[geaux_tigerss]

I feel like E85 is a no brainer first mod if you are willing to tune the car and have an E85 station near you. Kind of like headers and tune were a no brainer first mod for 5th gen SS cars.

Pros:
Cheap. sensor: $215, tune: $700 (bit of +/- here)
HP Gain of 30-40 whp.
Tailpipes don't turn black.
Smells less bad than gasoline if you have no cats.
Cheaper $/mile than gasoline.

Cons:
Bad fuel mileage - I get 23-24 on the highway, usually 15 or so around town daily drive average.
Literally no other cons.

I've seen oldman say it a few times and I have to agree. Best "stage 1" round of mods is primary cat delete, E85 sensor, factory ported intake manifold, and tune. You're looking at 60-70 whp for roughly $1,400. You can go a hair further with full bolt ons (throttle body, cold air intake, under drive pulley, long tube headers), but you hit diminishing returns in a hurry.

Gm should have enabled the flex fuel from the factory and added the sensor.