M3sparky
Full Access Member
i had a flex fuel on my 13 gmc denali and i used both 91 or e85 since it was compatible to use both, i didnt have it tuned for it but i def felt the power difference, its not anywhere close to the power difference you get on turbo engines but it def was felt. for the gtr, i had changed my injectors, fuel pumps , and later installed a flex fuel kit so i can use both fuels or mix them anytime i want without having to change my tune, you just feel a huge power difference with e85 from 91. i also heard its corrosive or leaves some build up inside the engine, but i was told to just run a tank of 91 every couple months or so and it woudl clean it away. so i did even less 91 than that maybe in 4 month or 5 id run 91 tank since i just hated the power loss , but i never had any issues, it just makes a massive amount of torque as well with the turbos more than the stock gtr internals could handle so my gtr after 5.5 years finally started to knock lol, so its been down a couple months now, prob going to just do a engine build and bigger turbos now. but aside from that it would be awesome to have a flex fuel kit for this truck.