As we have posted several times people are ignoring the ill effects of using E10 Gas.
Refer to other threads on the content about this and other test results

In this case a 2001 C5 Z06 located in Sac Ca in 90 degree weather.
Bob the owner had issues with lack of performance and lot more knock since feds mandated E10 gas be used
E10 use on left of results and E10 tune on right

As we see in testrun with E10 gas at 82 degrees that there was less WOT timing due to engine knock.
Knock on average was pulling over 3 degrees of timing, would be worse but the PCM was tuned in the past.

Notice the fuel injector duty cycle

Now with a custom tune to overcome use of E10 the PE/WOT tuning is higher, the knock overall average was zero.
Consider this testrun the weather was over 10 degrees hotter to 92 degrees yet now overall the engine is running better as you see by increased torque and HP.

Also notice though to solve the E10 issues via the tune that the injectors are commanded ON longer to overcome how poorly E10 produces power thus duty cycle is now 89% from 82% and that you see solved the 13.3 AFR to now a 12.5 AFR

Unknown to you, unless you monitor the engine on a regular basis with OBD scanner that long term damage happens with use of E10 with performance engines and in fact when E15 is mandated later this year the problem will be worse so it is a MUST to have a proper custom tune correct E10 issues.

Notice in lower graphs ( E10 top, Tuned for E10 bottom) how much knock E10 was causing and how much we reduced via the tune.