Active Fuel Management
Fuel efficiency in vehicles is of utmost importance and the need for improved fuel efficiency grows each day. The most obvious reason for car manufacturers to really focus upon improved fuel economy is the growing cost of fuel; gasoline and diesel are nonrenewable forms of fuel and are understandably getting more and more expensive with their ever growing use in automobiles, industries and so on. Another important reason for improving fuel efficiency is reducing the cost to environment that is caused by the emissions that are produced by automobiles due to the combustion of fuel.
GM, being ever aware of the need for more fuel efficient cars, has installed a very effective method of improving fuel economy; Active Fuel Management. Active Fuel Management, also known as cylinder deactivation, is a rather ingenious idea of using as many cylinders as are needed. This is perhaps a rather simple explanation of the system. An explanation with a bit more detail is that while at cruising speeds, which do not require all 8 cylinders in order to maintain speed, fuel delivery to four of eight cylinders is deactivated (thus the name cylinder deactivation) and the valve lifters are collapsed to reduce pumping losses and hence improves fuel efficiency (essentially turning your truck into a 4 cylinder in V configuration). Once the driver presses the gas paddle again, all the cylinders fire up and the car accelerates. According to EPA the Active Fuel Management system improves fuel economy by 5.5% to 7.5%. In terms of miles per gallon, GM trucks average 15 mpg in the city and 21 mpg on the high way which is quite impressive.
Compared to GM, Ford has its EcoBoost engines which are basically turbo charged engines with direct injection that have power output comparable to bigger naturally aspirated engines (big V8 engines) thanks to the turbochargers and give better mileage. The Ford F-150 with the EcoBoost twin turbocharged engine is fairly good at hauling and towing and gives really good fuel economy. The 2013 Ram is also making use of an optional V6 with an 8 automatic speed gearbox that helps improve economy greatly. However, if you want the towing capability of a big V8 that is fuel efficient as well, GM has the solution for you! GM will have active fuel management in its new small block v8 for its 2014 Silverado and Sierra.