What is the lowest octane we dare use in these?/// What about 89.5 w/ Ethanol! It would keep me from having to add any gasline antifreeze!!!! Gets toooo Cold up here!!!!!!

 

last time i bought race gas the pricing wwas somewhere around this.
103 was 5.75 per gallon
105 was 6.50
107 was 7.75
113 ( or 112, i can't remember which) was like 9.75 per gallon
and 117 was like 12.50
so no, there really isn't any resonability ( i think i made that word up) in using that as a daily driver, but my point was that yes the car will handle it...

 

some info on octane. the reason the suggest the octane ratings they do is because this is where the timing for the car is set for optimal performance although higher octane rating can be used it may not give any power adding results all but in the sotp dyno.


Octane rating
The most important characteristic of petrol is its Research Octane Number (RON) or octane rating, which is a measure of how resistant petrol is to premature detonation ( knocking ). It is measured relative to a mixture of isooctane (2,2,4-trimethylpentane) and n- heptane . So an 87-octanepetrol has the same knock resistance as a mixture of 87% isooctaneand 13% n-heptane.

There is another type of Octane, called "Motor Octane Number" (MON), which is a better measure of how the fuel behaves whenunder load. Its definition is also based on the mixture of isooctane and n-heptane that has the same performance. Depending onthe composition of the fuel, the MON of a modern petrol will be about 10 points lower than the RON. Normally fuel specificationsrequire both a minimum RON and a minimum MON.

In most countries (including all of Europe and Australia ) the 'headline' octane that would be shown on the pump is the RON: but in the [United States] and someother countries the headline number is in fact the average of the RON and the MON, sometimes called the "Road Octane Number" orDON. Because of the 10 point difference noted above this means that the octane in the [United States] will be about 5 pointslower than the same fuel elsewhere: 87 octane fuel in the [United States] would be 92 in Europe

It is possible for a fuel to have a RON greater than 100. This reflects the fact that isooctane is not the mostknock-resistant substance available. Racing fuels, Avgas and LPG typically have octane ratings of 110 or significantlyhigher.

It might seem odd that fuels with higher octane ratings burn less easily, yet are popularly thought of as more powerful. Usinga fuel with a higher octane allows an engine to be run at a higher compression ratio without having problems with knock. Compression is directly related to power, soengines that require higher octane usually deliver more power. Some high-performance engines are designed to operate with acompression ratio associated with high octane numbers, and thus demand high-octane petrol. It should be noted that the poweroutput of an engine also depends on the energy content of its fuel, which bears nosimple relationship to the octane rating.

 

more info on octane sorry for the long read

Are you tempted to buy a high octane gasoline for your car because you want to improve its performance? If so, take note: the recommended gasoline for most cars is regular octane. In fact, in most cases, using a higher octane gasoline than your owner's manual recommends offers absolutely no benefit. It won't make your car perform better, go faster, get better mileage or run cleaner. Your best bet: listen to your owner's manual.

The only time you might need to switch to a higher octane level is if your car engine knocks when you use the recommended fuel. This happens to a small percentage of cars.

Unless your engine is knocking, buying higher octane gasoline is a waste of money, too. Premium gas costs 15 to 20 cents per gallon more than regular. That can add up to $100 or more a year in extra costs. Studies indicate that altogether, drivers may be spending hundreds of millions of dollars each year for higher octane gas than they need.

What are octane ratings?

Octane ratings measure a gasoline's ability to resist engine knock, a rattling or pinging sound that results from premature ignition of the compressed fuel-air mixture in one or more cylinders. Most gas stations offer three octane grades: regular (usually 87 octane), mid-grade (usually 89 octane) and premium (usually 92 or 93). The ratings must be posted on bright yellow stickers on each gasoline pump.

What's the right octane level for your car?

Check your owner's manual to determine the right octane level for your car. Regular octane is recommended for most cars. However, some cars with high compression engines, like sports cars and certain luxury cars, need mid-grade or premium gasoline to prevent knock.

How can you tell if you're using the right octane level? Listen to your car's engine. If it doesn't knock when you use the recommended octane, you're using the right grade of gasoline.

Will higher octane gasoline clean your engine better?

As a rule, high octane gasoline does not outperform regular octane in preventing engine deposits from forming, in removing them, or in cleaning your car's engine. In fact, the U.S. Environmental Protection Agency requires that all octane grades of all brands of gasoline contain engine cleaning detergent additives to protect against the build-up of harmful levels of engine deposits during the expected life of your car.

Should you ever switch to a higher octane gasoline?

A few car engines may knock or ping - even if you use the recommended octane. If this happens, try switching to the next highest octane grade. In many cases, switching to the mid-grade or premium-grade gasoline will eliminate the knock. If the knocking or pinging continues after one or two fill-ups, you may need a tune-up or some other repair. After that work is done, go back to the lowest octane grade at which your engine runs without knocking.

Is knocking harmful?
Occasional light knocking or pinging won't harm your engine, and doesn't indicate a need for higher octane. But don't ignore severe knocking. A heavy or persistent knock can lead to engine damage.

Is all "premium" or "regular" gasoline the same?

The octane rating of gasoline marked "premium" or "regular" is not consistent across the country. One state may require a minimum octane rating of 92 for all premium gasoline, while another may allow 90 octane to be called premium. To make sure you know what you're buying, check the octane rating on the yellow sticker on the gas pump instead of relying on the name "premium" or "regular."

 

...and German gasoline was typically 3-4 times more expensive than American gasoline when I lived there. I guess race gas over there is for really special occasions!!!

 

Different fuel suppliers have different fuel additives and octane ratings. You have research and motor octane, pump octane is a combination of addiding the 2 together and dividing by to, R+M/2. Research octane is a "bogus" measurement achieved in a lab undercircumstances that no car operates under, motor is a more practical number. Say you buy 90 octane pump gas you can have say 100 research and 80 motor which averages 90, or a research of 95 and motor of 85 which also averages 90. However the higher 85 motor will be a better fuel for cars requiring a higher octane.

If you need something really high, I sell a additive that raises 5 gallons of 93 octane to 107, 10 gallons to 104 and 20 to 97, its a unleaded formula and I use it in my turbo car to 25 psi with the 5 gallon ratio. Anyway thats my .02 on the fuel issue.

 

Around here the good stuff is $5 a gallon. I run Sunoco Ultra 94 in my SRT-4 and 110 CAM2 in my Roadrunner. The 110 octane leaded CAM2 race gas and the 100 octane unleaded CAM2 race gas both go for $5 a gallon.

 

I pay 1.80 or so for 91 premium and 1 can of Accelerator 13.00 for 102 octane total cost for 10 gallons of 104 octane.....$31.00

Isnt it amazing unleaded is so much more expensive than leaded fuel for similar octane ratings?