Is it necessary?

 

What's the squeeze under the heads? 10.5? 11.5?

 

Yeah. The car will run on low octane -- the ECM will back off on the timing -- but it won't like it. Mine has never seen a tank of anything but 91 or 93 octane, even when stock.

I guess my attitude has always been if you really have to worry about the slight difference in price between premium and regular, then the 'vette probably isn't your car anyway.

If the car has been tuned to optimize performance (whether stock or not) it becomes even more important to stick to premium, by the way. You can often pick up some power and fuel economy with a good tune, but it removes the "margin" the factory put in.

 

How 'bout if you go to the airport and get some of that 103 octane, for the 4 cylinder Lycomings??? Will the new engines advance the timing to 30' BTDC?

 

Premium gas is required for maximum power & engine life when you are driving hard. If you have a stock LT1 and are cruising the expressway it will not know the difference between regualr & premium because you are not on it hard enough to need the extra octane.
On the other hand, if the engine is at all modified, it needs higher octane. If it is an LT4 (was that available in 2004?) it has greater need for high octane. If you have a heavy foot, it needs higher octane.
And no, it will NOT advance the timing beyond the factory setting if high octane racing fuel or aviation gas is used, it only retards if knock is sensed, it does not overadvance.

 

will it run on diseal fuel?

 

No, it will advance to the limit of its programmed range and stop there, depending on things it may produce a bit more power. A BP station near here has one pump that sells 103 octance racing gas for $3 per gallon over normal premium. When my car was near stock (headers and CAI was about all) I put in a tank and it felt just a tad peppier and it dynoed about8 RWHP more (i.e, about 2.1% more from an extra 10 cotane points). The shop then advanced the timing via re-programming the ECM and it jumped to 15 RWHP more (but we had to drop it back since I would be going back to normal fuel most of the time)
Now that the engine is so very modified and all ECM tolerances are opened up the car responds much more: puttingin 103 octance (or a couple of cans of octance booster) adds about 35-40+ RWHP (over 5%) over the power it produces on 93 octance fuel, as the computer responds.
And to answer a question folks often ask: theECM figures it out in milliseconds - this is not a slow adaptive change: fill a mostly empty tank of 93 octane with 103 octane , and the additional 35 RWHP is there from the moment you start the car again.
One way my son has learned to tell that I'm worried about a match race being close is if I opt to fill the tank with 103: if the other car looks like a tough race, I want that additional 40 HP

 

You're not serious are you?

The simple answer is no

 

Yeah, I'm very serious.The problem with a simple answer, particularly in this case, is that the answer is neither yes or no but depends on how much effort the owner wants to go to. A stock car won't give you the extra power. But any vette owner canhave the ECM limits expanded/re-tuned so the engine will respond to higher octane gas, and pick up some power. It's inexpensive and if you plan to use the better gas, additional HP and MPG, too.

 

100% go with the premium. period, nuff said
you drive a 2004 corvette, how do want it to run????