You must have one of the special motors my 2018 5.0 is able to run E85. No one here in Abilene sells it that I know of and I wouldn't buy any if they did.

 

You're absolutely right. That's what I get for using a calculator made in China. The real number is 3.3% mileage reduction. But that depends on what numbers you use. The EPA and Department of Energy list a range of heat values for regular gasoline and for ethanol so there is a range of answers. Not that anyone could actually see a 3 or 4 percent reduction in mileage in one vehicle but spread across a couple of tens of millions of vehicles it does add up.
On top of that E85 isn't always E85. According to the DOE, refiners vary the percentage of ethanol in E85 from 56% to 85% depending on the season and the location in the country where the fuel will be sold. The colder the local temperatures the less ethanol in E85. It can just never exceed 85%.

Here's something else to obsess about. Our esteemed elected and appointed officials want to raise the percentage of ethanol in regular gasoline to 15%. A lot of vehicle manufacturers state specifically in their owner's manuals that using fuel with more than 10% ethanol will void the engine warranty. I can see that recreating the situation of leaded / unleaded fuel. You'll have to find a station that still sells the "old" E10. This is what happens when elected officials know NOTHING about the end result of the laws they pass. But hey, the farmers have to do something with all that excess corn.

 

Sorry for the delay. Been busy with other things and haven't been around the computer much. Truck is fine now. We had a day where temperatures rose up to 53 and it started fine on that day. He ran the tank near empty and switched back to unleaded.

 

 

That's interesting. What MPG does it get with E15 and otherwise?

 

That actually makes some sense. E15 is higher in octane than regular and with modern computer controlled engines the computer can set more ignition advance under heavy towing loads than it can with non-ethanol fuels. But what about when unloaded?

 

Ethanol is both an oxygenate (helps emissions), and an octane enhancer. So even though it is lower energy density than gasoline, in small quantities, it can allow better ignition advance and higher compression. Both of those can enhance power. So it's a matter of degrees (no pun intended there).

 

Here's something interesting I observed last week. I've got a Bluetooth dongle in my 2018 5.0L F150 OBD2 port, so my phone can run Torque Pro diagnostics. I have one of my gauges in Torque Pro set to monitor ethanol % , as the 5.0L is a FFV and has an ethanol sensor. Typically, my gauge reads around 9.8% ethanol after a fill-up with E-10. Pulled into a local station and topped off (15 gal) with E-10. Ethanol gauge started immediately ratcheting up! Once it finished mixing with the other 21 gallons, it read 22.4% ethanol!

Needless to say, my gas mileage suffered for that tank. Best I can figure, their E-10 tank is dispensing E-40, or thereabouts. I plan to go back in another week or so and check it again.
Here's a shot before the tank finished mixing:

 

2020 F150 5.0 Coyote. Purchased at 8k miles. No knocks or pings, just the normal high pressure fuel pump noise everyone complains about. I manage a lube center so im on top of my maintenance. I use Liquid Moly 5w20 and change it every 3500 miles. I don't care what anyone says about oil and its longevity. All oil no matter the brand starts breaking down around 2500 miles and loses complete viscosity after 5-6000 miles. Anyways, I have 13,800 on it now and have been running E85 every 3 tanks and 93 on the 4th. This past week I have noticed at start up the rpms are surging up and down and makes a terrible (alarming) noise on the passenger side coming from the high pressure pump. It levels out and quiets down after 8-10 min of idle but I'm concerned that the E85 has no lubrication properties. I love the performance from the E85 and I bought a truck so definitely not concerned about fuel mileage as I have 33x12.5/22 wheels. Just wondering if anyone else has came across this issue? It is going to the shop Monday, so I will update this then.