Fuel-Efficient Power, the Change Away From the V8
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Back in the day, what we know now as sports cars were equipped with high-displacement fuel-drinking machines. All that has changed now as companies strive to improve their car’s performance while trying to save mother earth as well. Companies have put their focus towards efficiency of an engine, while trying to get the most power using the least amount of gas.
This change has taken place throughout the entirety of car manufacturers, including BMW, Audi, Mercedes-Benz, Ford, and even Ferrari. Most of the JDM (Japanese domestic market) cars such as Subaru, and Mitsubishi have always used low displacement engines that produce good numbers on the dyno (device used to measure an engine’s horsepower/torque), while also being extremely fuel-efficient. Most of this comes from the use of turbochargers and superchargers.
A turbocharger, or more frequently called turbo, is defined as a gas compressor used for forced-inductionof an internal combustion engine. In English, what this means is a turbo forces more air into the combustion chamber (where the explosions that power the engine take place), therefore using less gas and creating more power. A supercharger is essentially the same thing, except that the air is forced in from a belt, shaft, gear, etc. A naturally aspirated (no turbo or supercharger) vehicle is usually around 25% less efficient than a forced induction vehicle. Although this all depends on the boost of the turbo, type of turbo, and many more things to determine exactly.
BMW’s relatively new 335i uses a twin turbo 3 liter inline 6 cylinder engine to produce 300 hp and 300 ft/lbs of torque. BMW’s M3 has a 4 liter V8 producing 414 hp and 295 ft/lbs of torque. A tuned 335i (software tune) puts down near 400 hp and 430 ft/lbs of torque. The 335 averages 22 MPG while the M3 averages 17 MPG. A tuned 335 would average the same if not better mileage, and be faster than the M3. If BMW used the 3 liter engine like in the 335 and tuned it, they could easily make it faster than the new M3.
A prime example of this change that has taken place is found in the new 2009 Audi S4 (B8 model line). The B7 and B6 (2003-2008 models) both used Audi’s 4.2 liter naturally aspirated V8, which produced around 350 hp and averaged around 16 mpg. Audi announced that the new S4 will come equipped with Audi’s new 3.0T as they call it. Which is essentially a supercharged 3.0 liter V6 producing 360 hp and averaging around 24 mpg. That’s 10 more horsepower and loads of torque more than the previous V8, while also being MUCH more fuel-efficient. Many Audi enthusiasts say they will miss the growl of the B6’s and B7’s V8, but will not miss the horrible gas mileage associated with the V8.
You wouldn’t expect owners buying $200,000+ Ferrari’s to be worrisome about gas mileage of their beasts, but their manufacturers definitely are. Rather it be for the economy or for the earth, Ferrari has started innovating to new ways to combine fuel economy, with power. Their plans include improvements in Aerodynamics, weight reduction, forced induction, rolling resistance, and their transmissions. Ferrari announced that they plan on lowering the idle speed to 700 rpm’s, using 20% bioethanol, and including more gears in their transmissions in order to improve mileage.
It’s obvious that the change from the V8/V10/V12 will never fully happen. Companies such as Bentley will never put a 6-cylinder engine in the continental GT because that engine just doesn’t fit that car. However in cars like the Audi S4 and the BMW M3, which are both sports sedans and daily drivers, a fuel efficient 6 cylinder is definitely in their near future. The future is not in the V8, it’s in forced induction and taller gears.
