HOW TO ORDER 2020 5.3 THAT IS ABLE TO RUN ON E85

S12 · January 17, 2020

I live in Pa. I plan to order a 2020 GMC Sierra with 5.3 liter engine with the 10 speed transmission. Although I detest ethanol fuels, I realize that ethanol is not going away, and likely the percentage of ethanol will only increase in the future. How do I order this engine that is recommended to be able to use E85 fuel, having a yellow fuel cap and states that E85 fuels are recommended.. GM company "chats " are unable to answer this question, and will not research and respond. Dealers state they don't know either ??

redwngr · January 17, 2020

The short story is you can't get the E85 5.3 motor with the 10 speed.

The long story is:

RPO code FHS gets E85 capability on a 2020.

It can only be added to the L82 version of the 5.3.

(The new DFM 5.3 is the L84)

The L82 5.3 is only available on a Silverado WT or a base Sierra.

The 10 speed transmission is not available on the Silverado WT trim nor the Sierra 'Sierra' trim.

Can't get the 8 speed with the L82 either.

(but the 8 speed and the L84 version of the 5.3 can be ordered in the base trucks)

If you want E85 it's the 6 speed and the L82 version of the 5.2 AND the FHS rpo code.

Dealer should have been able to provide this info.....

OnTheReel · January 17, 2020

Short answer, you don’t. But there are people here going off the reservation and blending their own up to 50%, maybe even more, on the non-flex fuel motors. If you hate it, don’t worry about it.