Thanks for the advice all. I have never driven a car where a specific octane of fuel is required and so I called the dealership before posting and the guy sounded like I just punched my grandma when I told him. I didn't think it would be an issue but wanted your opinions. I am surprised the guy didn't tell me to hurry in so they can syphon it and charge me. I did learn something new tho. I didn't realize there was a gas thing that you had to put into the hole to let octane booster or a jerry can in

 

All new cars for years have had recommended minimum octane ratings.

Glad your dealer didn't try to screw you and hopefully you now know you can drive it with no worry.

 

The three points you're gaining are 0.1 not 1.0

So adding an octane booster to 87 in appropriate proportions would net you 87.3 not 90, it would take on the order of 2 gallons of the average booster to get to 90 and with the additives in the "boosters" it would run like garbage at that level.

I have a recipe for some gnarly stuff I used to use at the drag track in my old mustang. Awesome stuff it'll easily give you ten points and burns insanely hot, but I think it would render the C7's tank into a puddle.

You'll be absolutely fine.

 

Oh good god you'll ruin the cats & then the engine running 100LL in it & it wouldn't take much either!!

Buy some Torco octane accelerator. I've run quite a few bottles of it & am very pleased with the results.

Wormwood

 

I don't know about you guys but I usually never put more than $40 in at once. For occasions such as this or bad fuel, I'd rather stop at the gas station a little more often than having to drain a full tank of mistake. Call me paranoid but I'd rather be safe than sorry, besides, it gives me a good reason to stop and buy lotto tickets, the Z is coming out soon.

 

Don--Sorry about the bad advice. I believe you are correct. I used to do this many years ago on an early stingray (pre-cat) and it worked well. Thanks for correcting me.

 

That's not quite accurate. Yes, some add 3 or a few more points and yes a point is .1 octane. There is a brand at one of the big auto parts stores that raises the octane 30 points (= 3 octane) for 20 gal. Its safe for cats and is about $13 for a can. It does have a long add-on snout so it works like a charm on our cars.

 

Good advise. Your goal is to burn up the low grade fuel without beating the car. Keep your foot out of the loud pedal and you'll be fine. And don't lug the motor either. Easy does it.

I have an offshore boat with twin supercharged big block Chevys. When it goes into storage I add fuel stabilizer. When it comes out of storage I top off the tanks with no-E fuel high octane and run the motors just short of boost until the tanks are close to empty. Top off with more high octane no-E (not easy to find on the water!) and enjoy!

As for "Miracle in a can" booster et al, save your money. I wouldn't pound my motors with old gas or low octane fuel and "Miracle in a can" under any circumstances.

 

yes it is, and yes it will. One tank of 87 in that car driving it normally will not have any effect on the vehicle what so ever

 

Lighten up Francis. Never suggested using low octane and octane boost as regular fuel.
As for using octane boost, Buick guys and gals been using homemade octane boost for years.

 

I would just take it easy for a bit, run it down, then slosh in the good stuff. You should be fine?

 

If you live close to Fayetteville, Arkansas drive around at light throttle to burn off 3 or 4 gallons and then top off your tank with 98 octane ethanol free Shell gas at the pump, and then hammer it. http://www.hioctanefuel.com/

 

I know I'm putting a target on my back, but here goes anyway.
I tested my 07 C6 at Atlanta Dragway, when I had about 2-3 gallons of 93 octane remaining. Results of 3 runs - about 13.1 et average.
Then added about 5 gal of 87 octane, for a mix of 88 - 89 octane.
The next 3 runs were all in the high 12s. with the best being 12.8 et.

When I bought the Vette new, part throttle response was sluggish (for 400hp). I might describe it as "bogging" when starting slowly. Eventually I tried a full tank of 87 and the bogging disappeared. The engine was much more responsive. Although I didn't hear it, my wife said there was very light pinging, so I switched to 89 octane. Using that fuel, I managed 35.2 mpg for 200 miles on I95 and I4 at 70mph on cruise control and in the summer heat. Double checked that with onboard computer and the manual method by dividing miles/fuel used.

Another controversial statement: Higher octane fuel is not better fuel, it is worse, but sometimes necessary. The additives for raising octane (tetra-ethyl lead, water, etc.) do not burn or produce power, they do the opposite. They slow down burning and raise the ignition temperature, which is necessary in high compression engines, otherwise those engines may get pre-ignition or detonation. The military used to spray water into the fuel mix to raise the octane of high performance aircraft engines.

My wife's Acura TSX advises premium fuel, but says you can use regular. The timing is automatically adjusted, as our Vettes are. Tested on a 2000 mile round trip to Maine, we used premium going up and regular returning. 34mpg on premium and 37mpg on regular. It always gets regular now for the last 7 years and gets great mileage.

Sunoco used to have pumps with an octane selector switch. You could select an octane from 190 to 270 (back then it was measured differently). There were stories of people putting the 270 into their Ford Falcons, just to be "good" to the engine. The result was that the slow burning fuel was still burning when the exhaust valve opened and there were many burned valves. That is where high octane fuel burns hotter. In the exhaust pipe, not in the cylinder. Sunoco quickly eliminated the 270 and 260 was then the highest.
I agree that premium fuel (even the name is a marketing trick) is necessary in high performance engines, but many engines can produce more power and mileage with lower octane fuel. Just don't drive around with your engine constantly pinging.

I wonder if the original poster is still looking?

 

Octane controls the burn rate.. All gasoline has about the same BTUs. Direct injection eliminates hot spots ( from a lean uneven fuel distribution) the LT1 is not that sensitive to octane because it doesn't have fuel distribution problems. Ligtament gasoline companies won't tell you that gasoline gives you more power. What gasoline will do is allow you to make more through higher compression and more advance etc. When NASCAR switched to unleaded they did not use 100 octane but it was 98.

 

Well said, Bill. The burn rate on high octane is slower.
My main point was that many are tricked by marketing people and that "Premium" fuel is not more powerful. It only allows engines to use higher compression ratios. Both the "Regular" and "Premium" contain additives to keep systems clean.
To sum it up, engines that can use lower octanes will develop more power and economy with it.
Think about it. What is the advantage of an ever increasing spark advance? It doesn't do much good to ignite the fuel while the piston is still on its way up. It would be much better to burn it all near TDC, like a diesel. That's not feasible with slow burning gasolines, but it doesn't help to make it even slower burning.
As you said, the C7 solves much of that with direct injection.
Geez - I get too long winded.

 

Not at all, great posts!

I always laugh at the people who swear they can actually feel more power and get lots better gas mileage with higher octane gas. You can't convince them otherwise.