The Mustang Forum for Track & Racing Enthusiasts

Taking your Mustang to an open track/HPDE event for the first time? Do you race competitively? This forum is for you! Log in to remove most ads.

  • Welcome to the Ford Mustang forum built for owners of the Mustang GT350, BOSS 302, GT500, and all other S550, S197, SN95, Fox Body and older Mustangs set up for open track days, road racing, and/or autocross. Join our forum, interact with others, share your build, and help us strengthen this community!

Octane

BossMan

Hello everyone,

I currently own a 2008 Mustang Bullitt and I have begun my research on the Boss. The return of the Boss has made me rethink if now is the time to upgrade.

One of the things I liked that ford incorporated was the Dual knock strategy enabling the vehicle to run on either regular unleaded or premium (for improved performance). Was this carried over to the Boss?
 
1,255
0
GA
BossMan said:
Hello everyone,

I currently own a 2008 Mustang Bullitt and I have begun my research on the Boss. The return of the Boss has made me rethink if now is the time to upgrade.

One of the things I liked that ford incorporated was the Dual knock strategy enabling the vehicle to run on either regular unleaded or premium (for improved performance). Was this carried over to the Boss?

I find the dual knock thing to be a waste on the Bullitt. I get better gas mileage using 93 octane and use less fuel overall than 87.

I know Track Key requires at least 91 octane but I think you can run 87 on the street tune.
 

BossMan

Thanks for the reply. I actually went by a dealer today to ask questions and he said that it would run on regular was well. I assume you own or owned a Bullitt regarding the gas mileage. I ran 93 for about a month without really noticing that much difference in HP and the gas mileage was no different. I do understand that the 5.0's are higher compressed engines and the engine responds much better.

I am weighing my options to buy but one dealer wants an ADM. The CO Boss is a sweet color!
 
1,255
0
GA
BossMan said:
Thanks for the reply. I actually went by a dealer today to ask questions and he said that it would run on regular was well. I assume you own or owned a Bullitt regarding the gas mileage. I ran 93 for about a month without really noticing that much difference in HP and the gas mileage was no different. I do understand that the 5.0's are higher compressed engines and the engine responds much better.

I am weighing my options to buy but one dealer wants an ADM. The CO Boss is a sweet color!

I still own 2008 # 572. I get noticeably worse gas mileage and performance on 87 octane, so I stick with 93. Even though it is my DD I don't drive far enough for the price difference to be a concern. I would love a Boss but at the moment I can't swing it until I pay down some debt and at least get it at MSRP (which will happen if I am patient). The CO is cool; Yellow Blaze or Kona Blue are my preferred colors for MY2012 and Grabber Green for MY2013.

Good luck on your search. :)
 

BossMan

Have you had any issues with your tranny? I had the 3rd gear syncros replaced a few months ago. Seems to be better but I have noticed a notchy feel in 4th from time to time. All in all the car is a very fun car to drive with looks to boot.

I never thought I would ever want to part with her but the Boss has changed that. They wanted 3K over sticker and were giving me 22K with trade. The dealer I bought my Bullitt (#862) from would do Msrp but I will have to wait until Nov. Good luck!
 
1,255
0
GA
BossMan said:
Have you had any issues with your tranny? I had the 3rd gear syncros replaced a few months ago. Seems to be better but I have noticed a notchy feel in 4th from time to time. All in all the car is a very fun car to drive with looks to boot.

I never thought I would ever want to part with her but the Boss has changed that. They wanted 3K over sticker and were giving me 22K with trade. The dealer I bought my Bullitt (#862) from would do Msrp but I will have to wait until Nov. Good luck!

I had the 3rd gear grind when cold and had the TSB done. That was about 16 months ago and it has been fine since, although it has loosened up a little again since then. Sometimes the synchros are a little slow to catch up between shift and I feel a slight notchiness at times. I am still pleased overall with the car so if I don't do anything I will still be happy. I was offered 18K for a trade and the car has just over 30K, which seems a little low compared to some others. I know the car is going to need upgrades and big maintenance soon so I feel like I have a short window to do something. Buying a 2011 GT and getting power pack and adjustable suspension pack installed before delivery makes a lot of financial sense given the 0% financing and rebates.
 
548
0
I'm not sure the Boss would/should run on 87 octane. In any case, the Boss literature from Day one has said premium unleaded is required. If you actually add up the difference in cost over a 12 month period, I don't think you even spend over $150 a year to fill regularly with premium over regular. If the efficiency and miles per gallon are actually as good or better burning premium, then that cost would actually be lower. In any case, personally I think running premium unleaded in a Boss is a given.
 
jimprw said:
I'm not sure the Boss would/should run on 87 octane. In any case, the Boss literature from Day one has said premium unleaded is required. If you actually add up the difference in cost over a 12 month period, I don't think you even spend over $150 a year to fill regularly with premium over regular. If the efficiency and miles per gallon are actually as good or better burning premium, then that cost would actually be lower. In any case, personally I think running premium unleaded in a Boss is a given.
I agree. I run 93 almost exclusively, but will settle for 92 when that's all I can get. I prefer a margin of safety, particularly if you're running it hard. I definitely wouldn't run less than 91.
 
