The 2016 Chevrolet Cruze is powered by GM’s new family of Ecotec small-displacement engines, featuring a modular architecture that is easier to build and adaptable to global markets.
In North America, the Cruze is offered with a new Ecotec 1.4-liter turbocharged engine that features direct injection to help offer a GM-estimated 7.06l/100km (40mpg) on the highway with an available 6-speed automatic transmission. Standard stop/start technology contributes to efficiency in stop-and-go driving.
The new 1.4-liter turbo is SAE-certified at 155ps and 240Nm of torque, using regular unleaded fuel (RON 91). It will be offered in additional markets, along with a 1.5-liter naturally aspirated variant rated at an estimated 115ps and 146Nm of torque. The 1.5-liter will be matched with a 5-speed manual transmission.
“The new Ecotec family is a globally designed and manufactured engine designed to offer class-leading performance, efficiency and refinement in a wide variety of applications around the world,” says Dan Nicholson, vice president, GM Global Powertrain. “Each variant is designed for a specific application or local market, but all share design, performance and refinement traits that make the new architecture one of the most adaptable in the industry.”
The new Ecotec 1.4-liter turbo is matched with a standard 6-speed manual or available with GM’s new Hydra-Matic 6T35 6-speed automatic transmission – offering, GM claims, the strength of the larger 6T40 transmission in a smaller, lighter package that enhances the Cruze’s efficiency.
Chevrolet will add a new clean diesel engine to the line-up in 2017, featuring a B20-capable 1.6-liter diesel already proven in Europe and other global markets.
“The current Cruze diesel has garnered a loyal following among customers seeking strong, clean and efficient diesel,” says Nicholson. “The next Cruze diesel will take those attributes to the next level with the very latest technology, offering what we expect will be the premier small-car diesel package in North America. It affirms GM’s commitment to offer diesel engines as an alternative propulsion choice for cars in North America and specifically targets the German dominance in the segment.”
The new Ecotec small-displacement engine family featured in the Cruze represents a clean-sheet design and engineering process, leveraging the diverse experience of GM’s global resources. Modularity in parts – such as four-cylinder and three-cylinder blocks – that share bore spacing, bore diameter, liners and other dimensions, reduces complexity and enhances value.
The new engines feature an aluminum cylinder block and head, which helps reduce the Cruze’s overall mass to enhance performance and efficiency. They also feature an integrated aluminum cylinder head/exhaust manifold, which further reduces weight – an attribute that contributes to increased vehicle efficiency and a more favorable front-to-rear weight balance, for a more responsive driving experience.
Computer simulation and modeling were instrumental in developing the new engine family. GM’s engineers at powertrain centers around the globe were able to design and test parts virtually and immediately share the results with their colleagues.
In addition to designing the engines’ basic components electronically, friction, temperature, emissions, efficiency and other performance attributes were modeled and simulated multiple times to make the most of performance before the first physical components were produced. Modeling also helped cylinder block design and other components with structural and acoustic considerations.
“By doing the majority of the development with math data, the time to design, validate and bring to market an all-new engine family was greatly reduced,” says Tom Sutter, Ecotec global chief engineer.
A lightweight, high-pressure die-cast aluminum block is the engines’ foundation, matched with an aluminum bedplate that enhances strength and helps reduce vibration. The high-pressure casting method produces a more dimensionally accurate block that requires fewer machining operations than conventional sand-cast blocks.
For structural stiffness, the block has cast-in-place iron cylinder liners. The bedplate bulkheads also contain cast-in, nodular iron inserts for localized structural stiffness. A die-cast aluminum oil pan contributes additional structural strength.
Each engine features 74mm cylinder bores and comparatively long piston stroke lengths that contribute to their strong torque. The 1.4-liter has an 81.3mm stroke and the 1.5-liter version has an 86.6mm stroke.
Bay-to-bay breathing, which enhances performance through reduced windage in the crankcase, is enabled through holes cast in the top of the bulkheads and through passages cast where the block and bedplate meet. Cast passages for oil and blow-by management and a 4mm wall thickness combine to reduce the overall weight of the block assembly, enhancing vehicle performance and efficiency.
A durable steel crankshaft is used with the Ecotec 1.4-liter turbo and Ecotec 1.5-liter for strength and reduced engine vibration.
Powder-metal steel connecting rods and hypereutectic-alloy aluminum pistons are tough and contribute to quietness. They are used with low-tension rings that reduce friction, which contributes to greater efficiency.
A variable-flow oiling system helps maximize fuel efficiency. The crankshaft-driven oil pump matches the oil supply to the engine load, changing its capacity based on the engine’s demand for oil – eliminating energy wasted to pump oil that is not required for proper engine operation.
Piston-cooling oil jets minimize piston temperatures – helping to optimize performance, refinement, efficiency and emissions.
The cylinder head has a water-cooled exhaust manifold integrated within the aluminum casting. Its single-piece design promotes quicker engine warm-up, which contributes to better emissions performance. It also enhances durability by eliminating the need for gasket sealing around the exhaust ports, as well as offering under-hood packaging advantages.
Dual overhead camshafts, operating four valves per cylinder with low-friction, hydraulic roller finger followers, are hollow in sections to save weight, and are driven by a timing chain with automatic hydraulic tensioning. Aluminum cam phasers enable variable timing for the opening and closing of the inlet and exhaust valves, making the most of fuel consumption and performance under a wide variety of engine load conditions.
June 25, 2015