GMC Sierra 3500 Denali HD

We celebrate National Hunting and Fishing Day with a trip in the GMC Sierra 3500 Denali HD to San Diego, California, and beyond.

GMC Sierra 3500 Denali HD
GMC Sierra 3500 Denali HDJim Hendricks

The PR folks at GMC approached us with an interesting proposal. Show the Boating followers the proper way to celebrate National Hunting and Fishing Day (September 23, 2017). To help with this quest, GMC loaned a beast of a truck – a Sierra 3500 Denali 4WD dually powered by a Duramax 6.6L V-8 turbodiesel.

GMC Sierra 3500 Denali HD
GMC Sierra 3500 Denali HDJim Hendricks

GMC actually challenged us to tow our boat to one of the most remote and/or best-hidden fishing spots using the 3500. They left it to us to choose the destination, and in California, there's aren't too many secret spots. The backwaters of San Diego Bay might qualify – this is one of few spots along the coast of the Golden State where you can catch bonefish. Yes, I said bonefish – the same kind of fish that Florida anglers pursue on the flats. Not that many anglers know about it. Also, San Diego is the closest U.S. port to our border with Mexico on the West Coast and the remote fishing spots in Mexican waters. So off to San Diego we went in the 3500, towing our 6,000-pound fishing boat.

GMC Sierra 3500 Denali HD
GMC Sierra 3500 Denali HDJim Hendricks

We left at about 2 a.m. on the 1.75-hour tow from my home near Los Angeles to San Diego. As my two-man crew lamented, we really needed a bigger boat to tow test with this diesel dually. The crew cab with a diesel and 3.73 axle ratio boasts a 20,000-pound tow rating, so it was definitely overkill on this trip. While I worried about an overly stiff suspension and a jarring ride, the ride of the 3500 proved smooth, quiet and comfortable. The Denali HD also bristles with safety technology, including lane-change cameras, lane departure warning (it emits a startling buzz on affected side of the seat), StabiliTrak with trailer-sway control, front and rear park assist and a rear-vision camera. Interior comfort features include electrically adjustable front bucket seats, dual-zone climate control, power sunroof, cooled/heat front seats, touch-screen navigation, 4G LTE Wi-Fi hotspot, Apple Carplay and much more.

GMC Sierra 3500 Denali HD
GMC Sierra 3500 Denali HDJim Hendricks

I was also impressed with the fuel efficiency of this vehicle. The 6.6L Duramax V-8 turbodiesel, linked to an Allison 6-speed automatic transmission, averaged 11 mpg while towing. Given the light load, I suspect non-towing fuel economy would be a mile or two more per gallon, depending on how heavy-footed you are. Diesels used to be loud and rattily, but the Duramax is supremely quiet, even during hard acceleration. Launching and retrieving the boat at Pepper Park Launch Ramp at the back of San Diego Bay was a piece of cake. This truck has beaucoup power and, with six tires on the pavement and 4WD, plenty of traction.

GMC Sierra 3500 Denali HD
GMC Sierra 3500 Denali HDJim Hendricks

We fished in fairly remote Mexican waters – about 30 miles below the border – for two days, and brought home 14 yellowfin tuna (aka ahi) and six mahimahi. With plenty of fish in the cooler, we decided to save the backwater bonefish adventure for another day. Our trip home was as comfortable as the trip south, and we rewarded ourselves with a few road tunes courtesy of the 3500’s SiriusXM radio.

GMC Sierra 3500 Denali HD
GMC Sierra 3500 Denali HDGMC

One thing I have to say about the 3500 dually – it's not a truck for everyone. Just running to the grocery store in this vehicle is fraught with, well, adventure. It's not a truck you can park anywhere. It is a truck for guys who tow heavy loads – boat/trailer combinations in the 12,000- to 15,000-pound range. However, there are disadvantages to such a beast. It is long, wide (think big hips) and has a wide turning radius. Whether towing or not, you need to plan your exit strategy carefully and ahead of time, whether pulling into a tight parking lot or a potential dead-end street. There's also the price -- $69,585 after package discount. That's less than what I guessed, but still a hefty tariff. That said, in heavy towing applications, the GMC Sierra 3500 Denali HD DRW is the king of the road.