Toyota GR86, 86, FR-S and Subaru BRZ Forum & Owners Community - FT86CLUB - View Single Post

CincyJohn · 03-15-2021, 11:43 AM

I've read a lot of the archive threads on this topic, so I think I know the answer already, but I am just checking.

Just recently switched to JDL UEL catless headers, switched the OFT to off-the-shelf 2+ e85 (MY2020 BRZ, US manual. 10k miles). I am on my second tank of e85 and I have no idea what the actual ethanol percentage of the gas is (the pump says guaranteed between 51% and 83%). I have looked at my STFT/LTFTs off and on and they are consistently between +/- 3%. I haven't heard anything I would describe as knock (or anything I think sounds odd at all).

I think this is all fine and there is nothing I need to worry about, but could someone confirm? Also, do I need to keep checking my LTFTs/STFTs every time I put in a new tank of fuel? Or maybe just every time I put in a new tank from a new station? I am assuming that most stations around me (at least from the same company) are providing the exact same e85 mix.

Second, it is weird but my computer estimated gas MPG has not changed much - if anything it has gone down from 28MPG to 27MPG. Does this make sense?

03-15-2021, 11:43 AM	#1
CincyJohn Senior Member Join Date: Aug 2020 Drives: 2022 MT Neptune GR86 Prem. Location: Cincinnati, OHIO Posts: 492 Thanks: 143 Thanked 315 Times in 199 Posts Mentioned: 0 Post(s) Tagged: 0 Thread(s)	LTFT/STFT on e85 ... I've read a lot of the archive threads on this topic, so I think I know the answer already, but I am just checking. Just recently switched to JDL UEL catless headers, switched the OFT to off-the-shelf 2+ e85 (MY2020 BRZ, US manual. 10k miles). I am on my second tank of e85 and I have no idea what the actual ethanol percentage of the gas is (the pump says guaranteed between 51% and 83%). I have looked at my STFT/LTFTs off and on and they are consistently between +/- 3%. I haven't heard anything I would describe as knock (or anything I think sounds odd at all). I think this is all fine and there is nothing I need to worry about, but could someone confirm? Also, do I need to keep checking my LTFTs/STFTs every time I put in a new tank of fuel? Or maybe just every time I put in a new tank from a new station? I am assuming that most stations around me (at least from the same company) are providing the exact same e85 mix. Second, it is weird but my computer estimated gas MPG has not changed much - if anything it has gone down from 28MPG to 27MPG. Does this make sense? Last edited by CincyJohn; 03-15-2021 at 02:54 PM.