Towing MPG with GM 3.0 diesel 1500 pickup

[tallmandan]

With towing MPG certainly a bigger consideration these days, I thought I would share the fuel economy numbers from my last two trips up into the Colorado mountains and back while towing my LEII.  (Water tank full outbound and empty on return) This is a stock 2021 Silverado 1500 with the 3.0L diesel in-line 6 cylinder.  If you are considering a new tow vehicle, this truck has been solid and comfortable.  Power and control towing both up and down the mountain passes in Colorado.  The only shortcoming is limited payload in the truck and use of WD hitch, as has been discussed here for all half ton trucks - but these haven’t been a problem for me so far.  Almost 17k miles and zero problems.

[rideandfly]

Appreciate you posting the fine fuel economy of your 2021 Silverado 1500 3.0L Diesel towing Ollie in the Colorado mountains.

We tow with a gas 2WD 2022 Tundra SR5 1/2 ton pickup getting 14 to 15MPG, it does not get as good of fuel economy towing that your getting, but it's working fine for us towing our LE2, too!

Great looking rig, too!

[Trainman]

I thinking of a Jeep Gladiator with the EcoDiesel 3.0, 260 HP and 442 lbs. of torque, should do the job.

trainman 

[ChrisMI]

Currently in our area diesel is about 15% more expensive than regular.  Seems reasonable given the higher stored energy. Normally I expect 25 to 30% better mpg but higher maintenance costs for sure. With our one ton pulling the E2 we get just over 15 with the cruise set on 70, higher on the backroads.  I’m curious what a gas 3/4 or 1 ton would get with the cruise set at 70…

[CnC]

With a 2021 Ram 1/2 ton eHemi pulling an E2 with a camping load in the bed...  A recent 5000 mile trip through mountains and flatlands got as good as 16.5 mpg and as poorly as 11.5 mpg per tank of gas.  The best day was with tailwinds - the worse day was climbing elevation from 1200 ft to 7000 feet.  We typically average around 14 mpg at 65 mph per tank on days without head/tail winds.  The Ram has lots of pulling power and the tow/haul function holds the cruise except on VERY long 6 degree down grades.

Charlie.

[Allen Lee Rohner]

Mr. tallmandan,    Are you running your Silverado 1500 in the Tow/Haul Mode?

Allen

[Trainman]

Does your Colorado Diesel have the DEF system as the Jeep Gladiator has, maybe this is only used on EcoDiesel engines and regular diesel powered vehicles do not have the DEF system.  Do you think that the EcoDiesel will be the engine of the future, or should I say it will be mandatory to pass inspection for the EPA in the future. I would rather not have the DEF system, but if I want a Jeep Gladiator EcoDiesel, which I do, then that's what you get. From what I have seen on YouTube the Jeep Gladiator EcoDiesel mileage is pretty much the same as the Colorado, but a Gladiator fully equipped is in the $60,000 plus price range, which it becomes two different vehicles.

trainman

[John E Davies]

You aren’t going to get away from DEF unless you do an illegal “delete”. Which would get your Ollie black and oily😬

https://donotdpfdelete.green/what-year-trucks-require-def/

John Davies

Spokane WA

[Cameron]

Hello, I'm also towing with the new(ish) GM engine, the 3.0 diesel, which is in both the Chevy and GMC half-ton trucks. On a 800-mile trip a couple weeks ago I averaged 16.7 mpg. Before the recent changes in fuel prices, back when diesel was less than unleaded, I was very happy. Now, not so much. Plus i do have to add in DEF, which I used to get at Walmart (store brand) for $8 but now it's $14 for a 2.5 gal jug. When not towing, the DEF lasts for a long time. When towing, the engine uses more DEF. So, even though right now I don't like that I'm paying more for fuel than anyone else, I do like the mileage and the low-end torque that makes it a breeze at the freeway onramp or going up steep passes. 

 

PS to Tallmandan: I've done my own calculations on mileage when filling up and found that I'm actually getting 1 to 3 mpg more than what the truck computer says. 

[ScubaRx]

On 6/16/2022 at 6:34 PM, tallmandan said:

With towing MPG certainly a bigger consideration these days, I thought I would share the fuel economy numbers from my last two trips up into the Colorado mountains and back while towing my LEII.  (Water tank full outbound and empty on return) This is a stock 2021 Silverado 1500 with the 3.0L diesel in-line 6 cylinder.  If you are considering a new tow vehicle, this truck has been solid and comfortable.  Power and control towing both up and down the mountain passes in Colorado.  The only shortcoming is limited payload in the truck and use of WD hitch, as has been discussed here for all half ton trucks - but these haven’t been a problem for me so far.  Almost 17k miles and zero problems.

