Internal combustion engines power the vast majority of the cars and trucks on the road today. That’s not by any means a bad thing. While electrification of our cars dominates most of today’s headlines and resources, the internal combustion engine is still what moves most of us from one place to another.
These tried-and-true powerplants have evolved to meet modern requirements in ways that lend flexibility to current and future needs. A primary advantage to internal combustion is that engines can be powered by multiple fuel sources including gasoline, diesel, and an array of alternative fuels. That flexibility provides options moving forward.
Hybrid cars and trucks, in all their configurations, are a gateway to pure electric vehicle acceptance. Gasoline-electric hybrids rely on an efficient internal combustion engine to function. The hybrid envelope has expanded in recent times to include plugin models that can travel varying distances on pure electric power as well.
Automatic start-stop function is an important technology that makes internal combustion vehicles more city-friendly by shutting an engine off when stopped at a traffic light for more than a few seconds, eliminating unnecessary idling emissions. The engine remains off as long as a driver’s foot is on the brake pedal and the vehicle is not in motion. When the light changes, lifting off the brake immediately restarts the engine and you drive away.
Fuel economy improvements, lower carbon emissions, and overall emissions reductions are also being accomplished by other strategies. Among the most prominent is engine downsizing, which allows the use of smaller displacement engines boosted with power-adding technologies like turbocharging. The old adage, ‘there’s no replacement for displacement,’ is being successfully circumvented by smart engine downsizing.
Some elegant solutions are presenting themselves. One example is Nissan’s VC-Turbo, the world’s first variable compression production engine. Modifying engine compression ratio through sophisticated computer control allows adjusting compression in real time, optimizing efficiency and performance depending on driving conditions.
Another example is the introduction of Chevrolet’s next-generation Dynamic Fuel Management in Silverado 5.3-liter and 6.2-liter V-8 engines. This advanced technology optimizes power and fuel efficiency through cylinder deactivation, determining 80 times-per-second how many cylinders are actually needed for real-time driving needs, with the engine running on as little as a single cylinder to save fuel and decrease carbon emissions.
Gasoline engines have traditionally required a spark plug to ignite the fuel-air mixture in an engine’s combustion chamber to drive a piston. More thermally efficient diesel engines create ignition as a piston compresses the fuel-air mixture at high pressure, without a plug. So, what if you could combine the best of both worlds and make a gasoline engine work more like an efficient diesel?
It now appears the technology is ready for prime time and production. Mazda’s new SKYACTIV-X is set to become the world’s first production engine to use compression ignition in a commercially available gasoline engine. The automaker’s proprietary Spark Controlled Compression Ignition design provides considerable torque during acceleration, along with sharp engine response, improved fuel efficiency, and lower emissions.
The worldwide push toward electric vehicles has yielded some surprising consequences. One is an all-out effort to make combustion vehicles better and more competitive with the advancement and sharing of technologies across all platforms.
Is the internal combustion engine dead? Hardly. It just keeps getting better, more efficient, and technologically advanced as the years roll by.
The all-new 2019 Chevrolet Silverado 1500 pickup is lighter, more tech-laden, and a bit more aggressively styled but doesn’t look radically different than the previous versions. There are four new grille designs depending on the model. It comes in eight trim levels that include the high value Work Truck, Custom, and Custom Trailboss; the high-volume LT, RST, and LT Trailboss; and high feature LTZ and High Country. There are Regular, Double, and Crew Cabs; short and long beds, and rear-, four- and all-wheel drive models, depending on trim levels. Interesting aerodynamic touches are included like air curtains that improve efficiency.
Silverado offers plenty of powertrain choices. There’s an all-new 2.7-liter, four-cylinder turbo that features cylinder deactivation and stop/start for efficiency, plus a twin-scroll turbocharger for improved low-end response. It connects to an eight-speed automatic transmission and delivers an estimated 20 city/23 highway mpg. Rated at 310 horsepower and 348 lb-ft torque, this engine brings the Silverado a 2,280-pound payload rating and maximum tow rating of 7,200 pounds. A new 2.7-liter turbo engine replaces the naturally aspirated 4.3-liter V-6 in the Silverado LT and RST sport-truck. The 4.3-liter V-6 connected to a six-speed automatic transmission remains the base engine in other trim levels. A new 3.0-liter Duramax diesel paired with a 10-speed automatic and a stop-start system is coming in early 2019.
Furthering efficiency by an estimated 5 percent is the Silverado’s dynamic fuel management (DFM) technology that enables only those cylinders needed to deliver required power to come into play. DFM features 17 cylinder patterns that constantly determine how many cylinders are used to meet the torque demanded, making this determination 80 times per second to optimize efficiency and power delivery at all speeds. DFM is available on the optional 355-horsepower, 5.3-liter V-8 with an eight-speed automatic and 420-horsepower, 6.2-liter V-8 teamed with a 10-speed automatic. These V-8 engines also feature stop/start.
The Silverado's weight has been reduced by as much as 450 pounds, depending on the model, through the use of varying thicknesses of high-strength steel throughout and aluminum on some body panels. The Silverado offers the all-new Durabed cargo box that’s seven inches wider with greater volume for more hauling capacity. The crew cab’s wheelbase is four inches longer, overall length has increased by about 1.6 inches, and the truck is 1.2 inches wider. There’s also 2.5 inches greater rear-seat legroom. A two-inch suspension lift is a factory option. Pickups are often used for towing and Chevy makes this easier with the Silverado’s Advanced Trailering Package and Trailering Camera Package. A trailering app with theft alert and more is included.
