I just bought a used 2018 Ram 2500 4x4 long bed SLT and will be taking delivery of it next week. It has only 16,000 miles on it and was a former Enterprise rental. My last diesel was a 1974 White Freightliner with a 290 Cummins, 13 speed Road Ranger & a twin screw rear end. I have a lot of catching up to do!

My Ram has only a 32 gal fuel tank & I'm curious how many miles I can expect from it. With the bed loaded "pretty well" and a 10,000 lb 24' box trailer what sort of mileage can I expect? I'm not going to try to out qualify Mario at Indy, just move along a reasonable pace to avoid legal issues. Maybe 60 or so mph? I'll be traveling the length of California and into southern Oregon so it is mostly flat with some mountains & hills.

BTW, what generation truck do I have? It has the 6 speed auto gearbox & the 3.43 gears.

Paul

 

I would say plan for 15mpg.

 

Thanks Mike, that is better than I had hoped for. I have one leg of 411 miles and I was hoping to make that without refueling at the high cost fuel stations in between. 15 mpg would make that.

How far will a tank of DEF last? The gauge currently reads 3/4 full, will that last 1000 miles?

The last truck I owned was a 1984 Ford F-250 with a 460. It got around 7 mpg empty or loaded, towing a trailer or not.

Paul

 

I think it is do-able if you do 60mph. I do 70 in my 2nd gen and get 16. However, maybe the latest gen guys will know more.

 

15 mpg might be a bit on the high side but doing 60 might get you there on the flats. The def should last 1k miles. The weight in the bed won’t be a big deal on the mpg but the frontal area of that trailer will. When I tow our 30’ fifth wheel at 10k lbs I can get 13ish but that is about it on a good day. My second gen towing would do about the same when I had it but it definitely got better empty mileage than my 17 does

 

I am having a 24' box trailer built to spec with ETrack and a generally heavy duty build. It will be heavy. It will look much like the one below. It will be moving a lot of air as it goes!

 

I have almost the same truck except its a '16. I have seen a high of 12MPG towing a 33 TT weighing about 8700lbs and a truck full of family. That was towing in 5th gear and about 65MPH. I've seen a low of about 9 going into a headwind. I have done a 3000 mi round trip pulling the same load above and used maybe 1/2 a tank of DEF with some around town driving in there too. I would say 4000 is easy on a tank of DEF.

 

That DEF last longer than I thought. I just purchased 10 gallons of the stuff for the 15,000 miles or so I might be putting on the truck during the move, It sounds like I may have enough to last for some time. What is a 33TT? Is that a camping trailer?

How accurate is the onboard milage computer in the instrument cluster? If its showing 12 mpg I'm going to have to stop for a splash 'n go on my last leg. If it shows 15, I might stretch it out . . .

 

33TT is a 33ft Travel Trailer.

 

Today's data on a 2010 pre-def truck. Towing a 15k (loaded weight, we are full-timers) fifth wheel. I tow mostly in fifth gear, depending on wind, terrain, and EGTs at 60-65 mph. Today we were headed East on I-90, from Salem, SD, to Jackson, MN. Short tow of +/- 130 miles. Deleted with a RaceMe Ultra running the 30 hp tune. Used 1/4 tank of diesel. Dash meter showed an average of 10 mpg. SW winds at 15-20 mph, so SOME sideways tailwind. I know that when I get into a good 10-15 mph headwind, mileage sucks (<9 mpg) and running in 5th gear I struggle to maintain 60 mph with EGTs under 1100.

And no, don't rely on the dash mpg reading. It's an average...

Bob

 

The technical term for that indicator is "Lie-o-meter".

My '15 averages 10-11 mpg on long trips hauling my Fox @ speed limits. Not really comparable to the terrain or speed you intend to travel on as I go through many states at a time, mostly in the West. ~~~~~
Back to morning brew . . .

 

I guess I better stick to the 10 mpg estimate for trip planning and count on an extra fuel stop for a splash & dash partway through that last 411 mile leg.

BTW, I see one mention of EGT. Does the instrument cluster show this figure or do you have an extra gauge? Some years ago I was a general aviation pilot and flew aircraft with such gauges. We used them for determining the correct fuel/air mixture for specific power settings & altitudes. What do you do with the information on a Cummins in a pickup truck?

Paul

 

Don't know about the newer trucks but my 2010 didn't have one visible on the dash. When I deleted, put an EGT probe in the EGR cooler block-off plate and connected to my tuner. I think the 4th gens monitor the EGTs and if it starts getting too high will de-fuel. Not sure of that but maybe someone who knows for sure will chime in. If they get too high things will start to melt. I try to keep mine under 1200 but have heard 1300 is OK for brief periods.

 

I have a little real world experience now with the milage. With a fully loaded bed and a the trailer also loaded pretty well I got 10.8 mpg going from Fullerton, CA (near Disneyland) to Klamath Falls, OR a distance of 730 miles climbing two mountain ranges. This was a pretty steady 58 mph mostly on cruise control and constrained to 5th gear. The motor had plenty of power & I'm not sure I ever used all it had even climbing hills or passing. I did make Santa Nella going up and pulled in just as the low fuel light came on.

Coming back over the same route with an empty bed & trailer it got 13.5 mpg. This contrasts to more than 25 mpg running empty to AZ to pick up the trailer. The trailer moves a lot of air and that seems to make more difference than the weight.

Paul