2012Boss said:
I am running 90 with pure gas. I would like higher but that is all I can get here, I feel it is better then E10 even at 90.
Probably so. Can't find pure high octane gas around here in the heart of corn country. 87 is the only readily available non-oxygenated gas. There is one station north of town with non-oxygenated 93 but it's too far unless I'm filling up gas cans for the track.
 
2012Boss said:
www.pure-gas.org
http://pure-gas.org/index.jsp?stateprov=SD
Thanks Scott. Wow, one station in town. I didn't realize that one had 93 non-oxygenated gas. I'll be going there this week to check it out. Funny thing is that operator owns dozens of stations in town, but that's the only one listed as non-oxygenated.
 
Big Vito said:
What would be better, 93 with ethanol or 91 pure gas?
Perry, I'm certainly no expert, but here's the little I know from talking to some tuners. Higher octane fuels burn at a higher temp so reduce chances of detonation which can obviously damage your engine. Ethanol is actually a much higher octane fuel than pure gas. That's why you'll see pure gas at 87 octane and regular E10 at 89 for a little less money (subsidy). There are several cars around here tuned to run E85 and it has an octane rating much higher than race gas.

However, if I understand it correctly, ethanol also leans out the fuel mixture. So you have to tune for a richer a/f ratio to avoid a potential lean condition, which could damage your engine. I would assume this is a reason your fuel economy is lower running ethanol. They sell E85 around here for about 15-20% less than regular gas, but I'm told the fuel economy is up to 30% less.

My guess is that Ford's factory and TracKey tunes are able to safely compensate for either oxygenated or non-oxygenated tunes as long as you're providing a high enough octane to avoid detonation. They may also be able to compensate for that assuming we have factory knock sensors. I know we have factory widebands because I can pick up a/f on my Aeroforce gauge.

Anyway, those with more detailed knowledge please expand.
 
1,429
344
Gary- Is the Boss OBDII or have they gone to OBDII or something? I have an AutoEnginuity scan tool for my 99 PowerStroke 7.3 that would be nice to hook up to the Boss...

Andy
 
Thanks Gary,

Lots of good to know info there. I have two stations that I call near me the closer one is 91 pure gas.
cloud9 said:
Big Vito said:
What would be better, 93 with ethanol or 91 pure gas?
Perry, I'm certainly no expert, but here's the little I know from talking to some tuners. Higher octane fuels burn at a higher temp so reduce chances of detonation which can obviously damage your engine. Ethanol is actually a much higher octane fuel than pure gas. That's why you'll see pure gas at 87 octane and regular E10 at 89 for a little less money (subsidy). There are several cars around here tuned to run E85 and it has an octane rating much higher than race gas.

However, if I understand it correctly, ethanol also leans out the fuel mixture. So you have to tune for a higher a/f ratio to avoid a potential lean condition, which could damage your engine. I would assume this is a reason your fuel economy is lower running ethanol. They sell E85 around here for about 15-20% less than regular gas, but I'm told the fuel economy is up to 30% less.

My guess is that Ford's factory and TracKey tunes are able to safely compensate for either oxygenated or non-oxygenated tunes as long as you're providing a high enough octane to avoid detonation. They may also be able to compensate for that assuming we have factory knock sensors. I know we have factory widebands because I can pick up a/f on my Aeroforce gauge.

Anyway, those with more detailed knowledge please expand.
 
Fat Boss said:
Gary- Is the Boss OBDII or have they gone to OBDII or something? I have an AutoEnginuity scan tool for my 99 PowerStroke 7.3 that would be nice to hook up to the Boss...

Andy
Hey Andy - Yes the Boss is OBDII and the port is under the left hand side of the dash on the driver's side.
 
To me octane rating is not as important as using E10 or any combo of it. Someone can correct me if I am wrong but basically octane rating is the temp at which a fuel will burn, the higher the octane the more stable the burning temp. That is why it is only recommending in higher compression engines. I don't use higher octane in the F150 and it was not designed for it. It would be a waste of money and can also be bad to run when the car was not designed for it.

Today's engines are very different with knock sensors and more. The big problem years ago was carbon build up on a piston top. That would heat up and if a lower burning lower octane gas was used the heated carbon would set it off causing pre-detonation. This would not only cause a power loss by having it fire before the piston was at the top of the power stroke but could harm the engine for obvious reason. This is not something I would worry about with the Boss, the octane would be only of concern because of compression ratio and how a tune will effect timing.

The thing about adding ethanol to gas today is it is used to raise the octane level of crappy gas. If it does not mix well (which it does not) and burns at a uneven rate you can have all kinds of problems with what is left in a higher compression engine.

This is very basic info, I suggest you read up on the subject, there are many sites that talk about it.
 

TMO Supporting Vendors

Latest posts

Buy TMO Apparel

Buy TMO Apparel
Top