Don't count out the V-8 as a power plant for the future.
Many contend that only fewer cylinders will help automakers meet new federal fuel economy and emissions rules. But some manufacturers have doubled down on their bets that the V-8 engine will stay in the game.
In late April, General Motors Co. announced it was spending $893 million to upgrade North American factories to make new all-aluminum V-8s.
Dean Guard, GM's chief engineer and program manager for small-block V-8 engines, says the investment "speaks volumes on the fact that General Motors believes for the foreseeable future that the V-8s play a critical role in our gasoline engine lineup."
Guard said truck buyers in particular need the power and endurance of a V-8 to do the things trucks are meant to do, such as towing or hauling heavy cargo.
GM uses cylinder deactivation, which it calls Active Fuel Management, to improve V-8 efficiency by firing only four cylinders when engines are under light loads. The company also is using direct fuel injection, camshaft phasing and transmission advances to increase fuel efficiency in V-8s
Smaller, lighter V-8s
At recent auto shows, Ford showed off its 5.0-liter, 412-hp engine in the 2011 Mustang as an example of making a performance V-8 fuel-stingy. The EPA rates the car at 26 mpg on the highway.
"V-8s are going to be smaller, more powerful and weigh less, and they will be in vehicles where customers expect a V-8," said Ford spokesman Said Deep.
One example, he said, is Ford's latest diesel V-8, which is 160 pounds lighter than the previous diesel because it uses compacted graphite iron casting technology to make the engine block. In the case of the Mustang, Ford used dozens of technological advances, including a 32-valve design and twin independent variable cam timing.
Greg Johnson, Ford manager of North American Powerpacks, said the V-8 is not special in and of itself. The goal, he says, is to put an appropriate engine in each vehicle. The V-6 engine developed for the 2011 Mustang, for example, provides more than 300 hp but gets 31 mpg on the highway.
"The technology suite and the things we're going to do on a V-8 are not that drastically different than the things we're doing on our I-4s or V-6s," Johnson said.
Some in the industry say that for some applications, a V-8 may be not only the best choice for the customer but also the best choice for the environment. The turbo-boosted smaller engines meant to take the place of V-8s may not surpass advanced V-8s in real-world use, said David Champion, senior director of Consumer Reports' Automotive Test Division
"A turbo does well on the EPA cycle, but in real-world driving conditions, sometimes a larger-displacement engine gives almost the same fuel economy and much smoother driving," Champion said. "If you're into the turbo all the time, I'm not sure they're going to produce the fuel economy gains that are expected."
Brett Smith, a senior analyst at the Center for Automotive Research in Ann Arbor, Mich., said there certainly will be pressure for automakers to move to smaller six-, four- and even three-cylinder turbocharged engines in cars. For many trucks, performance cars and some luxury cars, though, the V-8 will be irreplaceable.
The advantage of a V-8 engine is not just its power but the heavily counterbalanced crankshaft and firing sequence that allow the engine to provide strong torque without harsh vibration and noise. Although smaller engines today are achieving horsepower ratings previously associated with V-8s, their output often comes at higher rpm levels and with a harsher driving experience.
"When you think about it, going back to the mid-1980s and early '90s, V-8s were getting about 250 hp," said Champion. "Now you've got normally aspirated V-6s getting 250 hp."
But while horsepower has gone up in smaller engines, so have the size and mass of light trucks.
"It takes all of the V-8 power to cruise them down the road," Champion said.
Champion said that combines with consumer preferences to tell him that for trucks, performance and luxury cars, the refinement of a V-8 is still going to be desired. Even while the majority of passenger cars and crossovers move toward smaller engines, he said, "I think there will be a few applications for the V-8.
(Source: Automotive News)