going from 87-91 octane once tune is installed???

[J.Cagle]

Whats the best way to do this? My tune should be this week. I have been keeping my take real low so I can get as much 91 in it when I fill up after the instal of the tune, but with the little bit of 87 left wont the fuel be slightly lower octane and affect the way it runs?

 

[kooldawg6]

Go ahead and fill up with 91. Run it down and fill back up with 91 before the tune and you should be fine. Running 91 in your car now won't hurt anything. It will just waste a marginal amount as it can't combust it all.

 

[Informant736]

if your expecting to get the tuner soon and dont put that many miles on the car, i would only fill up like 1/3 - 1/2 tank or so with the 91 and run that down then fill up again on 91 before loading the tune. This way your not waiting longer to load the tune because of a full tank of an 87/91 mix of fuel.

 

[J.Cagle]

I ran my car til the thing said I had 20 miles left til empty. Which should be about 1 gallon left. I just put 20 bucks of 91octane in a second ago( about 9 gallons). By the time i get the tune and get my intake and stuff put on so I can install the tune I will need to get gas again Im sure and will fill up with 91 then. That should be good don't ya think?

 

[kooldawg6]

That should be fine.

 

[TPony]

any of the suggestions above should work fine

 

[J.Cagle]

I just filled up again with 91. (been doing alot of driving this weekend) I think all the 87 should be flushed out. Its wierd, running 91 has increased my average fuel milage from 21.5 to 23.8. I really thought it would hurt since it wasnt tuned to run on 91. Plus it has turned my exhaust tips black and look nasty.

 

[kooldawg6]

I don't know what the coincidence would be that would increase your mileage Everything should nearly be the same excpet for the fact the engine can't combust all the gas at a higher octane rating. But the black nasty soot is what's not being completely burned up before it leaves the muffler. That also happens when you eliminate the cats a lot of the time regardless of octane/tune.

 

[J.Cagle]

Thats what I have heard about running no cats. Looks like Im going to be doing alot of exhaust tip polishing when I decide if an O/R H-pipe adds much power and get one

 

[kooldawg6]

Thats what I have heard about running no cats. Looks like Im going to be doing alot of exhaust tip polishing when I decide if an O/R H-pipe adds much power and get one

No need to do a lot of polishing! Use a name brand metal cleaner/polish (I've been using Eagle One Nevr-Dull for several years now with no problems) first thing and I use a mesh pad when washing the tips and that is enough to get the residue off on a weekly basis. I only breakdown and repolish them maybe twice a year.

 

[J.Cagle]

never dull is some pretty good stuff. Also BlueMagic Metal polish is pretty good as well. It works great on aluminum wheels with a mothers powerball.

 

[Ken04]

Whats the best way to do this? My tune should be this week. I have been keeping my take real low so I can get as much 91 in it when I fill up after the instal of the tune, but with the little bit of 87 left wont the fuel be slightly lower octane and affect the way it runs?

worse comes to worse you could always throw in a can of octane booster.