New Hemi owner

[dmcent63]

I have a ‘16 express rolling on stock 20”s with 3.21s. I used to see 17mpg when it was new. I’m always less than 14mpg now. The MDS rarely kicks in.

 

[beepster]

What is MDS?

 

[John KIOhio]

1st 2014 6.4 3500 had 410's 10 city /17 ish higway, sometimes up to 19 ish down in the flat states like Florida and lower Georgia. 2016 6.4 3500 Mega Cab had 373's 10 / 16 ish Highway. My new 2020 6.4 3500 410's (ordered this truck ) 8 spd tranny. 11-12 city and 16-17 ish highway. The new 2020 does not shift all the time like my 16 did on the highway, it never knew which gear was right. Many times I shut the ECO off or put it in Tow Haul on the 16. I hated that about the 16.

 

[John KIOhio]

What is MDS?

ECO mode. Stops fueling 4 of the cylinders. It is off when the truck is in tow/haul mode or if you manually put the truck in 6th gear with the +/- button. If you leave it in 6, it will still use all the gears but that is what shut MDS off on my 16. I would think it would work the same with 8 spd.

 

[Chance Boy]

I was told by another owner, that every 5,000 miles your mileage will improve and it did. Currently at 12K on my 202 1500 Limited and get around 20.5 at 70 ish highway. The other guy was at22-23. I’ll just wait to see.

 

[TomB 1269]

I have 2019 classic with 5.7 Hemi, 3.21 gears, and stock 17in tire/rim combo. Somethings I had to get used to besides just the knob for shifting.
1. The truck has lag at highway speed when in ECO mode (i.e. MDS activated) as it has to re-engage the 4 cylinders. In doing so it will also tend to downshift as you are giving in more throttle. Looking it in 8th gear with steering controls substantially decrease any lag.
2. When topping out a hill if I back of the throttle and she downshift on the way up she will hold the lower gear until I give her a little more throttle and maintain pressure on the pedal.
3. At 70 she is only turning 1600 - 1700 rpm, at just under 80 shes at at or just under 2000 rpm.
4. The HP8 trany in these are very smart and can downshift / upshift with respect to your driving style, road conditions i.e. up and down hill vs flats, and the payload / drag on the truck. It will downshift to provide engine braking and hold that gear. If you re-apply brakes with more pressure it will downshift another gear and hold it as well. It will not tend to hunt for gears pulling up hill. It tends to proactively gear down going uphill in a stepped manner verse large gear jumps and their associated high RPM jumps. Even in cruise control it will not wait to gear down and cause the transmission to drop 2 gears and tach 4000+ RPMs in one shot. On the reverse side it does not have to shift sequentially. Therefore when you floor it at 40-50 mph cruising it does not have to shift thru 7,6,5, etc. to get to 3 or 4 gear. It will come out of 8th gear and go right to 4th smoothly (as your A55 gets slammed back in the seat) by the Hemi.
5. The HP8 actively uses engine braking at slow speeds around town in stop sign to stop sign driving, particularly when under 35mph. I routinely feel the engine applying braking when rolling up to a the multiple stop signs in my neighborhood.

It does a have a different feel compared to older trucks. I come from a 2005 F150 FX4 Supercrew. The tech and response from the engine and transmission are substantially different and will take a little getting used too, especially if you are a seat of the pants drive like myself and can feel every bump, vibration and the slightest loss of traction thru the seat of your pants.

But after 18 months and 13000 miles I can say I am very happy with it and the way it drives.

As for gas mileage:
Straight in town and Fire Calls - between 10-12 mpg depending on amount of idling or the numbers of urgent calls (i.e. letting the engine whistle dixie AKA 5000+ RPM hits)
Mixed Town, Fire calls, and short highway 12-15 mpg.
Straight interstate Albany NY - Bradley Airport in CT - 80 mph & 17.5 - 19 mpg
Back highway - I.e. Albany NY, Vermont to northern NH to upper north west Maine (think Canada border) (hills, etc.) 19.9 mpg

FYI - these are MPGs from truck dash, actual hand calculations tend to run 1/2 MPG less.

The only thing I'd like to change is the rims to an 8 inch wide so that we can run 285/65-17. The factory 7in wide is not recommended for running a 285/65. The 285/65 provide about 1in more tire width and the same overall diameter. This would give it a little more in the handling dept as well as the launch traction. As it likes to light them tires up.

