2015 GMC Sierra Crew Cab Review - America: The Truck

Mark Stevenson
by Mark Stevenson

2015 GMC Sierra Crew Cab SLT 4×46.2-liter OHV V-8, direct injection, cylinder deactivation, CVVT (420 horsepower @ 5,600 rpm; 460 lbs-ft @ 4,100 rpm)

Hydra-Matic 8L90 8-speed automatic

15 city/21 highway/17 combined (EPA Rating, MPG)

16.5 mpg, mostly city driving while yelling “AMERICA!” at full trot. (Observed, MPG)

Tested Options: 6.2L Ecotec3 V-8, navigation, polished exhaust tips, sunroof, spray-in bedliner.

As Tested (U.S.):

$52,300 w/ $1,195 destination charge ( sheet)

As Tested (Canada):

$59,615 w/ $1,795 destination charge and A/C tax ( sheet)

A farm, lots of mud thanks to rain from the previous day, and a dose of sunshine to dry out the ground just enough so my feet wouldn’t lose their boots in the slop. This is the perfect location — along with the perfect conditions — to test one of the latest from the pickup crop, the 2015 GMC Sierra.

Or is it?

Under the hood of the SLT-trimmed Sierra sits a V-8 less suited to farm duty and better equipped for automotive trolling.

Before we get into the meat and potatoes of the Sierra, I have a small announcement to make. TTAC now has an off-road area for testing trucks and SUVs. Sort of. It probably won’t be fully available for us for a little while, but shenanigans will be had before the end of the summer. Here’s hoping the automakers send us some metal so we can put it to the test at this newfound playland.

As for this Sierra, well, it isn’t a farm truck. Hell, it’s barely a work truck. The Sierra is available in four different trim levels — base, SLE, SLT and the top-trim Denali. Our SLT-trimmed tester arrived with its bench seat still intact, which is great for mid-summer-romance canoodling and one of the reasons girls dig guys with trucks, maybe.

Interior configuration aside, the real news for this Sierra is under the hood. The 6.2-liter Ecotec3 V-8, with its 420 horsepower and 460 pounds-feet of torque, is a nod to old-school solutions to making power and a pragmatic approach to efficiency. The pushrod V-8 might sound antiquated next to the new turbo and diesel units from Ford and Dodge, but that doesn’t make it any less valid.


Big power, these days, is easy to make. When you can go out and buy a family sedan with over 700 horsepower for under $100,000, power is almost insignificant — unless you are also trying to pair that power with fuel economy.

Previously only available on the chrome-laden Denali, the 6.2-liter V-8 now finds its way to lesser, more restrained trims like this SLT model — and it’s a punisher. Paired with fairly unassuming looks, the bigger V-8 will give a lot of performance cars a run for their money. We aren’t talking M3-beating performance here. After all, regardless of what you folks may think, I am not completely delusional. Yet, with this combination you could definitely catch a few people off-guard at stop lights.

That would be completely true if it wasn’t for the incredible amount of latency experienced from a standing start. It feels like you can count the number of seconds between your foot depresses the accelerator and the V-8 comes to life. The experience is painful. At busy intersections, you are left questioning the Sierra’s ability to get out of its own way and, more importantly, that of oncoming cross traffic. Why that latency exists, I’m not quite sure. It could be a matter of many causes. It surely isn’t because the engine is lacking power or torque, however.

The modern six-speed automatic transmissions from GM have always impressed me with their smooth-shifting antics regardless of the lazy speed in which they perform those shifts, but the eight-speed slushbox in our tester seems to have lost a little bit of its refinement while still retaining its lethargic nature. Paired with the big eight-cylinder engine, shifts can be abrupt at mid-throttle and deeper into the revs. Thankfully, when putting around town, the Hydra-Matic 8L90 exhibits the same silky demeanor as its six-geared counterpart.

