I have 8500 miles on my 2012 S10, & I usually run 87 octane with 10% ethanol, which is mid-grade in Colorado ... regular is 85 octane. Never pings, & I average 47-48 mpg whether commuting or riding in the high country (a little less in lower gears on dirt & gravel). I've run as low as 85 if higher wasn't available, & this engine doesn't seem to know the difference. My take? Ride ... & don't worry.