Quote:
Originally Posted by Epacy
Isn't HPI just BMW's name for DI?
RS4 engine does feature DI.
You are technically correct that the RS4 doesn't have HPI as that is BMW's implementation. But that was never being stated.
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No, RS4's DI is a socalled "first generation DI" whereas HPI is on of the first second generation DIs.
HPI is a spray-form DI (RS4's DI isn't spray-form) which has the advantage of extended lean-operation. Whereas FSI can save fuel (lean operation) only at low revs and quite low acceleration, the HPI stays in lean operation (=fuel saving) until about 4000rpm. As I said it's a totally new technology. Audi does not offer second generation DI to date.
So I am just as disappointed as Swamp that BMW didn't manage to feature HPI in M3's engine, but hopefully could clarify that it's nothing that Audi (RS4) "has" already.
Best regards, south