Final, thing which you will find a nice feature, but have to get used to is the BDL effect in 4Hi. The truck acts like it has lockers front and rear in 4HI. I am one that like to use 4LO for heavy off road, of brush and small tree stump pulling around my yard. However, the RAM drops the BDL (Brake Lock Differential) effect in 4LO and you spintires much easier as they are open differentials.

 

[RJM1269]

I'm getting around 18-19 in town but on highway 23-24 mpg I have 3.92 gears and at 70 rpm is just over 2000. The hwy mpg is with cruise set at 75 mph, Mine has 32 gallon tank which makes it nice on long trips, usually can go 730 miles before low fuel light comes on.

 

[Six8888]

I have a 2020 warlock with a Hemi, I was wondering if anyone could tell me if this is normal for this truck.

for starters this truck gets horrible gas mileage, like 12 mpg on a good day. While driving on the high way the truck has a hard time maintaining highway speed I really have to put my foot into it when there is any kind of incline. I’ve also noticed that when I take my foot off the gas the truck acts like I’m pressing the brakes, and this is going down hill with no extra weight onboard. I know truck is heavy, but it seems like it should move more freely. Thanks I’m advance for your input.

Release the parking brake

 

[Six8888]

 

[ParamG]

You should get about 17 mpg that's the best my 2019 hemi got on 17 inch wheels little worse on 20s

If your getting around 430 to 460 miles a tank its fine


Also check the parking break lol

 

[ParamG]

I'm getting around 18-19 in town but on highway 23-24 mpg I have 3.92 gears and at 70 rpm is just over 2000. The hwy mpg is with cruise set at 75 mph, Mine has 32 gallon tank which makes it nice on long trips, usually can go 730 miles before low fuel light comes on.

I dunno how you got that much miles my tank would go about 700 to 750km on 80 percent highway commute which is 430 to 460 miles

 

[Longhorn1500]

2014 1500 with 3.92 gears stock 20 inch wheels/tires about 43,000 miles, I get between 10 and 11 mpg.

Oh yeah, that's pulling my 9,000 pound Airstream trailer! I always turn off MDS by manually shifting (to 8, 7, 6, or 5 depending on situation).

 

[MSandRebel]

Silly question, but do you have it locked in 4 wheel hi?

 

[beepster]

ECO mode. Stops fueling 4 of the cylinders. It is off when the truck is in tow/haul mode or if you manually put the truck in 6th gear with the +/- button. If you leave it in 6, it will still use all the gears but that is what shut MDS off on my 16. I would think it would work the same with 8 spd.

Thanks!

 

[Sgambots91]

I dunno how you got that much miles my tank would go about 700 to 750km on 80 percent highway commute which is 430 to 460 miles

he has the bigger gas tank option...32 gallons

 

[Sgambots91]

2019 Warlock quad cab hemi

eibach springs
Bilsteins on 3rd notch
275/60/20 Nitto ridge grapplers
2” wheel spacers

averaging 19.3 right now

Good amount of highway driving

 

[Ram Prasad]

I have the limited 2020 with 3.92 and etorque. I get 15mpg in town and barely 19 on freeway. Also I am yet to experience the “power” of v8. I have to press the throttle to get it. It fully stock and have done 3500 miles till now. The acceleration from stop is worse than my Kia

 

[DRkNESS]

Shoot I have the 3.92 and a 5” lift and I average 9.2 mpg daily lol.


Sent from my iPad using Tapatalk

 

[Ram Prasad]

I have the limited 2020 with 3.92 and etorque. I get 15mpg in town and barely 19 on freeway. Also I am yet to experience the “power” of v8. I have to press the throttle to get it. It fully stock and have done 3500 miles till now. The acceleration from stop is worse than my Kia

The throttle felt light in my Kia (sorento v6). And had great acceleration from stop. For the first few months had knee pain riding this truck as throttle felt
Heavy and any uphill felt super slow.

had it not been for this post I would have thought this was normal

I am stil under warranty. What’s the best way to have the dealer look into this? What should I check for myself to see if something can fix it

I am new to trucks and had it not been for this post, would have thought this is normal

 

[turboguard]

Definitely not normal for the hemi...I have 3.92 2WD stock except for a Carven muffler, and just driving a short highway to work and around town I can average 18 mpg if I keep my foot off it at stops. Still has ridiculous passing power even at 60mph. Let us know if you figure it out!