Thank goodness for our Yukon being Flex Fuel

[swathdiver]

This subject has bothered me so I did a little more googling and came across this:

GM TSB : PIP5227 (edited for brevity)
Please note: There was a change during the production of 2015 Full-Size SUVs, and with the beginning production of 2015 Full-Size Light-Duty Pickups, shifting from a standard E85 capability on all of these vehicles equipped with the L83, 5.3L V8, to an optional E85 capability, requiring selection of E85 capability through vehicles equipped with RPO code FHS.

Note: Vehicles equipped with RPO FHO, E10 gasoline are certified for this fuel type and cannot be modified to allow use of E85 flex-fuel.

In the past, GM would give a new name to an engine, like the LH6 becoming the LC9 because of the Flex Fuel but I guess they were tired of adding engine numbers.

So, you fellas with L83s and black gas caps or filling ports, you probably have RPO L83 and FHO.

 

[GranPrix]

The wifey freaked out and wanted to go north. We gassed up Tuesday morning and shot up SR27 to Crystal River just north of Tampa with just over half a tank left. Stayed there about two days, topped off again and went across to Jacksonville. We got back last night with very little traffic.

For those using E85 isn't the mileage worst? I know I had horrible mileage with my Crown Vic when I used E85

 

[79jasper]

Ours get slightly worse mileage with E85. But the cost differences makes up for it.
What's funny is for our '10, they claim higher hp on E85.
335 / 454 @ 4000* (gas)
348 / 472 @ 4400* (E85)
But could just be a marketing ploy. The difference could be that 400 rpm.

Sent from my SM-G892A using Tapatalk

 

[swathdiver]

13 horsepower on a 6,000lb truck is going to be tough to feel! Mine is rated to pick up 6 horsepower on E85. But I wonder what kind of E85? In learning about E-85, the 85 was originally identifying the amount of Ethanol in the mix. But nowadays, E85 can contain anywhere from 51-83% Ethanol. That's got to affect our mileage. In addition, the gasoline used can be anything else as well. So it's not consistent, at least numbers wise.

I've only run one tank of E85 from a Racetrac during the hurricane while out of town. The stations up my way are just as expensive save for the Shell on the Turnpike which is $1.99 right now. Having said that, I do not know how much those factors (Ethanol Content and Quality of Gas) affect the overall performance from station to station, brand to brand or season to season.

Curiously, this tank of E85 is getting BETTER or Comparable mileage (13.4 city/15.4 Hwy) than the gas from my regular Sunoco station (12/16). Think it's time to switch back to Exxon/Mobil for a couple of tanks then over to Shell for some E85 testing.