This probably isn't the long run, but my 2016 EXL has 38,000 flawless miles on it. I have used top tier unleaded gas in it over the lifetime of the vehicle.Now that it's been a few years since the new engine was introduced, I imagine someone has hit >100k miles.
I'm curious to find out if carbon buildup from the direct injection has been an issue over the long run.
Look up DI carbon build up. It’s the nature of the technology. Fuel isn’t sprayed directly on top of the valves like fuel injected engines. Instead it’s sprayed right into the combustion chamber. So the tops of the valves are prone to carbon build up. This is why using a quality top tier fuel is a must with DI.155,000 miles for me.. just Transmission issues.. Changing timing belt tomorrow. No one brought it up at the 100k service.. Sounds like one of my tensioners is making noise.. That happens though. they bearings go bad at some point.
Why would their be carbon build up from direct injection? Isn't that a better atomization and more efficient method of fuel delivery? So it is less likely to run rich? I've always had carbon build up from a rich condition or oil getting into the fuel delivery system.