It's a shame but I don't think I'll ever see digital systems in widespread use in my lifetime. Full Authority Digital Engine Control (FADEC) systems are out th

It's a shame but I don't think I'll ever see digital systems in widespread use in my lifetime. Full Authority Digital Engine Control (FADEC) systems are out there but they're generally not trusted. People understand mags and vacuum pumps and the peace of mind it brings to know you can lose your entire electrical system and still be flying. Most of the FADEC systems have dual alternators, dual controllers and dual sensors, but people still don't run them very often. Probably the most popular one I know of is in the Rotorway Exec series helis. SDS also sells a (non-redundant) EFI system that's used in a couple of aviation applications. My dad is using a SDS system in his Jenny. You also can't run a modern closed loop EFI system because of 100LL (avgas). The lead in it will destroy an oxygen sensor. So you're still stuck with a mixture lever in most cases. And that's just the experimental crowd. The cost of certifying an EFI engine into an existing airframe would make a retrofit cost prohibitive. Most people won't spend an additional $20k at overhaul time to add fuel injection and digital ignition. It would take a bunch of hours at +20% efficiency to make that back. A couple years ago I heard about a company selling a modern ignition system packaged into a mag. The idea was to replace one mag with the digital ignition and leave one mag as a safe backup. I don't know what happened to them. Last I heard they were selling units and working on certification for the Lycoming O-320/O-360 and Continental O-300 engines. Also, I just looked up the guy in the article. He sells his digital ignition systems for around $2k. He's managed to get a STC for a heli, so that's some progress in the right direction.