Can the 3.0 Duramax Diesel Tow? My 1,425-Mile Trailer Test

You’ve seen the window sticker. You’ve read the marketing. And if you’re like me, you’ve probably asked yourself: “Okay, but can this little 3.0 inline-six Duramax actually tow… like, for real?”

I decided to find out the hard way: hook up a trailer, point the truck toward California, and see what breaks first—my patience, my DEF tank, or the laws of thermodynamics.

The Setup

• Truck: 2024 Silverado with the 3.0 Duramax

• Trailer: 18-foot enclosed unit, empty but still a 3,000-pound brick of wind resistance

• Weather: triple-digit desert heat

• Starting mileage: 12,367

• Fuel: topped off

• DEF: topped off (this will matter… a lot)

• Additives: yes, because I’m curious like that

• Gauges monitored: EGTs, soot %, intake temps, oil temp, charge-air cooler temps, and DEF level

Basically, I set this thing up like a rolling science experiment with the entertainment value of a guy talking to himself for 1,400 miles.

The Climb, the Heat, the Panic

We didn’t even make it 75 miles before my truck started flashing DEF consumption warnings like it was trying to win a slot machine jackpot.

At 90% DEF remaining.

Yes, you read that right. Ten percent down and the dash was already yelling “REFILL NOW OR ELSE.” If you’re new to diesel ownership, this is the DEF system crying wolf. It assumes that if you’re pulling like this for 1,000 miles straight, you’ll run out. Spoiler: I wasn’t even close.

Meanwhile, the truck itself was working overtime:

• Engine oil temps spiking to 270°F

• EGTs climbing past 1,200°F

• Transmission temps? A calm 170°F (shout-out to the PPE bypass)

• My nerves? Overheating worse than the oil

I tried Sport mode. I tried Tow/Haul. Eventually, I tried “ignore the warnings and hope the truck figures it out.”

DEF: The Real Enemy

Let’s talk DEF. In theory, DEF is there to keep emissions clean. In practice on this trip, it felt like the truck was mistaking DEF for Gatorade and chugging it every 200 miles.

Over the full 1,425-mile trip, I poured in about 10 gallons of DEF. For perspective, that’s:

• One full jug every 140 miles or so

• More DEF stops than snack stops

• And enough dashboard warnings to make me question every life decision that led to towing in 110°F heat

The kicker? Even after filling the tank to 100%, the dash would still scream “DEF EMPTY—SPEED LIMITED SOON.” It eventually reset… sometimes.

Fuel Economy Reality Check

This is where things get painful.

Final MPG: ~11.1 over the entire trip.Not terrible for towing in the desert with a brick behind you… until you realize how often I was fueling up. Every 145–200 miles, I was back at a pump.

On the way out, things looked rough—single-digit MPG stretches, oil temps hovering at “spicy.”On the way back, cooler weather and a fresh air filter helped. The truck held gears better, ran cooler, and didn’t feel like it was screaming at redline just to hold 70 mph.

Can It Tow?

Here’s the honest answer: Yes, but…

• The 3.0 Duramax can tow 3,000–4,000 pounds without falling apart.

• It’ll even pull grades like Cajon Pass at highway speeds if you’re patient and okay with watching your oil temp climb.

• But the DEF system? It loses its mind under sustained load. I burned 10 gallons and lived with constant false warnings.

If you’re towing occasionally, boats, small campers, or flat trailers—it’s fine.If you’re towing enclosed trailers in the desert for 1,400 miles… you’ll survive, but your DEF jug budget may not.

The Big Takeaway

After two days of heat, regen cycles, and DEF drama, I ended up back home with:

• 1,425 miles traveled

• 11.1 MPG average

• 10 gallons of DEF consumed

• A newfound respect for this little diesel… and a stronger dislike for DEF than I had going in

So, can the 3.0 Duramax tow?Yes.But it’s a bit like bringing a pocketknife to a sword fight—you can win, but it’s going to take some finesse, some patience, and definitely more DEF than you bargained for.