2015 GMC Sierra 1500
2015 GMC Sierra 1500 pickup trucks are available in base, SLE, SLT and Denali denotations. Regular, double and crew are the three cab choices offered for the Sierra half-ton, with the Denali only being available as a four-dour crew cab. The standard bed length for this year is 6.5 ft, with an 8 ft long box and a 5.75 ft short box able to be optioned on select cab configurations. In terms of motors, the same EcoTec3 family powers the 2015 Sierra. The base all aluminum V6 produces 295 horsepower and 305 lb-ft of torque with the tried-and-true 5.3L rated at 355 horsepower and 383 lb-ft of torque. A 6.2L V8, making 420 horsepower and 460 lb-ft, is standard on the Denali and available as an upgrade on SLE and SLT trucks. Changes from the year prior include 4G LTE connectivity, new available spray-on bed liner and magnetic ride control (exclusive to Denali).
Big Exhaust Gains
The LT series of motors has always been very responsive to exhaust upgrades, and in the case of the 5.3L and 6.2L V8 engines on the 2015 Sierra, a complete header and mid-pipe upgrade can net some serious power gains. A performance long-tube header matched to a high-flow mid-pipe can easily net gains in the neighborhood of 20-30 horsepower.
- Improve scavenging
- Higher flow capacity
- Net 20-30 horsepower
The big choice when selecting a header and mid-pipe kit is what size header to get. The two main sizes offered for the 5.3L and 6.2L powered 2015 half-ton pickups is 1-3/4 and 1-7/8. These measurements refer to the diameter of the primary tube of the exhaust header, and despite only being a difference of 1/8, can have vastly different performance characteristics. Larger headers have more flow capacity, but sometimes this comes at the expense exhaust velocity, which is also an important variable. In this case, 1-3/4 headers are generally better suited to the exhaust port size of the engine and produce strong low-end and mid-range power. Using a 1-7/8 primary tube header will up the flow capacity but decrease the flow velocity. You'll notice better top end gains with the bigger header but sacrifice some low end torque in the process. When it comes to the mid-pipe, all feature a Y-connection (in order to made with the rest of the factory exhaust system). Mid-pipes labeled as 'off-road' likely don't have any catalytic converters, which will be the highest performing option (least restrictive) but not actually legal to use on the road. The good news is the high flow catalytic converters incorporated into the mid-pipes really aren't that restrictive and will keep your truck emissions compliant while still performing to a high degree.
Bull bars, not only do they create a very bold and muscular appearance, are highly functional pieces of equipment that can help a 2015 Sierra pickup work better on and off the road. Initially built to provide the front end with an additional layer of protection, modern day bull bars maintain this primary function but have also a ton of added functionality like built-in winch trays and pre-drilled LED light mounts. Traditional bull bar design uses tubular steel formed to create a strong bar with a smooth appearance. That said, with the more chiseled and angular look of the 2015 GMC Sierra, aftermarket manufacturers are beginning to incorporate similar design cues into their bull bars, with more and more using hard angles and rectangular steel in their construction. Regardless of appearance, it is important that any bull bar you choose be durable, which largely depends on the material and how it is finished. Mild steel is the most common material used in bull bars, due to its good strength and low cost. The one downside is its susceptibility to rust and corrosion and therefore must be properly sealed from the elements. Stainless steel is another material often found in the bull bars, generally using a 304 grade. With increased nickel and chromium content than mild steel, T304 stainless is stronger and exhibits much better natural anti-rust and anti-corrosion properties. In fact, it is usually left unpainted and is just polished to provide a bright mirror-like finish.