Have you noticed that when the tow/haul mode is engaged, the last gauge changes from an amp meter to transmission temperature?

[Cameron]

Yes, when you plug in the trailer cable to the bumper, it notifies the software that there's a trailer there. The software then reminds the driver to put the truck into tow/haul mode, which switches over the dash gauges to include a tranny temp gauge. It also tells the tranny to act like a trailer brake (common on diesels) when going down hill so that it shifts to a lower gear to try to hold your downhill speed and not rely on braking.  The trailer tab on the center screen also shows trailer tire pressure and temp (when the GM TMPS is installed), and it also keeps a trailer odometer so I know how many miles I have on the Ollie. There's a bunch of other stuff but overall I'm very happy with both the diesel engine and with the trailering software on the truck. I know most of the companies have something similar on new models but so far so good with the Chevy/GMC system.

[Trainman]

My RAM 1500 5.7 4x4 has the tow package and I do put it into tow haul mode when pulling the trailer. I will say here that for some reason I tend to get better fuel mileage when not in tow haul mode pulling the trailer, I guess it could be because the transmission is working at a different ratio, I would say 2-3 hundred RPM less. I can say that I have taken off and when I forgot to go into Tow Haul Mode I have driven many miles and really didn't notice the vehicle performing any different. This probably has something to do with having the 5.7 Hemi and the 3.92 gears, which give it a good towing ratio to start with. When in Tow Haul Mode there are other things the truck does to make towing safer and obviously work easier, so I use it when I don't forget.

trainman

[Allen Lee Rohner]

Guidelines as per GMC Sierra 1500 user Manual.

Tow/Haul Mode is designed to be most effective when the vehicle and trailer combined weight is at least 75% of the vehicle's Gross Combined Weight Rating (GCWR).

11500 lbs Oliver +Truck / 15000 lbs AT4 GCWR = 77 %

Looks like I am pushing over 77% since the weighing of 11500 lbs does not include all my gear and supplies.

Allen

[Allen Lee Rohner]

On 6/18/2022 at 12:31 AM, Allen Lee Rohner said:

Mr. tallmandan,    Are you running your Silverado 1500 in the Tow/Haul Mode?

Allen

Appears you are running in Tow/Haul Mode, on your Instrument Cluster I see the Tow/Haul Mode indicator light is  on.

Allen

  

[tallmandan]

@Allen Lee Rohner  Yep.  Always tow my Oliver in Tow/Haul Mode.  As @Cameron said above, Tow/Haul mode enables the whole GM towing tech system including the trailer mileage tracker, TMPS (I have the GM sensors in the Oliver wheels), trailer circuit detection, engine braking, camera views, trans temp on the cluster, etc.  I've been very happy with it.   Just returned from my 3rd weekend boondocking trip in a row (Yay!) up in the mountains of Colorado.  This trip I again got 18 MPG towing on 360 miles round trip so that's been consistent.  DEF is more expensive now along with diesel as @Cameron said but I still feel like I made the best choice for me...deisel engines perform well at high altitude and I've towed up to and over 9-10k feet the last three weekends.  It jams right up the long inclines and then the automatic engine braking is fantastic when coming back down.

[jim sroka]

Well my 2022 Silverado 1500 is on of the new ones with a tow pkg which includes a 377 axle and a high tow rating. I left our house in Michigan to go pick up our new Oliver after selling our 25ft Airstream on June 20th. We where load to the max in the back seat of the crew cab and some stuff in the bed . Traveled at 5 over most of the trip we averaged 66.5 miles per hour over the 694 miles when we checked into our hotel . We averaged 31.2 mph on the dash and we i topped of the tank it confirmed just a little bit better at 31.6. Picked up the trailer on Tuesday stayed overnight, load all our stuff into the trailer installed the hitch . Next morning headed home 734 miles away. This truck is a LT Crew Cab ,shortbox, four wheel drive. Got up to Nashville outside temp was 100 , on to Louisville temp 101 in stop and go traffic. Head to Cincinatti, hit a strong 30mph head windy all the way home to Port Huron MI.  Averaged 16.2 on that 724 mile return trip . Compared to my 2014 Chevy 1500 with a 5.3  I got 48% better milage on the trip down and 55% better towing with the 3.0 Duramax., and that was towing the same weight with the Airstream. If i was only towing the Oliver or the Airstream both around 6500Lbs load I would have passed on the Max Tow Pkg and probably got better milage, but I do tow a boat that goes 9400 lbs so Max Tow was the only choice. Love this motor I found myself creeping up to around 78/80 mph and the Oliver towed super.

