I have been running E85 in my 2019 JCW and it is great. It is cheaper than any "OCTANE BOOST" bottles and it has caused no problems.

11.5 gallon tank...some people run 3.5 gallons but I run 2.0 gallons (a 17% Mixture)

I started after the MarioKart Tune and love it...NM Power Module was "Good"...the MarioKart RPM Tune is "Great" IMO

First AutoX coming up Feb 1st...we will see

 

Run the same mix per Mariokart, the car seems very happy with it. Been doing it for over a year and a half.

 

I'm very curious as to real world differences you notice with E85, and octane boost, if you don't mind?

 

PRICE...I bottle of Octane Boost is $7 and up and states it might raise Octane by 3 points

E85 or Ethanol at 10 % raises Octane in Pump Gas a few points

Bump it up to ~17% and 93 Octane is at 95 Octane or better

My Torque App shows a lower operating temperature but that could be because of the MarioKart RPM Tune

The best thing is so far??? Under Full Boost at 6500rpm the AFR (Air to Fuel Ratio) runs a steady 11.4-11.6 so it is not running lean and pulling better at high rpms...during normal cruising the AFR is at 14.2-14.7 or so

 

Perfect, thanks!

 

And I am leaning on the conservative side...it is probably even better boost but better safe than sorry...

Say 2 Gallons at 2.25 per gallon so 4.50 PLUS you get fuel mileage out of those 2 gallons compared to NO Measureable FUEL MILEAGE out of a 12oz Octane Boost

 

And you’re filling up with e85 from a standard e85 station? Nothing fancy?

 

Yep...from a Shell Station in New Braunfels, Texas. It has one Pump (each side of the pump) and then I top off the other with 93 Octane.
MarioKart says U can use 3 gallons for each fill-up which is about 27% E85