What is arguably the best powertrain combination in terms of efficiency for a standard hybrid vehicle? Many would suggest that the diesel engine paired with the hybrid components would make for the most efficient hybrid setup. Few argue that a diesel would be capable of returning better mileage in the hybrid segment than a gasoline engine vehicle, but their are significant hurdles and drawbacks that prevent most manufacturers from pursing this setup.
As GM engineer Mauricio Cisternino said of the diesel hybrid setup in an interview with Autocar, "If you want the best fuel consumption, you have to go with the diesel-electric hybrid. Hybrids are most efficient in the city, while diesels are best for motorways."
The main hurdle to overcome is cost. It is estimated by some that a diesel hybrid would cost at least $4,000 more than a gasoline powered hybrid setup. This chunk of change is significant considering that hybrid buyers already pay a premium over standard versions of vehicles. A hybrid average about $5,000 over the gasoline version, add the $4,000 for a diesel engine and your looking at a $9,000 increase in price. This added cost will likely drive off buyers. Though cost is a major concern, complexities in implementing diesel and hybrid technology are certainly another concern.
According to Autocar, General Motors is currently developing the diesel hybrid setup described above and this setup will only command a premium of about $1,400 over a traditional gasoline hybrid. How can they achieve this? Who knows.
According to Maurizio Cisternino who is GM of Europe's advanced technology chief engineer, General Motors aims to bring the diesel hybrid to market in an Opel or Vauxhall product by 2012 and they are targeting a premium of only $1,400 over conventional hybrids.
If GM can accomplish this, it would be a great achievement. The diesel engine likely to see use in upcoming diesel hybrid is the company's all new 1.6 liter turbodiesel, 4 cylinder. This engine's electronic controller is specifically designed to be compatible with hybrid setups.
Something else to ponder. If GM can successfully integrate the diesel and hybrid technology into a single package with only a $1,400 price increase, the diesel engine could potentially be integrated into the Voltec powertrain as a possible upgrade.