Here in Central Florida we have 87, 89 and 93 octane gasoline. The way my reasoning works if I mix 87 and 93 octane gas 50/50 I have created 90 octane for my '05 5.4L.

What's the take on my thinking? Does gasoline readily mix with gasoline to create a true blend of the diffeent grades?

Mike, I have ordered my Xcal2 with a 87 and 93 performance tunes and a towing tune I am not quite sure of! If I paid 89 octane prices for 90 octane gasoline by mixing 87 and 93 50/50 would that be weoird or simply not recommended?

Thanks,

Ron Pierce

 

Mixing would be OK

 

Absolutely! In fact, at most stations, when you buy 89 octane gasoline, you get a mix of 70% 87 octane and 30% 93 octane. If it's not mixed at the station, it's mixed while loading the truck that delivers to the station.

Flagship

 

I had thought mixing was a no brainer. There was a little confusion when I was ordering on the phone with Crystal @ TP. I had indicated I'd like a 90 Octane (87/93 blend) performance tune but she indicated the tune should be for fuel grades available at the pump. I'll call tomorrow. I am probably still on a stack on the tuning desk.

 

Hi Ron,

Crystal advised you correctly - the long & short of it is that there just is no real practical benefit in mixing octane to get 90 octane tuning when you already have 87, 89 & 93 right there at the pump -

Here are the points that really get to the heart of it, and once you read this, I think you'll have a better appreciation for this.

For example, things like:

1.) There is no way you will consistently mix octane precisely down to 1 point accuracy like it's provided for you already at the pump, by just putting in some 87 and some 93 in equal amounts - unless that was all you *ever* ran and never changed to a different tune, And given the fact that we are tuning you for multiple octane levels, that isn't likely, so that simply will not happen with that kind of precision on a consistent basis. You would have to never change the octane level you are running, and thus never change tunes, *or* you would have to know down to the tenth of a gallon precisely how much fuel was in your tank at any given indicator level on the fuel gauge, and be able to mix to that level (actually, it's generally done even more precisely than that in what is delivered to you at the pump) - something that just won't happen in practical terms.

2.) Even if you could get *exactly* 90 octane like that on a consistent basis, you aren't going to get more than maybe 2 HP more at the wheels (if that) compared to what you will make on 89 octane tuning in your situation, in that vehicle.

Here's the clincher:

3.) We are already doing one of your tunes for 89 octane, and even if you did actually manage to put in exactly one point higher octane fuel on a consistent basis, you would *automatically* pick up any additional power that could be made with 1 point higher octane because of how we tune.

So given all of that, especially the fact that you will automatically get the benefit of another point of octane on your 89 octane tune, there just is no need or practical benefit to trying to mix down to 1 point octane precision yourself like that, so I would just take the fuel as it is dispensed at the pump.

While octane mixing is, generally speaking, relatively linear, that is really only useful & practical primarily when mixing to a larger octane differential than just 1 or 2 points. I.E., such as when adding 104-110 octane race gas to 93 octane pump premium to bring it up to 100 octane, for those customers of ours who are drag racers driving the same vehicle on the street and need a 100 octane race gas type of tune for the drag strip. In that scenario, they are mixing to a far greater octane differential, and they are doing it only from 1 point on the gas gauge - the point at which the low fuel light first comes on. They have filled the vehicle up numerous times at the same pump from that same point, and thus know very well how much 104-110 octane race fuel to add in to get the 100 octane they need - and the far more important point that they are mixing to a far greater octane differential, 7 points instead of just 1.

I hope that gives you a better understanding!

 

Thank you for taking the time to spell that out, Mike. I will shutup now and wait for the truck.

 

Hi rooster,

You are more than welcome, of course!

And by the way - please don't "shut up," and I hope I didn't give you the impression that you should! I must confess that 'm not a particularly effective writer, which is why I sometimes worry about trying to discuss some things via the written word - due to my lack of skills as a writer, sometimes the way I phrase things may come off in a different manner (or tone) than what I really intended - so I truly hope I didn't give you that impression!

This is the place where people come to talk about things like that, & so many other aspects of power production, fuel quality, etc. A lot of other people who never post here come here daily to read every post, to learn all they can - so just speaking personally, I think this discussion regarding mixing octane down to such a fine point certainly is/was a relevant topic to discuss, and some good info to have just in general.

And all of that being said, if this is something you want to do - meaning you want to go ahead and play around with mixing your octane like that - by all means, have at it! Like I said before, if you do add another point of octane in the tank - for example, on your 89 octane tune you run 90 - or on one of your 93 octane tunes, you actually run 94 octane - you will pick up any additional power that affords "automatically," due to the way we tune. One note on that is that you don't want to add a *significant* amount of octane above & beyond what each tune is set up for - I.E., you wouldn't want to run 98 or 100 octane on your 93 octane tunes, that is too much and would actually reduce power, as that much additional octane needs to be tuned for. But adding 1-2 pints of octane above what each tune calls for will result in you picking up a bit more power, because of how we tune.

I hope that gives you a bit more insight on this, & I really just hope I was able to offer my thoughts on that in a manner that was helpful - thanks for your posts, & if you would like to go over any of this in more detail, please feel free to give us a call, OK?

Good luck & have fun,