Delivering solid power and decent fuel economy across three engines, the 2015 GMC Sierra 1500 can be configured into anything from a daily driver to a trailer-pulling beast of a work truck.
Key Points
- With three engines, three cabs, and three boxes available, the 2015 GMC Sierra 1500 is easy to configure into your ideal full-size truck.
- GMC fans seeking a daily driver will want to go with the 4.3L V6, a Flex-fuel engine that will get 17/22 mpg, city/highway on regular fuel, or 12/15 on E85.
- The 355 horsepower 5.3L V8 is the ideal work truck in the lineup, towing over 11,000 pounds.
- At 420 horsepower, the 6.2L V8 only tows a thousand pounds over the 5.3L, so at this point, you might want to just upgrade to a 2500HD.
2015 Sierra’s 4.3L V6 Finds Middle Ground Between Towing Machine and Everyday Driver
The 2015 GMC Sierra 1500 starts out strong with an aluminum block 4.3L EcoTec3 V6. This will deliver 285 horsepower, 305 lb.-ft. of torque, and a towing capacity of up to 7,600 pounds
The Flex-fuel EcoTec3 engine aims for greater efficiency and performance through the use of direct injection, cylinder deactivation, and continuously variable valve timing. What all of this basically means is that everything the engine is doing, it’s doing on purpose. More efficient, effective oil delivery through VVT, and less wasted fuel thanks to selective fuel injection and cylinder deactivation. The end result is that, in 4WD, you get 17/22 miles to the gallon, city/highway, on regular gasoline, or 12/15 when using E85.
Gas tank size is dependent on your box options, at 26 gallons for the short and standard boxes, and 34 for the long box. That goes for all three engines.
The engine comes paired with a six-speed automatic transmission, plus StabiliTrak stability control and hill start assist, so if you’re looking for an off-road beast you’ll have no problem translating that 285 horsepower into real-world performance on rocks, mud, gravel, and sand.
The 4.3L can be matched with any box and cab setup you like.
355-horsepower 5.3L V8 is as Tough as Most Drivers will Ever Need Their Truck to be
With its two extra cylinders, the 5.3L EcoTec3 V8 can produce 355 horsepower and 383 lb.-ft. of torque, and tow up to 11,200 pounds.
The 5.3L uses all the same EcoTec3 technology you’ll find in the V6, so you can expect a pretty-decent mpg of 16/22 in 4WD mode. With E85, you’ll be going about 12/16 miles to the gallon.
Your other specs pretty much line up with the 4.3L: aluminum block, six-speed automatic transmission, StabiliTrak, hill start assist. It’s effectively the same engine as the V6, just a lot more of it.
As with the 4.3L, you can match the 5.3L up with any cab and with any box.
2015 Sierra 1500’s 420-horsepower 6.2L V8 might be too Big an Upgrade for a Half-ton Chassis
The top-shelf 6.2L EcoTec3 V8 cranks out a whopping 420 horsepower and 460 lb.-ft. of torque. Utilizing the same EcoTec3 optimization tech as the other engines, the fuel economy doesn’t even take that big a hit, at 15/21 miles to the gallon, city/highway, in 4WD mode.
If you’re looking for the best towing machine in the lineup, this is it, topping out at 12,000 pounds. And that’s just because the chassis can only take so much. The 6.0L version found in the 2500HD can pull more than 14,000 pounds.
The 6.2L is paired with basically the same features as the other engines. StabiliTrak, hill start assist, etc. But the 6.2L gets an eight-speed automatic transmission.
The 6.2L V8 will pair with any setup except for the regular cab or the long box.
Keep an Eye out for Smoke Under the Hood in 4.3L and 5.3L Engines
The 2015 GMC Sierra 1500 has had 20 recalls since its launch, which is a lot. But only one of these recalls relates directly to the engine. Two more had to do with leaks in the fuel supply system, but those recalls affected barely more than 50 units each.
The recall to be concerned with is the one issued in January of 2014 for 325,213 2014 and 2015 GM vehicles with 4.3L and 5.3L engines. This recall had to do with components in the engine’s exhaust system which had a tendency to overheat and melt plastic parts under the hood and potentially cause an engine fire.
Thankfully, this recall was issued very early on for the 2015 Sierras, so most units had already been corrected before they even hit the market.
The 4.3L V6 and 5.3L V8 Each Serve their Purpose Beautifully, but the 6.2L might be more Power than You Need in a 1500
Truth be told, all three of the 2015 Sierra 1500’s engines are fine choices.
The 4.3L V6 is the best daily driver by a long shot. Most drivers don’t have to pull more than 7,000 pounds on a regular basis, so the V6 should be strong enough to handle more jobs than not, it’ll save you a bundle on gas over the years, and it frees you up to go with any box and cab combo you like.
With the 5.3L V8, you get a tremendous power upgrade for dedicated work trucks, but it’s much more specialized. If your truck is your second vehicle, get the 5.3L. If it’s your primary vehicle, stick with the V6.
The 6.2L is awesome, but in a 1500 chassis, it doesn’t offer enough of a power upgrade over the 5.3L to be worth the extra gas money. And it locks you out of the long box, so you might not be able to do as much hauling as you like. It basically leaves you wanting for a 2500HD, so at that point, you might as well just upgrade to a Heavy Duty.
Photos: GMC
