93 Octane - No Tune
08-07-2009, 12:21 PM
#1
2nd Gear Member
Thread Starter
Join Date: Jul 2009
Location: Maryland
Posts: 380
93 Octane - No Tune
So, ever since I got my 2008 GT about a month ago, I've been running 93 octane. Just now starting to wonder if I shouldn't be doing that.
In the owner's manual it recommends 87, yet, it talks about light knocking being ok, and to avoid that I've just been running the 93. But I'm thinking, maybe I could be loing power due to the gas being hard to ignite.
Should I switch to 87? Perhaps 91? All is BP gas, if that matters. I drive my car pretty hard, so I'm not sure.
In the owner's manual it recommends 87, yet, it talks about light knocking being ok, and to avoid that I've just been running the 93. But I'm thinking, maybe I could be loing power due to the gas being hard to ignite.
Should I switch to 87? Perhaps 91? All is BP gas, if that matters. I drive my car pretty hard, so I'm not sure.
08-07-2009, 01:36 PM
#2
4th Gear Member
Join Date: Jul 2007
Location: CA
Posts: 1,914
So, ever since I got my 2008 GT about a month ago, I've been running 93 octane. Just now starting to wonder if I shouldn't be doing that.
In the owner's manual it recommends 87, yet, it talks about light knocking being ok, and to avoid that I've just been running the 93. But I'm thinking, maybe I could be loing power due to the gas being hard to ignite.
Should I switch to 87? Perhaps 91? All is BP gas, if that matters. I drive my car pretty hard, so I'm not sure.
In the owner's manual it recommends 87, yet, it talks about light knocking being ok, and to avoid that I've just been running the 93. But I'm thinking, maybe I could be loing power due to the gas being hard to ignite.
Should I switch to 87? Perhaps 91? All is BP gas, if that matters. I drive my car pretty hard, so I'm not sure.
Run it on 87 no need to spend the extra money on the 93 without a tune and some mods.
08-07-2009, 01:52 PM
#3
3rd Gear Member
Join Date: Oct 2006
Location: Spring, TX
Posts: 816
So, ever since I got my 2008 GT about a month ago, I've been running 93 octane. Just now starting to wonder if I shouldn't be doing that.
In the owner's manual it recommends 87, yet, it talks about light knocking being ok, and to avoid that I've just been running the 93. But I'm thinking, maybe I could be loing power due to the gas being hard to ignite.
Should I switch to 87? Perhaps 91? All is BP gas, if that matters. I drive my car pretty hard, so I'm not sure.
In the owner's manual it recommends 87, yet, it talks about light knocking being ok, and to avoid that I've just been running the 93. But I'm thinking, maybe I could be loing power due to the gas being hard to ignite.
Should I switch to 87? Perhaps 91? All is BP gas, if that matters. I drive my car pretty hard, so I'm not sure.
Worry about it if you get a blower or a intake/tune.
08-07-2009, 02:54 PM
#7
3rd Gear Member
Join Date: Oct 2006
Location: Spring, TX
Posts: 816
08-07-2009, 10:06 PM
#8
6th Gear Member
Join Date: Feb 2007
Location: North Carolina
Posts: 11,302
No gains from 93 without a tune, Vista. Run the 87 for now and save that 20 cents per gallon. You can run the 93, it won't hurt anything, just won't gain anything either. Get that thing tuned, it'll surprise you just how detuned it is stock.
08-08-2009, 10:24 AM
#10
4th Gear Member
Join Date: Mar 2006
Location:
Posts: 1,470
+1 on installing a 93 octane tune(and a CAI). Huge difference when compared to the stock setup, and it's the best bang-for-the-buck performance mod for these cars IMHO.
But if you plan to stick with the stock setup, then suggest using 87 octane if the engine is not pinging, since incomplete combustion may occur when using 93 octane with the stock tune, which can cause carbon build up in the combustion chambers and premature catalytic converter failure(as mentioned by PSUSkier).
If the engine pings with 87 octane, then recommend increasing the octane in steps(89 -> 91 -> 93) until the pinging stops.
But if you plan to stick with the stock setup, then suggest using 87 octane if the engine is not pinging, since incomplete combustion may occur when using 93 octane with the stock tune, which can cause carbon build up in the combustion chambers and premature catalytic converter failure(as mentioned by PSUSkier).
If the engine pings with 87 octane, then recommend increasing the octane in steps(89 -> 91 -> 93) until the pinging stops.