New car engines boast improved efficiency, performance at the same time

Electric concept cars seem to steal the spotlight at auto shows these days, with their flashy futuristic looks and promises of amazing battery range. And many if not most cars will get some form of electric power in the coming years.

But conventional engines are far from dead; they're squeezing more from each gallon of fuel while providing increased power. And these engines will help with the transition to electric power, as many form an integral portion of a gas-electric hybrid drive system.

A great example of engine tech comes from Volvo. A 2.0 liter four-cylinder engine now powers all of its vehicles, from the trim S60 sedan to the large XC90 SUV. One engine, offering three levels of power, thanks to three flavors of technology. The T5 version makes 250 horsepower via turbocharging. For the T6, Volvo combines a turbocharger and a supercharger, for an output of 316 horsepower. And in T8 models, hybrid electric drive is added, and the total horsepower goes up to a whopping 400. This is from a relatively small engine size that was only suitable for economy cars not all that long ago.

Even high performance cars are going on an engine size diet. The new Mercedes-Benz CLS 53 AMG, for example. The performance model of the CLS used to have thumping V8 power. But Mercedes-Benz's new six-cylinder AMG engine - with a 48-volt mild-hybrid system - makes 429 horsepower from only 3.0 liters. And yes, the car still provides those legendary AMG driving thrills, along with a 27% improvement in fuel efficiency over the previous V8 AMG model. At a base price of about $80,000, however, most buyers of this car are probably not concerned with fuel costs. But they might be interested in efficiency for environmental reasons.

Electronics get a lot of the credit for these more efficient engines. As on-board engine management systems have advanced, so has the potential for performance along with efficiency. But in some cases, mechanical ingenuity is also playing a part.

The optional 2.0 liter VC-Turbo engine in Nissan's 2019 Altima brings a new trick: variable compression. Thanks to a clever knee-joint type assembly on the engine's internal connecting rods, the engine is able to vary the compression ratio based on demand, in a nanosecond. So, the same engine can produce great fuel economy, or up to 248 horsepower, seamlessly, as you drive. Expect Nissan to add this new VC Turbo engine to more models in the near future. For right now, it's available on SR and Platinum trim levels of the Altima, with prices ranging between $30,000 and $35,000 before options.