Ram Heavy Duty Forum

Register a free account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members through your own private inbox!

Average Cummins HO mpg - unloaded

Gkockrow

Member
Joined
Aug 24, 2021
Messages
77
Reaction score
24
I chose the Aisin for the durability, and not the HO for the HP. The HO is nice, but torque management is always present, so if you can live with the 68rfe, then that’s your ticket if your not towing 30K daily.
That is also why I got the HO in my 2022 3500. Had 68RFE in my 2017 2500 and had some scary bad shifts in mountains towing 10,000 lbs fifth wheel. Don’t know about torque management. Towing get 10.4 to 12 at under 65 mph. Empty got 21 once on 500 mile trip. Mostly 18-19. With 10000 miles on truck.
 

slvrsix7

Active Member
Joined
Jun 16, 2021
Messages
107
Reaction score
114
15 mpg average unloaded. Mostly rural roads and around town. Can do 18-19 mpg all hwy. I'm on 35s.
 

Chriss626

Active Member
Joined
Jan 1, 2022
Messages
54
Reaction score
103
Man I am jealous of the mpg everyone is getting. My SRW HO Mega gets 12 mpg empty. The 3 inch lift and 37 sure doesn’t help. I’m only at 2k miles so hopefully it breaks in and gets better mileage and I’m in California with diesel over $6 a gallon ouch!
 

MEGA HO

Well-Known Member
Joined
Jul 20, 2020
Messages
1,060
Reaction score
1,484
Location
Alberta
Man I am jealous of the mpg everyone is getting. My SRW HO Mega gets 12 mpg empty. The 3 inch lift and 37 sure doesn’t help. I’m only at 2k miles so hopefully it breaks in and gets better mileage and I’m in California with diesel over $6 a gallon ouch!
Wow this is bad! Your spedo / odometer error is over 10% with 37s vs stock size, hope you re-calibrated the spedo for 37s.
I know I took a hit with 35s but 37s are exponentially worse!
 

darrellr

Member
Joined
May 24, 2022
Messages
69
Reaction score
66
Why should it have a negative impact if you revert back to stock?
And to answer "what gives" question, your is a dually with 4.10 gears.
My HO is a SRW and prior to getting rig of stock tires I was getting just under 20mpg on HWY. Got a get of 35/12.5r20 Nittos installed which are larger, wider and much heavier tire and my mileage dropped to 18 (not accounting the odometer error about 5-6% due to a larger tire).
Fun fact: red diesel burns much better and much better fuel economy.
Sold my camper and a guy who bought it is a farmer, his truck wasn't set up yet to transport campers so he asked if delivery is an option. I said yes but you'd have to at the very least pay for my fuel (700kms round trip so one tank of fuel). He said no problems he's got plenty. Dropped off the camper, was nearly empty when I got there (60kms to empty according to computer) so took a full tank of red. I'll tell you that tank was the best tank of fuel that went through my truck, got almost 20.5 mpg out of that tank and that is not accounting for the tire size difference, probably closer to 21mpg in reality. Much better than I ever got with stock tires.
1. My DRW is 3.73 gears, not 4.10 gears, so again, this should be better for mileage.
2. It did not come with stock. It came with the larger tires. Stock tires were LT235/80R17E. The dealer put 35x12.5x17 on it. I returned to the stock size. I would have expected the 35" tires to get worse mileage than stock, which is most of the reason I switched to stock size. Mine had a 10% difference in diameter, and I corrected mileage accordingly when measuring previously.
 

GPurcell01

Well-Known Member
Joined
Oct 3, 2021
Messages
551
Reaction score
890
Location
Lone Star State
Man I am jealous of the mpg everyone is getting. My SRW HO Mega gets 12 mpg empty. The 3 inch lift and 37 sure doesn’t help. I’m only at 2k miles so hopefully it breaks in and gets better mileage and I’m in California with diesel over $6 a gallon ouch!
You must have a heavy foot or sit in a lot of traffic lol. Has the speedometer been recalibrated? I'm averaging 17 with a similar setup. Being a pawpaw driver has got me to 18 mpg lately
 

John Jensen

Well-Known Member
Joined
Feb 11, 2020
Messages
1,206
Reaction score
1,060
I just went 949 miles in the 2020 in my signature. Not towing, all on the freeway and highways, from 65mph to 90 mph, most at 80 mph.
The EVIC was 16.2 mpg, hand calculated 15.5 mpg. EVIC best was 16.9 {level road}, worst 14.2 (mountains}.
 

Chriss626

Active Member
Joined
Jan 1, 2022
Messages
54
Reaction score
103
You must have a heavy foot or sit in a lot of traffic lol. Has the speedometer been recalibrated? I'm averaging 17 with a similar setup. Being a pawpaw driver has got me to 18 mpg lately
Speedometer has not been recalibrated. I lot of local and idling but still every time I look at the trip odometer the mpg drops lol!
 

Brutal_HO

The Mad Irishman
Staff member
Joined
Feb 1, 2020
Messages
12,157
Reaction score
21,745
Location
Douglas County, CO
I just went 949 miles in the 2020 in my signature. Not towing, all on the freeway and highways, from 65mph to 90 mph, most at 80 mph.
The EVIC was 16.2 mpg, hand calculated 15.5 mpg. EVIC best was 16.9 {level road}, worst 14.2 (mountains}.

