A question regarding 89 octane on a 2007 300C

[metalmancpa]

First post here, so Hi everybody.

Question - I live in MA and run 89 Octane fuel. I read this in the forum:

17) Running 89 or 100 Octane Fuel

Since the introduction of this tool, many have asked if they can run 89 octane fuel with a Predator tune. The answer is Yes and No! If you are going to install a Canned Tune shipped with the Predator, you Must run at least 91 octane and NO you cannot run 89 octane fuel. Diablosport has authorized using Modify Tune on the Perf 91 or Perf 91 CAI tune, by retarding timing 2 degrees in all six WOT Spark settings to run 89 octane fuels, so in this case, YES you can once timing is retarded 2 degrees as listed. Make sure you log some WOT passes and play them back to insure no LT Retard appeared. Similarly, if you are at the race track and can purchase 100 Octane Low Lead, you can Advance the timing of the 91 octane tune by 4 degrees, maybe 5 with data logging to check for knock.

I haven't received my predator yet (just ordered), but am wondering if this timing setting is easy? Once I load the canned 91 CAI tune, before even turning on the engine should I make this adjustment?

Thanks

[mikel]

It is simple, but I cant understand for any reason why you would want to run low octane fuel in a high performance engine, especially when you went out and bought a Predator, presumably to improve its performance?

[Cruisin1966]

Yes, it's quite easy.

You only need to adjust timing if you plan on running at WOT (wide open throttle), because that's the only place you can adjust the timing. If you're driving the car conservatively, you're fine, but if you're already loading a canned tune, select the Modify Tune option and go to the WOT Timing option and retard the timing 2º in each of the listed areas.

[metalmancpa]

It is simple, but I cant understand for any reason why you would want to run low octane fuel in a high performance engine, especially when you went out and bought a Predator, presumably to improve its performance?

Hi Mike,

Being a newbie to owning a vehicle with a performance engine, the reason I am running 89 octane is that it is suggested in the owners manual. That, coupled with gas prices of the higher octane, and also where I have heard running higher octane in colder environments can be cause for harder starts, is why I am still on 89 octane.

So with that being said, as I venture into higher performance (Diablo Predator and Aria Carbon Fiber CAI both on order), I have been researching. Since I am moving to the Predator, and my Octane choices in MA are 89 and 93, what direction should I head with the knowledge I have to date - modify to run 89 Octane or would I have to modify a canned tune if I were to switch to 91 octane? Is the cold weather comment true about higher octanes?

Thanks

[metalmancpa]

Yes, it's quite easy.

You only need to adjust timing if you plan on running at WOT (wide open throttle), because that's the only place you can adjust the timing. If you're driving the car conservatively, you're fine, but if you're already loading a canned tune, select the Modify Tune option and go to the WOT Timing option and retard the timing 2º in each of the listed areas.

I generally run 75-80MPH on the highway. I don't race, but have fun quickly getting up to speed. So what would be good for me?

[Cruisin1966]

Fill up with 93 oct fuel before everything arrives. Load the Perf 91 CAI canned tune. Go driving. That's truly what's best. Now, if you're going to decide to run the 89 oct fuel, retard the timing when you load the tune.

[metalmancpa]

I also just saw this on the 7135 product information page:

NOTE: The use of respective grade fuel should be used with tune choice.
91 octane tune will run on 87,89 and 91 octane. The 93 octane (Performance) tune will run on 91 and 93 octane.

The way I read this is the 91 tune will work on the 89 octane fuel. If I decide to use 93 octane if there are true benefits for using higher octane fuel in my car, then I would run a few tanks before uploading from the predator and would use the 93 octane tune.

Do I sound like I even have a smidge of a clue what I am talking about?

[Quick]

If I decide to use 93 octane if there are true benefits for using higher octane fuel in my car,

Your car can be made to go faster.