Quote:
Originally Posted by redpoint5
I get the impression that turbo charging a smaller engine is no longer the fuel efficient way. Perhaps due to the lower compression ratio?
|
Quote:
Originally Posted by redpoint5
So these turbo engine vehicles might get better fuel economy in stop and go driving, but worse in steady cruise?
I know Toyota gave the Gen III and IV Prius a larger displacement than the Gen I and II. Displacement must not be such a huge economy penalty as long as you can keep the engine near the BSFC sweet spot.
|
I don't believe everything this guy says. But he seems to have a good point. Traditionally turbocharged engines are made with lower CR's, use a lot more high load enrichment and retard the timing much more than N/A engines. The result is worse fuel economy. But if other forms of knock control are done properly, like cooled EGR, a turbocharged engine can theoretically get good fuel mileage.
[YouTube]