Ram Sport got me 8mpg with same camper and never had my foot to the floor in the 3 years of towing with it. I averaged 16 daily commute with the 14 and now 13 babying the 19. Something has definitely changed. Trailer tires are rated to 87 so not really sure why I shouldn't tow at 75....

 

[Zeronet]

Yeah, that image showed 75 as we were in South Dakota with 80mph speed limit. But through Minnesota and Wisconsin doing 65-70 got home with 5.4mpg on the clock. Same type of driving with my 14 Ram Sport got me 8mpg with same camper and never had my foot to the floor in the 3 years of towing with it. I averaged 16 daily commute with the 14 and now 13 babying the 19. Something has definitely changed. Trailer tires are rated to 87 so not really sure why I shouldn't tow at 75....

Towing 75mph with cruise control engaged in the hills/mountains is probably a bad formula for mileage.

Not sure about losing speed on a 5% grade doing 75. I never tow at that speed. 65 for me. If you’re talking about losing speed with cruise set at 65 towing 5000 with tow/haul engaged, yeh I’d say that’s not normal. You might lose a few mph before it downshifts and gets back to your set speed. Couldn’t see if you had tow/haul on in your screen shot, that should help maintain speed in the hills.

 

[RamGuy32]

Yeah, that image showed 75 as we were in South Dakota with 80mph speed limit. But through Minnesota and Wisconsin doing 65-70 got home with 5.4mpg on the clock. Same type of driving with my 14 Ram Sport got me 8mpg with same camper and never had my foot to the floor in the 3 years of towing with it. I averaged 16 daily commute with the 14 and now 13 babying the 19. Something has definitely changed. Trailer tires are rated to 87 so not really sure why I shouldn't tow at 75....

It’s inefficient. Most motors aren’t as efficient at that speed and then there’s the safety aspect. When towing it’s just going to exponentiate that inefficiency.

 

[Jus Cruisin]

Back in May when I towed from Florida to Michigan I looked at the mpg lie-o-meter and it was showing 9.8, if I remember, somewhere in Ohio. I was running 65-70 as much as possible and used tow/haul most of the time once I was through south Georgia. This is what I was dragging.... maybe 7000-7500 lbs total. A 3500ish trailer and 3500ish car.

 

[brotharon]

Thanks to all of you for making me feel a ton better about my truck! Not that I felt bad at all about it...it is a truck after all so that is good. I was just watching the MPG and noticing that I am getting about 14.9 MPG on the first tank of gas since buying my 4x4 Rebel. It would appear that is pretty good since all I do is city driving in South Houston. I would find it strange that there is such a variance in the reported MPG on these vehicles, but after seeing the MPG that my wife can get out of a vehicle nothing really surprises me any longer. Seriously, she used to have a commute that was 18 miles each way, 12 of which was freeway (60mph), rarely any traffic, 2007 Honda Civic LX ( I could get it to return nearly 40mpg) she had it sitting right at a tidy 13.5 mpg...so while there is certainly some difference between the different builds and configurations of the vehicles, there is no way to account for the piece of equipment that is placed between the steering wheel and the seat at the time of delivery.

 

[Raylan GIvens]

Some of these numbers are very surprising, and probably extremely disappointing to many. What I have noticed is these vehicles are very sensitive to certain inputs that cause fuel mileage to drop significantly and you need to adjust your driving style to see numbers closer to the sticker numbers. I I have had other vehicles that would return the same results no matter how I drove them, my 2009 Jeep Wrangler for an example didn't seem to care how I drove it. My truck with 3.92 and eTorque started at 16.5 and all following tanks were 17-19.5 depending on how much time I spend sitting in traffic. Today I checked with almost 4k miles and the current tank at halfway is 16.1 (worst I have observed), which I attribute to sitting in traffic with the AC going more than normal

The first thing to consider is Ram probably tested a truck configured with certain combinations that their internal testing had already shown would return the highest EPA numbers. So your truck with, ram box, sunroof, off road group, level 2, etc. is going to take a hit. I am sure the tires on the Rebel and ORG drop you a MPG alone, and then add it extra weight and a small lift in the Rebel and you have further reduced it. If you have 3.92 you are going to take a significant drop in MPG just from running higher RPMs.

The next thing to look at is your RPMs in certain conditions. I have noticed that sometimes driving 45 MPH I am getting 15 MPG on the dash, but if I apply the accelerator to get to 49 MPH i can get the transmission to shift and get 20 MPG. On the highway with 3.92 gearing anything above 70 MPH and my fuel economy drops. Also the poster above mentioned sometimes it is the operator that is the issue. I think my wife drives in circles all day and leaves her van running between stops because she only manages 19 MPG, and I get 22-23 every time I drive it and I have the skinny pedal to the floor the entire time to try to get that thing up to speed.

 

[ForTehNguyen]

is everyone using the mpg screen where it shows the current instantaneous mpg on the upper right corner. Have that up and try to make it a game to figure out the best throttle positions for your speed. You just gotta learn the sweetspots and really feel the pedal out.

 

[JJRamTX]

Scrolled down while checking tire pressures and then down to miles per gallon which I haven't reset in a while. Lie-O-Meter showing 20.4

I think we have the best comparible trucks for the difference between the 3.21 and the 3.92. My Lie-O-Meter shows about 17.9-18.1 I am sitting at 20,300 miles now so I think the drivetrain is broken in.

 

[rrbhokies]

The next thing to look at is your RPMs in certain conditions. I have noticed that sometimes driving 45 MPH I am getting 15 MPG on the dash, but if I apply the accelerator to get to 49 MPH i can get the transmission to shift and get 20 MPG. On the highway with 3.92 gearing anything above 70 MPH and my fuel economy drops. Also the poster above mentioned sometimes it is the operator that is the issue. I think my wife drives in circles all day and leaves her van running between stops because she only manages 19 MPG, and I get 22-23 every time I drive it and I have the skinny pedal to the floor the entire time to try to get that thing up to speed.

What do you mean by getting the transmission to shift? You mean from like 7th to 8th gear? My truck is in 8th gear at 30mph. Yet on my Pacifica you have to be almost 50mph to reach 8th gear. Heck, in my Charger, it wouldn't go into 8th gear until I hit nearly 60mph. So while I was thinking that maybe it's good that the truck is reaching 8th gear so quickly it would help save me fuel. But now that I think about it, maybe that isn't right? Maybe it's shifting too quickly to 8th gear and trying too hard which is causing the engine to feel like it's hesitating and jerking me back and forth, and may account for the dismal 8.6 mpg I'm getting. I mean, I don't accelerate quickly, and I even try to take my foot off the brake and coast as much as possible. And I don't brake hard. But no matter how gently I try to coax the truck, the mileage has never shown above 10 mpg and currently sits at 8.6. So what is the verdict? At what speed should the transmission shift into 8th gear while driving? Oh, and by the way, if there is an ECO mode, I've NEVER seen the ECO light go on in my truck, so I have no idea if that's a bad thing either.