damn, i just paid $3.10 for E85 here in my town, suburb north of Houston, TX

 

Ha, we've got i think the 2nd most expensive gas in the country right now

 

I was using E85 for 5 tankfuls. then it went to $4.09/gal. i started using regular.

 

How much is UL87 in your area?

Conservatively speaking, lets say you lose 20% of your MPG when running E85 instead of UL87.

If you get 20 MPG running UL87 and 16 MPG running E85, from an MPG perspective you're better off running E85 until UL87 is at or above ~$5.10/gal (about 0.255 cents per mile).

 

Question for anyone who used to have a gen 1 (11-14) Coyote: did you observe the same results with that engine as you do on the current generation 5.0? Where premium eliminates pinging?

 

My '12 5.0 never pinged on 87. My '18 5.0 knocked no matter what I put in the tank. I ran everything in it. E85, 87, 89, 93, 89 and 91 ethanol free. I'd have put blue avgas in it if I still had the source I had 10 years ago but I don't think it would have helped.

 

If you're having problems pinging unless you're on premium, quite a few people here on the boards discovered their intake plenum was damaged and/or the gaskets between the plenum and the heads were no longer sealing, causing extra air and pinging.

 

how do you check that, because mine will ping unless im on 93.

 

I would, at this point, assume you've got a crack and/or gasket seal issue - some users were finding their truck/engine made a slight whistle-like sound when slow accelerating around the 2k RPM range, give or take. New plenum isn't that expensive, you can buy the seals separately too, i replaced mine as i once heard the noise when i was at higher altitude.

 

@[F2C]MaDMaXX did you find a crack in the manifold or was it a gasket issue on yours? I have an '18 and it makes a racket on everything but 93 and then still does it on occasion.