Fleet work brings almost all every make my way, all vehicles under 2 years and most under 40,000mi. The one thing that I've seen across all makes (some worse than others) is intake valve coking on DI engines. Unfortunately I haven had a opportunity to check my SHO yet, but I did a engine replacement on a 2019 5.0L Mustang GT this week that runs the Duel Injection (DI +Port) and the proof is in the picture. This engine had 28,000 miles on it when it took it's last breath but take a look at the intake valve-absolutely spotless!
If any of you guys running methanol have picture stored of your intake valves or get a chance to in the future, please post up. I'd really like to see if the cleaning effect of the methanol is anywhere close to what I'm seeing on the new dual injection cars. I'm on the fence about adding methanol based on my daily driving needs, but if it's the only thing we have that's close to duel injection for our platform and if it's even close I'm in.