Bad fuel mileage 5.7 hemi

[SB89]

Been filling up with 87 octane for the first 775 miles or so. Filled up with 89 today for the first time and in the next 30 miles, definitely noticed an increase in mileage when cruising on the highway. This was my first tank using Fuelly so I’ll be monitoring this going forward. My cluster is telling me the first 800 miles is giving me 11.4 MPG which is just terrible, but a lot of day-to-day city driving and a lot of remote start warmups the last 2 month have definitely figured into that.

If I had to guess, on average I’m about 12-15 city and 18-21 highway through the first 800 miles. We’ll see if upping the octane helps. The weather warming up certainly will too.

 

[machz]

Been filling up with 87 octane for the first 775 miles or so. Filled up with 89 today for the first time and in the next 30 miles, definitely noticed an increase in mileage when cruising on the highway. This was my first tank using Fuelly so I’ll be monitoring this going forward. My cluster is telling me the first 800 miles is giving me 11.4 MPG which is just terrible, but a lot of day-to-day city driving and a lot of remote start warmups the last 2 month have definitely figured into that.

If I had to guess, on average I’m about 12-15 city and 18-21 highway through the first 800 miles. We’ll see if upping the octane helps. The weather warming up certainly will too.

The weather warming up will change your MPG so it will be difficult to monitor 89 octane. I don't use remote start often but my mileage is going up anyway because with the warm weather the truck doesn't need to stay in a cold start loop as long. Plus if you are in an area where winter fuel is used you will see an increase when they change over.

 

[Pribilof]

As stated earlier in the thread I live in the city (urban, not suburban) and the dash was showing 9.6 mpg for the first 1100 miles. I just did roughly 110 miles of highway driving and the dash is now at 11.8 mpg. Obviously once the truck gets rolling it gets great mileage for a 23% bump in lifetime MPG in only 110 miles.

 

[HKP7PSP]

Mine has been getting better almost every week. I'm at 3000 miles as of Monday, and into my 7th week of ownership. I'm pretty heavy on the throttle and can still eek out almost 15, and with calm driving up to 17 in my 60/40 highway/city commute.

 

[Creep0321]

Granted this is computer, and only my trip home from the dealership, but I’m happy.

 

[Jackham]

Be careful and do not log anything negative as the moderators will erase it and tell you it is is no relevant. God they are.

 

[edrclark]

Be careful and do not log anything negative as the moderators will erase it and tell you it is is no relevant. God they are.

Give it a rest, you posted a comment on a thread that offended a member who then reported to a moderator. That comment was deleted.

 

[MG99]

My first rig was a 77 K5 blazer, still have it actually. Warn hubs and an NP203 transfer case with part time conversion. 4wd always worked never had to worry about an actuator of some sort not doing what it was supposed to. I had a 95 Chevy extended cab, This was the last 4wd vehicle I owned that had a floor shifted manual t-case but still relied on an electric CAD to lock in the front wheels. My last 5 trucks have all been push button 4wd. Manual anything just isn't an option any more to make matters worse GM has actually done away with a low range transfer case on their lower trim 4wd models for 2019 you have to get a trail boss, LTZ or high country package just to get 4wd lo. Hopefully this isn't where everyone else is headed.

My father had a lifted ‘79 K5 (in the late 90’s). Three speed manual. It’s what I learned to drive stick on, and also learned about locking hubs and 4WD. Loved that thing. At that time everyone was buying 4cyl imports that sounded like bees buzzing by. So, instead my first car was a ‘68 LeMans (looked like a GTO, prev owner swapped front end and rear bumper). Had a crate motor, 4 spd Hurst and 411 Posi rear. I enjoyed doing burnouts in all 4 gears and setting off Honda alarms as I rumbled by. Good times.

Oh the point of all this is... Of the cars and trucks I’ve had or driven (6) only one got good gas mileage so I’m fine w/ my Ram doing 12-16mpg range.

 

[runamuck]

My father had a lifted ‘79 K5 (in the late 90’s). Three speed manual. It’s what I learned to drive stick on, and also learned about locking hubs and 4WD. Loved that thing. At that time everyone was buying 4cyl imports that sounded like bees buzzing by. So, instead my first car was a ‘68 LeMans (looked like a GTO, prev owner swapped front end and rear bumper). Had a crate motor, 4 spd Hurst and 411 Posi rear. I enjoyed doing burnouts in all 4 gears and setting off Honda alarms as I rumbled by. Good times.

Oh the point of all this is... Of the cars and trucks I’ve had or driven (6) only one got good gas mileage so I’m fine w/ my Ram doing 12-16mpg range.

I have a little over 4000 miles on mine now and I got 18 on two trips last month from DFW to the mountains of northern new mexico and back. cruise on 78. nice to see over 600 mile range after fill-up. my 2017 sierra 4x4 ccsb 5.3 with 3.42 rear end would only get 19-20 on same roads so the ram not too bad.

 

[Jackham]

Give it a rest, you posted a comment on a thread that offended a member who then reported to a moderator. That comment was deleted.

YES SIR pc SIR.

 

[19reb]

My Rebel gets around 13 mpg average according to the on board computer.

