The dealer that delivered the car says the 87 octane fuel is ok for the car. I could not find anything in the Boss 302 Supplement Manual about what the correct rating of fuel to use.

I am running 93 octane fuel now but was just wondering what are we supposed to be running?

 

higher the better, the ecu should pull timing for lower grade, but a Boss, i would put nothing other than 93..

 

Tech specs and Owners manual say Premium fuel is "recommended".

 

I run 91 (High Altitude, all that is available) as the car sees (and will see more) track duty. According to the owner's manual, you can run anything and the EEC adjusts for it (knock sensors most likely used to pull timing).

For a long highway cruise, I'd have no problem running regular... Did it in my M3 for years when driving to distant events. Filled up with Super before going on the track and no issues (10 years).

 

The best in Alaska is 90, so I am stuck with that. I thought about 87 for trips but have not tried it yet. I know that the EEC will adjust, but that thought that you may be at the edge of knock for the sensers to pick it up would bother me.

 

You can run 87 but it pulls timing and reduces HP. Personally I run the highest octane available at the pump and that's about .20 cents more a gallon than 87 in most areas. You're talking 3 dollars at the most per fill up and to me that's nothing considering the car cost over 40 grand.

 

I've put 87 in plenty of times. The car should be at the edge of knock at all WOT conditions anyway.

 

I ran out of gas at the track (HPR) last week. So, only choice was the track premium (98, 100+) octane. Put in half tank of 98 and car ran no better than 91 that I normally use.

Actually, now that I think about it, my overheating and limp mode issues started after I put the 98 Octane in the tank...

 

[QUOTE=rmaginnis;6108532]I ran out of gas at the track (HPR) last week. So, only choice was the track premium (98, 100+) octane. Put in half tank of 98 and car ran no better than 91 that I normally use.

Yep, higher octane will usually only show its benefit if the ECU is tuned to know you are using it and adjusts the timing accordingly.

 

93 only for me....

 

-->91<--

 

91 till red key is programmed.

 

David - This has already been covered. Depends on which key you use and 87 is fine with black key. See
https://themustangsource.com/f813/so...495813/index3/