So far I know of two companies that use this: Volkswagen and GM. Basically, in the “Bang” cycle, the fuel is injected and immediately combusted. Why is this useful you ask? Well, on turbocharged motors, instead of investing quality into the fuel tab, lowering the compression, or lowering the A:F mixture, you can squeeze that air just a bit more with SIDI since it’s capable of higher compression.
I’m not asking if you, the dev team, can implement this now, but if it can be in at one point at all. It’s kind of like if you guys were to do the diesel DLC, a lot of people will ask for Indirect Injection in order to remake or compete with diesels from the pre-2000’s. Just food for thought. 
Do you mean compression ignition direct injection, because the current direct injection is Spark Ignition Direct Injection.
That sounds exactly like it. That’s odd if the current Direct Injection is the SIDI, because I can’t pull a 10:1 compression ratio with 12.5 psi and a proper, economical turbocharger build - which Chevrolet and Volkswagen both pull off with even higher boost (~13-14 psi).
Yeah, there might be a bit more work required there on our part, turbos in general need some revising.
Direct injection does allow a bunch more compression and boost ingame though, just don’t forget you’ll need to run it reasonably rich under power (which may not actually impact total fuel economy too badly once it’s in a car)
