Rinaldo Rinolfi, director of the engine division at Fiat Research Center, talked with Automotive News Europe Chief Correspondent Luca Ciferri.
Will Euro 5 affect diesel costs?
It is difficult to be precise when the emission levels of Euro 5 have not been set yet, but I can discuss some basics. Suppose a 1.6-liter gasoline engine has a production cost of about E1,500. A Euro 4 equivalent diesel costs about E2,200, or almost 50 percent more. To clean such a diesel to the expected Euro 5 level will add another E400 to E500 between a particulate filter and engine management system tweaking. To get to Euro 6, the diesel would probably cost another E300 to E400.
So a Euro 6 diesel would cost E1,500 more, or double a gasoline engine?
Yes, and to get cleaner, the diesel will increase fuel consumption a bit.
Wouldnt gasoline engines cost more to meet Euro 5 and Euro 6?
No further tightening of gasoline engine emission limits is foreseen.
If production costs are half the retail price, diesels would be E3,000 more than gasoline engines?
Yes. Imagine how much you can add to a gasoline engine to make it better without a cost penalty.
What would need to be added?
Variable valve timing and a turbocharger, about E1,000 to the consumer. Such a gasoline engine will have torque and overall drivability close to the best diesels.
What about C02 emissions?
Today a diesel engine burns 30 percent less fuel and emits 20 percent less C02 than a comparable gasoline engine. Variable valve timing will cut gasoline fuel use by 10 to 12 percent. Turbocharging will save another 10 to 15 percent. So the gasoline engine would recoup most of the 30 percent fuel consumption penalty of now. The CO2 penalty will be fully recovered.
So a gasoline turbo engine for E2,000 less than a diesel, would burn 5 percent to 10 percent more fuel and emit the same CO2?
This is the most likely scenario.
So the gasoline engine will win.
Yes, and there is another good reason for it to prevail long-term. A gasoline engine can also burn alternative fuels such as natural gas or hydrogen. Unfortunately, even the most advanced diesel cannot.