Diesel engines are the workhorses of the heavy-duty vehicle segment. Oil burners have abundant low-end torque which, coupled with inherent higher efficiency than gas engines, make them ideally suited for heavy hauling applications. But what if a turbocharged, high-compression, alcohol-fed, direct-injection engine could offer more power and emit less while lowering overall vehicle costs. Sounds intriguing, doesn't it?
Engine downsizing is considered an effective method to reduce emissions and improve fuel efficiency. The basic concept is simple: replace a larger engine with something that displaces less and, typically, packs a turbocharger to make up for any lost power. One impediment to engine downsizing is low-speed preignition (LSPI). Preignition occurs when the combustion chambers ignites prior to the spark event. This causes advanced combustion timing which can lead to heavy engine knock and catastrophic
Affordability as the watchword Tuesday as automotive engineers at the SAE World Congress discussed how to meet the new 2016 corporate average fuel economy standards. Automakers will have to get their fleets to an average of 34.1 miles per gallon (35.5 equivalent with other factors for the EPA CO2 limits). Most automakers are already well on their way to this level with their next-generation designs. However, to do it they will have to make improvements to virtually every model in the entire flee
2010 Audi S4 – Click above for high-res image gallery
In addition to the upcoming hybrid versions of the Panamera and Cayenne as well as an electric version of the 911, Porsche is believed to be preparing a low CO2 version of its next-generation Boxster. The new, lower-power variant would be meant to help Porsche meet upcoming European CO2 emissions limits.
Since the debut of the original BMW M3 in the mid-eighties, the high-performance editions of most of BMW models have garnered plenty of praise for their dynamic abilities. Unfortunately, over several generations, the M3, M5, and M6 have grown progressively porkier as they have grown more powerful. The engines have grown from the original four and six cylinder units to six, eight and then ten cylinder units.