running stock tune with 91 octane fuel help

[ti1andrezz]

I can usually get about 315-320 miles to a tank in my 2011 5.0 with 3.73s and an aftermarket tune running stock sized 27.25" tires. I use 93 octane daily. I live in Pittsburgh and right now with all of the movies being filmed here and bullshit construction, I get a lot of stop and go stuff, even on the highways.

oh ok mine is the 4.6 liter not sure if there is a big difference in the mileage. and mine is running on the stock tune setting, i drive on the highway mostly to get to where i need to get. i have not changed any of my driving habits and i am just at loss.

maybe try changing gas stations, change your oil, air filter etc.

i am almost due for my oil change ill do that later tomorrow after work ill run to the auto part store and get my oil and filter. i was thinking of that being something to do with it but i just wasn't sure but ill give it a try.

 

[MesaRec]

Disconnect the battery for at least 20 minutes, so the PCM resets. It will then relearn the fuel trims.

Do you have the "no tune" street kit?

 

[Seer]

i am almost due for my oil change ill do that later tomorrow after work ill run to the auto part store and get my oil and filter. i was thinking of that being something to do with it but i just wasn't sure but ill give it a try.

fuel injector cleaner, is the car idling ok? Possibly plugs? How many miles on the car?

 

[ti1andrezz]

idling sounds normal, and spark plugs i dont think i need those yet i just reached 33,000 miles on the car

Disconnect the battery for at least 20 minutes, so the PCM resets. It will then relearn the fuel trims.

Do you have the "no tune" street kit?

i actually have it sitting in the garage with the battery disconnected for the last ten min or so. and no, no tune at all its still on the stock ECU tune.

 

[MesaRec]

http://www.cnlperformance.com/notune.html
Do you have this?
Also, leave the battery disconnected for at least 20 minutes.

 

[ti1andrezz]

http://www.cnlperformance.com/notune.html
Do you have this?
Also, leave the battery disconnected for at least 20 minutes.

oh no it doesn't even have a Cold air intake yet that's why i asked the other gentlemen how he likes his new C&L because im thinking of getting the racer

 

[MesaRec]

I confused the statements. Must have been the Pulp Fiction reference.
FWIW, the Racer is a nice kit with a supporting tune. I went with the street though, and love it.

 

[Mike K]

Racer here and I love it!

The octane will have no effect on the mpg's but a little more pressure on the skinny pedal once in a while would have an effect.

 

[BruceH]

Do the usual stuff first. Change plugs or at least take them out and take a look, clean the maf, air filter.

FWIW with gasoline I get 25-26 highway, 18-19 combined. E85 is good for 19-20 highway and 14-15 combined. I'm running 4.56 gears, 28.5" tires, and a TR6060 6 speed.

EDIT: One more thing. The combination of living in Denver and using 91 octane on the stock tune could be contributing to fouling your plugs early. I'd run 87 with the stock tune, but thats me.