I've never been able to get more that 13 - 14 mpg out of a 5.7. No matter what it's in. They're just terribly inefficient engines until you modify for performance. Even after a dozen mods I was only able to muster 15 or so average and that was with 4.56 rear gear. Probably would have been around 17 or 18 with the proper 3.55 highway gear.

You can drive it on the highway and bring the average up, but as soon as you get back to the city or wherever, the mileage will just go back down to the usual.

One thing that will make the 5.7 drink is letting it sit and idle. A 5.7 will gulp down massive fuel while just sitting at an idle. Neither my 6.4 or my 6.2 did this. Every 5.7 I've ever owned(over a dozen) has done this.

 

[jerry]

I don't have etorque, but have 5.7 and 3.92. I drove this at a little over the speed limit and did city driving in Nashville,Tn and Kennesaw,Ga. as well as some driving in Orlando. I hit major headwind in south Georgia and started losing MPGs quickly. Decided to get behind a semi doing the same speed as I was using adaptive cruise control . Noticed immediately my cylinder deactivation came on pushing mpgs to upper 20s. The headwind was so bad that driving into it was to much to allow the MDS to come on. Etorque is supposed to help out with this but I only hear complaints about the bad gas milage. I"m wondering if anyone with etorque are getting above 20 mpg on long interstate trips.

 

[Kungfubhuda]

I don't have etorque, but have 5.7 and 3.92. I drove this at a little over the speed limit and did city driving in Nashville,Tn and Kennesaw,Ga. as well as some driving in Orlando. I hit major headwind in south Georgia and started losing MPGs quickly. Decided to get behind a semi doing the same speed as I was using adaptive cruise control . Noticed immediately my cylinder deactivation came on pushing mpgs to upper 20s. The headwind was so bad that driving into it was to much to allow the MDS to come on. Etorque is supposed to help out with this but I only hear complaints about the bad gas milage. I"m wondering if anyone with etorque are getting above 20 mpg on long interstate trips.

You get MDS to come on at speeds over the speed limit? I cannot get MDS going anything over 50 unless I'm going downhill.

 

[Neokane]

Why doesnt MdS activate at complete stops, and de-activate when you lift your foot off the brake?
Certainly we dont need all 8 cylinders for idle.

 

[Creep0321]

I’ve gotten MDS to stay on at up to 68 so far.... one trick I found that helps me is set cruise to 70, once stable click down 2x to 68 and it engages/activates.

 

[OuachitaAdventure]

Been filling up with 87 octane for the first 775 miles or so. Filled up with 89 today for the first time and in the next 30 miles, definitely noticed an increase in mileage when cruising on the highway. This was my first tank using Fuelly so I’ll be monitoring this going forward. My cluster is telling me the first 800 miles is giving me 11.4 MPG which is just terrible, but a lot of day-to-day city driving and a lot of remote start warmups the last 2 month have definitely figured into that.

If I had to guess, on average I’m about 12-15 city and 18-21 highway through the first 800 miles. We’ll see if upping the octane helps. The weather warming up certainly will too.

I have the same truck specs as you do. I think your mileage will improve once you get some miles on it. The remote starts will kill your mileage if you let it run for a while.

I've been impressed with my mileage so far. Did some mileage vids for city, highway, and interstate.

 

[Ortiz7983]

You get MDS to come on at speeds over the speed limit? I cannot get MDS going anything over 50 unless I'm going downhill.

MDS came on for me at 79 mph

 

[Chris]

Why doesnt MdS activate at complete stops, and de-activate when you lift your foot off the brake?
Certainly we dont need all 8 cylinders for idle.

MDS causes much higher than normal vibrations; the new trucks have added features specifically to assist in reducing the vibrations (such as shaker weights in the frame, which is why they claim to be able to utilize MDS more before the shaking becomes too violent), but the lower the RPM the worse the vibrations. Combine that with the minimal RPM of idling, and your truck would feel like it is misfiring and about to blow up at every stop sign.

 

[Dradin]

I wanted to add to this thread that my gas mileage to and from work has been decent at around 16 mpg (30 min drive with 20 min interstate). I have a bit of a lead foot so I am driving aggressively and getting this so I am impressed. With two 9+ hour road trips I have gotten 18.5 mpg going 80-85 mph on the interstate and with rarely using cruise control.

I buy my gas at Costco most times so I am putting premium (93 or 92 octane depending on which state) in it for reference. Costco consistently has the best gas prices where I am.

When I first took delivery of my truck (with only 3 miles on it) I did the break in period and drove extremely conservatively and got 23 mpg for my first 500 miles ( verified via hand calcs because I couldn't believe it). I couldn't stand being passed so I guess that I will never see this level of mpg ever again..... but boy is my truck fast.

See my signature for my build.

 

[Neokane]

MDS causes much higher than normal vibrations; the new trucks have added features specifically to assist in reducing the vibrations (such as shaker weights in the frame, which is why they claim to be able to utilize MDS more before the shaking becomes too violent), but the lower the RPM the worse the vibrations. Combine that with the minimal RPM of idling, and your truck would feel like it is misfiring and about to blow up at every stop sign.

Interesting...