Okay soo ever since i got my monte over a year ago it's been running on regular unleaded fuel, the 87 kind or whatever, bcuz my dad didnt want to pay the extra to put premium 93 in it. well i'm away from home and can get away with it and i know its better for my car anyway to have 93 in it.

so here's my question. it has about a half tank of 87 still left in it, would it screw the car up if i topped it off with 93 even though it is half full with 87? or should i wait until i'm on empty to do it? and if i had to go back to 87 for whatever reason would it screw the car up? i should know all this but idk why i'm getting so worried about it but i thought i would ask you guys about it and see what you think about all it. thanks for your future help

 

The cars computer will recognize the different octane and run on them accordingly because of the different fuel maps that have been coded internally. You really should have always been running 93 since you have the supercharged engine, but changing to it now will not hurt.

 

Hmm, always use 93.
The fuel flap tells me, "required" so i obey.

 

what exactly is 93 going to do better?

 

Premium gas has a higher octane, which means basically a higher resistance to spark knocking, which can happen when you punch the gas pedal. The result COULD be a chipped piston. It happens WAY to frequent, and is a major concern when you upgrade your engine, such as going to a smaller pulley on the S/C.
Run the highest octane gas you can, and just as important, stay away from the cheap gas and run Chevron, Shell, or the such.

 

yeah mine says that too on the flap but my dad refused to give me the extra money (since he wouldnt let me get a job i used his money all the time) for the upgrade. so its okay that i mixed the fuels then? and i usually get gas on the other side of town down by my school bcuz its so much cheaper but there arent any of the nicer stations like Shell, Chevron, and BP,,,there is only like TomThumb and Wal-Mart. Are those fuels gonna mess my car up if i keep using them? Up in Missouri I usually always used BP or Conoco gas but I don't have that option here. What should I do about that?

 

"Top tier" gas is something to look for, IMHO, but there are others as well. Here is 1 link, but google "top tier gasoline". Basically it's all about gasoline cleanliness and additives that keep your engine clean. Octane is important also, but dirty fuel injectors can cause your engine to run too lean, and that can be detrimental to your S/C engine as well. Here is 1 link. Check out the different pages in it, as well as other googled sites. Here is a relatively current list of "top tier" retailers. You might be surprised by who is NOT on this list:

http://www.toptiergas.com/retailers.html

TOP TIER Gasoline Retailers:

QuikTrip
Chevron
Texaco
MFA Oil Co.
Conoco
Phillips 66
76
Entec Stations
Shell
The Somerset Refinery, Inc.
Kwik Trip / Kwik Star
Aloha Petroleum
Tri-Par Oil Co.
Turkey Hill Minit Markets
Mileage Stations
Road Ranger
Chevron Canada
Shell Canada
Petro-Canada
Sunoco Canada

Also, some like Phillips 66, at least here in MI, only sell 92 octane gas. I'm tuned for 93 octane, so I don't run that brand.

 

i usually go to sunoco, usa, but i don't need the 93 octane, but is sunoco usa not good for regular 87 octane??

 

From how it works...

The octane rating of gasoline tells you how much the fuel can be compressed before it spontaneously ignites. When gas ignites by compression rather than because of the spark from the spark plug, it causes knocking in the engine. Knocking can damage an engine, so it is not something you want to have happening. Lower-octane gas (like "regular" 87-octane gasoline) can handle the least amount of compression before igniting.
The compression ratio of your engine determines the octane rating of the gas you must use in the car. One way to increase the horsepower of an engine of a given displacement is to increase its compression ratio. So a "high-performance engine" has a higher compression ratio and requires higher-octane fuel. The advantage of a high compression ratio is that it gives your engine a higher horsepower rating for a given engine weight -- that is what makes the engine "high performance." The disadvantage is that the gasoline for your engine costs more.

I run 93 in my LS1 Trans am, I run 87 in My Monte Carlo 3.8 N/A since it is not a high compression engine. Compression is the key with Octane. If you don't have a High Compression Engine it is a total waste of money, if you do have a High Compression Engine it is a must.

 

how about like a mobil station? and what would be best, just getting the most expensive gas or the middle or which one?

fully diesel? haha jk