87 octane

[JimmyJ_123]

When i got the truck. I filled the tank with 93 octane It idled like crap. Then i filled it with 87 it idled fine. The ECM must be set to run E85. Just wondered if others had similar experiences.

[Roader]

Unless you got 6.2 put 87 in it

[POS VETT]

That didn't make a lick of sense.

[Truckin 55]

The 2013 4.8 Vortec ran great on mid grade and E85 but 2014 EcoTec bogs down and hesitates. Mapco 87 seems to be the best brand and price in this area.

[07Softail]

That didn't make a lick of sense.

LMAO.... Gotta love gas and oil threads!

[JimmyJ_123]

LMAO.... Gotta love gas and oil threads!

Thats why I'm asking Einstein ? Didn't make sense to me. E85 is rated at 100-105 octane.

[newdude]

It doesn't make sense because you said:

 

Then i filled it with 87 it idled fine. The ECM must be set to run E85.

 

 

87 has nothing to do with E85. If you have ran nothing but 87 and then put a tank of 93 in, your fuel tables are mapped to 87 and would have to adapt to the higher octane, so the ECM will adjust tuning, etc. to try and run the 93.

[JimmyJ_123]

Thanks that is what i was looking for. Thanks for the knowledge.