[Cameron]

Hi Jim,

Welcome and congrats on your new Ollie. I know you're going to love it. I wonder if you got your new truck to go with your new trailer. I know I did. White, just like the Ollie. For some reason the Chevy has a better MPG rating with the 3.0 diesel than my GMC Sierra. I've had the same experience you described. Good mileage. And coming west on I-80 down the continental divide I did discover I was going 80 without noticing it, and immediately backed down to 70, but the Ollie tracks so well!! Just changed my fuel filter yesterday after 31k miles. It was clean as a whistle, but got replaced anyway. I've found that the computer is a little wonky on the DEF warnings, like warning me when the DEF gauge shows half full, and sometimes the gauge isn't so accurate. But I'm loving my 3.0.

[Allen Lee Rohner]

I only towed my Ollie about 40 miles from Home to storage on the  farm.   Just starting  my experience in the RV world and getting ready for my first trip.

Regarding towing,  what are Trailer Brake gain settings are you using on your vehicles?

[Cameron]

I've got mine at 7.5

[John E Davies]

5 hours ago, Allen Lee Rohner said:

Regarding towing,  what are Trailer Brake gain settings are you using on your vehicles?

ALL Ollies will differ, depending on brake age, adjustment, wear, cleanliness, weather, road surface and probably a few more variables. Maybe the phase of the moon …. All TVs will differ, unless perhaps they are using the same exact controller and same boost setting. Drive at about 25 mph on a deserted paved road, increase the gain until the brakes lock manually, using the lever, then back off some. Tweak the setting up or down until it feels best. Back it off when driving on gravel or they will skid. Crank it up in torrential rain when they will quit functioning entirely….

Yes drum trailer brakes are crummy, you just need to learn to make the most of that. Having a small TV with small service brakes exacerbates the situation. Folks with HD trucks tend ignore the trailer brakes for the most part when pulling a 6000 pound trailer. Being able to stop safely when the trailer brakes are not working as designed is something most new owners don’t think about when shopping for a TV, if it even occurs to them at all. Compact pickups like the Colorado are unsafe tow vehicles for the LE2 IMHO, because of their smaller brake components, the front rotors in a 2022 are 3 inches smaller than a comparable Silverado 1500.

John Davies

Spokane WA

[Trainman]

On 6/18/2022 at 8:45 AM, John E Davies said:

You aren’t going to get away from DEF unless you do an illegal “delete”. Which would get your Ollie black and oily😬

https://donotdpfdelete.green/what-year-trucks-require-def/

John Davies

Spokane WA

DEF makes no difference with me, just wondering if the Colorado has the DEF system. Another question, do all EcoDiesels in todays vehicles have the DEF system, or is engine by engine and manufactures do it to meet the EPA standards. I.E., does EcoDiesel mean it will have a DEF system.

trainman

[John E Davies]

4 minutes ago, Trainman said:

does EcoDiesel mean it will have a DEF system.

Yes it uses DEF.

https://m.youtube.com/watch?v=X80r0y7OXOg

You should at least be aware of its cost, it has been climbing and should be part of your fuel economy calculation, unless you are so financially well off that it becomes irrelevant.

https://mansfield.energy/market-news/def-prices-explode-how-to-manage-your-def-supply/

John Davies

Spokane WA

[ChrisMI]

22 minutes ago, Trainman said:

DEF makes no difference with me, just wondering if the Colorado has the DEF system. Another question, do all EcoDiesels in todays vehicles have the DEF system, or is engine by engine and manufactures do it to meet the EPA standards. I.E., does EcoDiesel mean it will have a DEF system.

trainman

GM started using the eco (tech) name around 2000 ish. All diesel engines over 25ish hp have some sort of filter on the exhaust. Those that are above 75ish hp are also required to have def. 

[Trainman]

3 hours ago, John E Davies said:

Yes it uses DEF.

https://m.youtube.com/watch?v=X80r0y7OXOg

You should at least be aware of its cost, it has been climbing and should be part of your fuel economy calculation, unless you are so financially well off that it becomes irrelevant.

https://mansfield.energy/market-news/def-prices-explode-how-to-manage-your-def-supply/

John Davies

Spokane WA

I would hope anyone looking at a Jeep Gladiator EcoDiesel is not looking at saving money, for me it's a "Jeep Thing" and the V6 gas in a Gladiator is useless in towing the Oliver. Thanks John for your response

trainman

[jim sroka]

Well a update on my 3.0 Duramax max tow PKG. 4100 miles with 2900 miles towing the Oliver or my 6000lbs boat. Average milage towing all at 70 plus 16.4 mpg and in all 7.5 gals of DEF used in all 4100 miles.  Two and a half gals of def per in 1300 miles of running 70+ plus towing the Oliver. Love this motor compared to my past 5.3 max tow PKG truck. On one short 30 flat puling the trailer it was 19 mpg running 55-60. Due have to keep a eye on it likes to climb past 80.