In reality, the eight-speed is meant to deliver increased efficiency and not Rolls-Royce shift quality. In that regard, and in combination with the L86’s cylinder deactivation turning the V-8 into a V-4, direct injection, and CVVT, the V-8 is rated similarly to the Ram 1500’s 5.7-liter HEMI V-8 on fuel economy while delivering 25 more horsepower and 50 more pounds-feet of torque. I call that a win. For the turbo and diesel averse, it’s a no brainer if you’re looking for big numbers. And comparing the Ecotec3 with the HEMI gives GM a win for payload and towing by multiples of hundreds of pounds — when properly equipped, of course.


This category is the only one that separates a GMC from a lesser Chevrolet and it’s also wholly subjective. Personally, I’d take the Sierra over the Silverado for the extra half sandwich it costs for a cleaner, three-lettered grille and headlights that don’t appear to be lifted from one of Michael Bay’s “Transformers.” Aft of the front fascia, the two trucks — save their badging and color choices — are completely identical.

Compared with the F-150, the Sierra looks much more restrained and professional, less Tonka-like and thrown together. Ignoring that the Ram Rebel grille exists, I think the FCA offering is the most handsome of the domestics — and easily much better looking than the Tundra and Titan. Again, wholly subjective.

In profile, the squared-off wheel wells are trimmed well in off-road-looking plastic. However, ignoring that GM design cue, the Sierra and Silverado are slab-sided pickups — and that’s totally, perfectly, absolutely okay. The day I see a BMW-esque flame surfacing on a pickup is the day I give up on humanity.

Around back, GM ignores fancy RamBox and Ford retract-a-step features for customizable anchoring solutions and a notch cut into the bumper for pickup bed ingress. GM seems much more pragmatic when it comes to their trucks, preferring simpler, usable solutions over flashy, marketing-friendly buzzword features like those found on Fords and Rams.

But, if there’s one thing that bugs me about GM trucks, it’s the bed. I will freely admit this is something my somewhat OCD brain thinks is an issue and probably isn’t … but! the ridges in the bed floor are all wrong. Being someone who hauls motorcycles in the pickup beds, I like the very middle ridge in the bed floor to go down, not up, so I can put the tires of the motorcycle I am hauling in the center groove and know for certain the weight of said motorcycle is evenly distributed side-to-side. Also, it helps ease my unfounded worries that the motorcycle tires will slip to one side or the other riding atop one of the ridges. Yes, I know this is a me issue.


If you want a quiet place to do your work, you can’t find a much better cabin than that of GM’s full-size pickups. Thanks to clever sealing solutions and active noise cancellation, the Sierra is “library silent” — that is unless you put your foot down for a quick scoot to 60 as the 6.2 still makes enough of a ruckus to be heard loud and clear.

If you order a Sierra without the optional captain’s chairs up front, the middle can be used as a console or additional seat for drive-in theater trips. Also, since the console isn’t fixed, the floor space is open from side to side. Transporting a very important package along with a very important person? You can keep both up front.

The seats themselves, while they do provide a wide range of adjustability along with the moveable steering wheel and pedals, didn’t provide the best comfort. It wasn’t until the very end of the week that I found a seating/pedal/steering wheel position combination where I was somewhat comfortable. The seat leather is just fair. The overall design of the interior is OK.

In the back row of our crew cab tester, space is ample and the seats are easy as pie to fold up. There is no latching. They simply flip up and stay there — sometimes. If you plan on traversing some rougher roads, those latchless seats will flip back down without warning.

All that said, I like the Ram interior more overall, but this bests the F-150 in my eyes.


I still do not understand how navigation is an option on a $50,000 pickup, especially when the cost of it is probably negligible for the automaker. On a base model? Sure, make people pay for the ability to find their way in an automated fashion across the country. In an almost top-trim truck, well, you’re just taking the piss.

Maybe my brain is wired a bit differently than Aaron’s father — that’s the guinea pig yardstick Aaron uses to figure out if a system is user-friendly or not — because GM’s system always confuses me. On top of that, the screen is so damn far away from the driver. If you need to do anything on the infotainment system while driving, you need to move ahead just short of unbuckling yourself to reach the screen.


