Just bought the new Chevy 2500HD with 6.0L gas ... and wondering what you guys run for octane. And why you choose it? -- The 'why' is important too ... because it's not just about mpg, it's about ...
87 is all that is required and will not get higher performance or use less fuel for higher octane alone. But E10/E15 is very common across the USA. Some stations do not use E10/E15 for higher octane fuels, which does tend to decrease fuel consumption.
