HEY ,IMO..Running that 100 octane is a win win situation except for the price,Since we have turbos and yours is mapped it can only help put you in a better upper timing /boost 'range' OR atleast when it gets hotter it doesnt pull it down...and you are only talking 100 octane not the big octane numbers,but would hurt more so on a non turbo car..,Just sharing my info

 

I feel like I notice a difference when I throw a few gallons of 100 octane in the tank. My car has EVOMsIt tuned for 91 octane. Its nice there is a station that carries 100 only a few miles away.

 

Let’s not forget that not all gas's or high octane numbers are the real deal
Octane is a good place to start when trying to pick the correct gasoline for your vehicle, but there is more to consider.

The octane number is of value when picking a gas to run but it is important to know how that number is derived; if an oxygenated alcohol is used or MTBE. Both yield higher test numbers when testing for octane but they are much less costly then the chemicals that are used in a quality fuel, not even to mention race type fuels.

Pump gas usually contains an oxygenate like ethanol or MTBE. Both are used extensively in pump gasoline to help reduce exhaust emissions but are sold as performance enhancers to an unknowing consumer.

A quality fuel is a balancing act, you want a fuel that vaporizes well and at the right temp; it also has to combust properly. To do that you use better more expensive chemicals and better refinement; only to supply a limited market.

You will never see a pump fuel that is anything special plus delivers consistent quality. But that being said there are some pump gas makers that care more than others about making a better performing premium gas.

 

Which station near you carries 100? I just found one off of 680 in Sunol -- that might be the closest to me.

 

There is a 76 off Almaden Expressway that has it near me. Which exit is the one in Sunol? I see one gas station at the bottom of the sunol grade is that it? I drive by there everyday now on my way to work.

There is a link in the NorCal section that lists all the stations in the area that cary 100 octane. That was how I found the one in Almaden. Who knows if all the places in the thread are accurate since the thread started in 2007.

 

According to the internet -- Sunol Super Gas right off 680 at Andrade. I've read they have 91, 94, 96, 98 and 100. I haven't confirmed in person yet -- let me know if you confirm this.

 

Yeah that's the one I see every day. Next time I take the 996tt into work I'll stop off there and check it out.

 

Actually, I might do a drive by tomorrow -- I didn't realize how close it is to me. Just a few miles North on 680 (I'm off of the North Mission exit). It looks like it's right after the truck scales? I'll let you know what I find out.

 

A couple VP stations have popped up lately as well that sell a variety of race octanes.

RE: the 76 station on Almaden, the VP station is on Camden near Union heading toward HWY 17.

You definitely need the right tune to run higher octanes, else you may risk internal damage. Why do you think the tuners ask what octane you will be running and/or offer twin or triple mapping options.

 

Can you clarify on the risks associated with running higher octanes? My understanding has been that other than higher cost and the slightly lower energy content of higher octane fuel (thus making less power if the motor would run the same timing and boost without it), there is no real downside.

On older turbos with primitive or no knock sensors, higher octane at the track was critical. This was certainly the case with my old 300ZX TT, where the combination of insufficient engine cooling, the PCV system pulling oil in to the intake plenum on high-G turns, and injectors close to their max flow all contributed to risk of a lean condition and preignition. High-RPM knock can destroy an engine in seconds, so running 100 or a mix of 91 and 100 was (relatively) cheap insurance.

I'd love to hear that the knock detection is robust enough and that the cooling/fuel systems in our cars have enough headroom to make this a nonissue. Last time I was at the track I spent $150 on fuel!

 

this is correct.
They even have 110 and E85, FYI

 

1. There is NO RISK using higher octane than your tune was designed to run.

2. Notwithstanding CUSTOM tunes, the real question in this thread is "what can the factory tune utilize?" Empirical data seems to indicate that the stock DME can take advantage of octane up to about 95 (usa, R+M/2). So if you fill 50-50 100 and 91 (california) that is about it.

3. With custom tunes, the tuner sets the 'bottom' to a minimum octane. Say a '100 octane tune' with a min of 97, up to 105.... and you run a tank of 91...bad news... Running 110 or 116 would be OK though, you'd jsut not see the benefit.

 

[quote=jayzbird;3467303] Can you clarify on the risks associated with running higher octanes? My understanding has been that other than higher cost and the slightly lower energy content of higher octane fuel (thus making less power if the motor would run the same timing and boost without it), there is no real downside.

I have always been told NOT to run higher octane levels then what your engine has been designed for, both by car tuners and motorcycle engine builders. I'm not willing to push the envelope and potentially risk a $25k +/- engine rebuild just to say my car runs better. If you want your car to run stronger just pony up and pay for the proper tune. A properly tuned and modified vehicle will always out perform a stock vehicle on running on a higher octane.

"How stuff woks":

The octane rating of gasoline tells you how much the fuel can be compressed before it spontaneously ignites. When gas ignites by compression rather than because of the spark from the spark plug, it causes knocking in the engine. Knocking can damage an engine, so it is not something you want to have happening. Lower-octane gas (like "regular" 87-octane gasoline) can handle the least amount of compression before igniting.

The compression ratio of your engine determines the octane rating of the gas you must use in the car. One way to increase the horsepower of an engine of a given displacement is to increase its compression ratio. So a "high-performance engine" has a higher compression ratio and requires higher-octane fuel. The advantage of a high compression ratio is that it gives your engine a higher horsepower rating for a given engine weight -- that is what makes the engine "high performance." The disadvantage is that the gasoline for your engine costs more.

My advice is run what your manufacturer, tuner, or engine builder recommends, else run at your own risk... therefore, no support when needed in the event of catastrophic failure.

I have run 100 octane in all my race bikes which they were designed and dyno tuned to do so. My buddies with similar builds started bragging about how much better and stronger their bikes were once they used higher level mixtures. Guess what, yes their bikes were stronger for one weekend/race and then the following weekend they would start having problems, including sticky throttles. Third weekend, the bike was in the shop for re-builds. After repeating this sequence several times, they noticed my bike was never requiring any re-builds within a season. They all went back to 100 octane.

Fuel by no means will make you faster. What will make you faster is being smooth, patient, and calculated. Well, unless you're just drag racing...different game.

 

.....agreed.......

 

[quote=VID997;3467658]Hi,IMO you are right with most of what you say..As I use to build ,tune ,race, do dyno shoot outs,design cams on my own dyno for Harleys and back in the days before that high powered Suzukis...BUT what you said is new to me >> Guess what, yes their bikes were stronger for one weekend/race and then the following weekend they would start having problems, including sticky throttles. Third weekend, the bike was in the shop for re-builds. After repeating this sequence several times, they noticed my bike was never requiring any re-builds within a season. They all went back to 100 octane.....I believe there was more to it then just a gas issue..
From what I know,and I dont know everything,Non-turbo vehicles are more prone to power loss with over octane usage then turbos,especially with the turbos electronic range in the controllers also......Just sharing my info....We all learn on here....