Chevrolet makes Stop/Start standard on base 4-cylinder in 2015 Impala; 5% improvement in city fuel economy

Stop/start technology will be standard on the 2015 Impala base 2.5-liter ECOTEC engine, an addition that improves the vehicle’s city fuel economy by nearly 5%, or one mile per gallon. The Impala comes standard with a four-cylinder engine, which currently accounts for more than 30% of Impala retail sales.

For the 2015 model year, the Impala will be available with two powertrains, a standard 2.5L engine with stop/start, and a premium 3.6L six-cylinder engine. The Impala with the 3.6L V-6 engine will not include stop/start technology.

Stop/start shuts down the engine in certain driving conditions to reduce fuel consumption. The technology is becoming more prevalent worldwide. A recent report from Navigant Research predicted worldwide sales of vehicles with stop/start technology (SSVs) will grow from 8.8 million in 2013 to 55.4 million in 2022.

The 2.5L Impala with stop/start yields an EPA-estimated fuel economy of 22 mpg city (10.7 l/100 km), 31 mpg (7.6 l/100 km) for the highway and 25 mpg (9.4 l/100 km) combined.

The Impala becomes the second vehicle in Chevrolet’s US. lineup to feature stop/start technology, following the segment-first standard inclusion in the 2014 Malibu introduced late last year. The technology helps improve the Malibu’s city fuel economy by 14%.

Chevrolet engineers developed the stop/start in the Impala from extensive experience with GM’s eAssist system and the accompanying algorithms that allow engines to engage and disengage subtly.

Stop/start system customer research indicates they want the engine to start up as quickly and smoothly as possible after a stop.

—Mark Meyers, Chevrolet Global Vehicle Performance manager

During the development of this technology, a team of software engineers was created. The Center for Excellence focuses on advancing stop/start technology and making its operation seamless to the customer.

A big challenge for the team was overcoming “change-of-mind events,” instances in which the driver begins to stop, but then quickly accelerates. The algorithms adapt the system so the starter can fire even if the engine did not fully shut off.

The software also prevents the system from engaging if the car does not reach 6 mph (10 km/h) since its last start—a feature for stop-and-go-driving conditions. The system also considers cabin temperature, humidity, battery charge and other factors when deciding if the engine should come to a stop.

Hardware revisions also have been made. The noise and vibration team worked closely with drivetrain engineers to revise motor mounts to provide the greatest isolation possible from the cabin. Additionally, the team included a larger heavy-duty starter motor to assist with the additional ignition cycles.

The 2015 Impala goes on sale this summer with a suggested starting price of $27,735 for the 4-cylinder LS model, and $30,960 for the 6-cylinder LT model. These include an $825 destination charge, but exclude tax, title, license and dealer fees.

New 3-cylinder, 1.0-liter Ford EcoBoost engine to debut in European Focus range

Ford has confirmed that the first production applications for the new 1.0-liter, 3-cylinder EcoBoost engine will be three models in the European product range: first the Focus, followed by C-MAX and the all-new Ford B-MAX. The new 1.0-liter engine is the latest addition to Ford’s global family of EcoBoost engines, which currently range in capacity from 1.6 to 3.5 liters globally. Downsized EcoBoost engines feature turbocharging, direct injection and other technologies and replace larger engines with no loss of performance and with lower fuel consumption.

Ford will introduce two versions of the 1.0-liter engine in the Focus in Europe in early 2012 with 100 PS (99 hp, 74 kW) and 120 PS (118 hp, 88 kW) and 5-speed and 6-speed manual transmissions respectively. Ultimately, this all-new engine will be made available in Ford models in North America, China and in other regions.

With its 1.0-liter capacity, the 3-cylinder EcoBoost engine will be the smallest engine currently produced by Ford. Yet, despite its small capacity and proportions, the design delivers power and performance to rival a traditional 1.6-liter gasoline engine while emitting less than 120g/km CO₂ in the Focus.

Developed at Ford’s Dunton Technical Centre in the UK, this direct-injected EcoBoost engine features a new compact, high performance turbocharger design. The extremely fast response of the turbocharger and its ability to reach nearly 250,000 rpm results in virtually no turbo lag and peak torque of 170 N·m (125 lb-ft) from 1,300-4,500 rpm in the 120 PS variant.

The new EcoBoost engine also features an exhaust manifold cast into the cylinder head, which lowers the temperature of the exhaust gases and in turn enables the engine to run with the optimum fuel-to-air ratio across a wider rev band.

An advanced “split cooling” system reduces fuel consumption by warming the engine more quickly and—unlike the larger EcoBoost engines—cast iron has been selected for the block, reducing the amount of energy needed for warm-up by up to 50% compared with aluminum.

Intelligent ancillaries such as a variable air-conditioning compressor and oil pump also reduce parasitic loads on the engine, while special coatings for engine components and intricate development of engine geometry result in minimal frictional losses.

Ford Auto-Start-Stop, Active Grille Shutter and Ford Smart Regenerative Charging will also be available as part of the Focus and C-MAX 1.0-liter EcoBoost package.

Like its larger capacity siblings, the 1.0-liter EcoBoost engine will use Ti-VCT twin variable camshaft timing to further improve performance and economy. Ford has also employed an all-new camshaft actuator to speed up response times without sacrificing durability.

In the all-new 1.0-liter Ford EcoBoost engine, the emphasis in development has been on delivering both smooth and refined performance. Engine refinement is improved thanks to an innovative design that immerses the two main engine drive belts in oil, resulting in quieter and more efficient running but with the durability of a chain. Careful attention has also been paid to mitigating the natural vibrations of the 3-cylinder design.

Rather than employ the traditional method of adding energy-draining balancer shafts, Ford engineers have deliberately “unbalanced” the flywheel and pulley to offset the engine configuration. Ford believes these innovations combined with optimized engine mounts will deliver a refined performance feel perfected during 720,000 km of tests,including 360,000 km of durability trials and 10,000 km of environmental testing.

Further technical details of the new Ford EcoBoost 1.0-liter engine will be provided closer to market launch across Europe in early 2012.

Source: Green Car Congress