Unfortunately, I didn’t get to test the Sierra with a load, but the unloaded drive gives a good impression of its capabilities. Effortless power. A smooth (for a pickup) ride. I just wish I was a bit more comfortable.

There’s something to be said for a big, American-style V-8. The Sierra, unlike the EcoBoost F-150, will put a 6.2-liter-sized grin on your face. This is about as close as you can get to a muscle car with a bed in the back. I’d even go far as to say this particular truck probably has more in common with the muscle cars of yesteryear than the modern muscle cars of today to their forebears. It’s unapologetic and without flash. Just a truck with a big engine that does exactly as its throaty lump advertises. The 6.2-liter L89 will completely embarrass that Craigslist Ferrari you’ve been eyeballing and be less of a basket case when it comes to repairs in the long run — not that you’d cross shop the two.

Yet, I cannot emphasize enough that this truck isn’t a workhorse. It might have the capability, but it’s too dear to be used around the cabbage patch. As a family hauler with the might to tow along a travel trailer or boat, however, it would feel right at home.

General Motors provided the vehicle and insurance for this review.

Mark Stevenson
Mark Stevenson

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  • Flipper35 Flipper35 on Aug 12, 2015

    Please tell me the animated gifs are not going to be part of the site! Road and Track litters their pages with these and it is horrible enough I can't stand to visit their site. One or two here and there is tolerable, but don't be putting them everywhere.

  • Dave M. Dave M. on Aug 13, 2015

    Good review. The Sierra is by far the best looking truck on the market IMO...but then again I also like the conservative look of the Titan. I get lost in a pickup truck...despite my physical size, I'm nervous Nellie driving that size bulk. I think Urban Cowboy started the whole Cowboy Cadillac pickup trend, at least here in Texas....funny how the Lincoln and Caddy trucks failed in the marketplace, but the $55k Fords, Chevys and Dodges they can't make enough of.

  • Tsarcasm No, Japan only. Life costs by Rank:#1 - House (150k+)#2 - Education (30k+)#3 - Automobile (30k+) why waste hard earned money in inferior crap => Korean, Chinese, and American cars are trash. a toyota or honda will last twice as long.
  • Tassos In the 90s we hired a former PhD student and friend of mine, who 'worked' at GM "Research" labs, to come work for us as a 'temp' lecturer and get paid extra. He had no objection from GM, came during the day (around 2 PM), two hours drive round trip, plus the 1.5 hour lecture, twice weekly. (basically he goofed off two entire afternoons out of the five) He told me they gave him a different model new car every month, everything (even gas) paid. Instead of him paying parking, I told him to give me the cars and I drove them for those 90 mins, did my shopping etc. Almost ALL sucked, except the Eldo coupe with the Northstar. That was a nice engine with plenty of power (by 90s standards). One time they gave him the accursed Caddy Catera, which was as fun driving as having sex with a fish, AND to make it worse, the driver's door handle broke and my friend told me GM had to pay an arm and a leg to fix it, needed to replace almost the whole damned door!
  • 3-On-The-Tree I only buy Toyota cars. But if the Chinese cars are cheap people will buy them. They don’t care about the above issues that were stated in this forum.
  • Tassos Ford models are like dumb Hollywood movies. The original is far better than their god damned sequels. This was true of the Mustang vs the II, AND the Capri vs its second gen, and their BEV PORKER atrocities many decades later
  • Jeff I would not buy a Chinese car with the current global situation with Taiwan and Ukraine but I believe eventually China will become the number 1 producer of vehicles globally. Lou brought up a valid point that much of the content of new vehicles has components made in China. Even many of the tires that are sold are made in China. Try buying a small appliance or electronics that are not made in China. Many of the electric motors that go in power reclining furniture are made in China. Many auto parts especially replacement parts are made in China.