Which tune?

It's not fair to state tuned mileage in a thread about mileage unless you divulge you're running a tune. You don't call out the tune in your sig either John. :)
 

GPurcell01

Well-Known Member
Joined
Oct 3, 2021
Messages
551
Reaction score
890
Location
Lone Star State
Which tune?

It's not fair to state tuned mileage in a thread about mileage unless you divulge you're running a tune. You don't call out the tune in your sig either John. :)

These newer trucks do not see much gains at all with mileage from tuning. I really wanted to see better numbers though.
 

RVTRKN

Well-Known Member
Joined
Apr 4, 2020
Messages
421
Reaction score
276
I go off the EVIC to get general MPG info, you would have to reset the EVIC on the different terrains you drive, and even that is not accurate enough. So on my trip to Salt Lake I let the EVIC just average out over the the entire trip. But I watched the MPG display to see my current MPG and could see improvements, or not, on different terrains. I was pleased to see an occasional 19 on the EVIC for an average. But once I started climbing towards Denver the MPG dropped quick. The Rocky's was surprisingly better than expected, the climbing MPG was averaged out by the decent MPG and was @ 18ish. Its quite a climb from Kansas to Denver, not enough to really feel but it shows up with poor MPG.
 

Brutal_HO

The Mad Irishman
Staff member
Joined
Feb 1, 2020
Messages
12,157
Reaction score
21,745
Location
Douglas County, CO
I go off the EVIC to get general MPG info, you would have to reset the EVIC on the different terrains you drive, and even that is not accurate enough. So on my trip to Salt Lake I let the EVIC just average out over the the entire trip. But I watched the MPG display to see my current MPG and could see improvements, or not, on different terrains. I was pleased to see an occasional 19 on the EVIC for an average. But once I started climbing towards Denver the MPG dropped quick. The Rocky's was surprisingly better than expected, the climbing MPG was averaged out by the decent MPG and was @ 18ish. Its quite a climb from Kansas to Denver, not enough to really feel but it shows up with poor MPG.
The crappy uhaul I drove to Denver in the early 90's sure did notice it. :) :)
 

tchur1

Well-Known Member
Joined
Jun 23, 2021
Messages
667
Reaction score
706
On a fully stock setup with just over 6k miles on my HO SRW I would get about 18 around town (my around town isnt stop and go, its like 15-20 minute drives at 40-50 MPH) and about 20 on the highway. However I just put 37x12.50R17 KM3s on it and ive seen it drop to about 18 on the highway and 16 around town. I drive like a grandpa so that helps but as expected the larger tires have impacted it by about 20%.
 

John Jensen

Well-Known Member
Joined
Feb 11, 2020
Messages
1,206
Reaction score
1,060
Which tune?

It's not fair to state tuned mileage in a thread about mileage unless you divulge you're running a tune. You don't call out the tune in your sig either John. :)
Ran the whole 949 miles on Calibrated's optimized stock tune. Switched to sport for two passing events.
 

thecastle

Active Member
Joined
Mar 27, 2022
Messages
152
Reaction score
100
I get 17.8mpg unloaded, at 75-90mph on the highway. 15.8 around town. 8.5-10mpg (mostly 8.5+/-) while towing a travel trailer. Truck is stock, though I have a topper on the bed, which may help with the aerodynamics. The only time I see in the 20+ range is driving 45-60mph.
 
Last edited:

H3LZSN1P3R

You're doing it wrong
Joined
May 29, 2020
Messages
9,155
Reaction score
8,300
I get 17.8mpg unloaded, at 75-90mph on the highway. 15.8 around town. 8.5-10mpg (mostly 8.5+/-) while towing a travel trailer. Sadly the ram 3500 won't set cruise higher than 85mph, but I get it, it a truck. Truck is stock, though I have a topper on the bed, which may help with the aerodynamics. The only time I see in the 20+ range is driving 45-60mph.
Alfaobd can change the cruise limit
 

Brutal_HO

The Mad Irishman
Staff member
Joined
Feb 1, 2020
Messages
12,157
Reaction score
21,745
Location
Douglas County, CO
I get 17.8mpg unloaded, at 75-90mph on the highway. 15.8 around town. 8.5-10mpg (mostly 8.5+/-) while towing a travel trailer. Sadly the ram 3500 won't set cruise higher than 85mph, but I get it, it a truck. Truck is stock, though I have a topper on the bed, which may help with the aerodynamics. The only time I see in the 20+ range is driving 45-60mph.

It won't initially set cruise if you're going above 85, but if set at 85 or below, you can push it all the way to the limiter using the + button (long press for 5MPH increments).
 

tyler2you

Well-Known Member
Joined
Sep 13, 2021
Messages
372
Reaction score
816
Location
Huntsville, AL
Stock set-up (SRW, CC), 14 around town with some stop/go, 17.5 highway at 65-70 MPH, and 11-13 towing a 7500 lb TT on mostly flat highway at 65 MPH. Truck has a little over 4K on it.
 

Users who are viewing this thread

Top