Volkswagen Dumps Non-Turbocharged Gasoline Engines
By 2017 or so, Volkswagen (VW) and maybe Ford, will send the non-turbocharged, naturally aspirated car engine into obsolescence. Since 2005, VW has been comparing data between its turbocharged and non-turbocharged engines and has decided that the best efficiency is with the turbo diesel and gas engines.
It will replace its 2.5 liter and two six cylinder engines with turbocharged versions. The MPG differences are significant and that is what customers want. For instance, even a 2005 VW Jetta or Passat diesel still is way better than many of new 2013-14 non-turbo engines. A 2005 Jetta TDI (diesel) is clean and easily gets 30-32 MPG in the city and a whopping 40-45 MPG on the highway for its 1.9 liter engine. A new VW Jetta with no turbo manages only 26 MPG in city and 32 Hwy. So, as a consumer, which car would you buy if both were similar but for the engines?
I can personally attest to the 2005 MPG. I had an 2005 Subaru Outback non-turbo and got only 25 MPG on the highway. That is quite a difference from 40-45! Of course diesel is a bit more expensive, but the car easily competes with any hybrid in the MPG category.
Like all turbos, even in a 1991 Mercury Capri XR2, the turbo is only on when needed in certain ranges of acceleration, it is not always on. Actually, turbos have usually provided more horsepower and better fuel economy, even the 1966 Chevy Corvair Corsa (rear engine) had a turbo that provide 180 hp boost for highway driving or passing.
The non-turbo engines are less fuel efficient because they have the power built in, always present, even at low speeds. The turbos are only activated when driving requires it and when it is not, the engine runs without the turbo, consuming less fuel.
Who knows, as time goes on, maybe diesel engines in cars will be phased out, but right now, diesel engines are more efficient than gas.