I just discovered that I drive past a gas station that sells 100 octane gas.

Would there be any harm trying it?

 

if you don't have the plugs gapped correctly and at the right stage, I'd not do it.

The ecu tune needs to be corrected to handle any change in octane, best advice avoid the urge it's only going to cost money and offer 0 benefit.

 

no harm in trying, but it's about the same as throwing your money into the sea. it won't help you anything, coz' the ecu will just burn them like 91 or maybe 93. racing gas is for cars who are tuned for them with heavy modifications. sometimes cars with very high compression and they run into pinging problems with poor CA gas, they can put in say 2-3 gallons of 100 together with 91 to help boost the overall octane to higher for better consumption. but normal use? nah

 

i say give me the price difference your going to spend from 91 to 100 and ill sit in your passenger seat and make bov noises while you drive. you'll feel much faster!

 

srsly

just get this

http://www.youtube.com/watch?v=b9XAC-BvUyo

 

roflmao! too funny!

 

So putting in 2 gallons would boost an almost full 91 octane tank to 92 octane overall. Maybe worth trying to see if there's any improvement.

 

still won't make any difference.

you can't feel the difference between 91 and 92..you probably couldn't feel 20 rwhp either.

but if you are already convinced you wanna do it, there's no stopping you.....at least that's the way I get...when I want something I'm going to do it whether people tell me it's useless or not...so I can't fault you for trying to rationalize your decision.

I can guarantee you no legitimate results...if you want the ultimate waste of money to prove it go on a dyno with 91 then 100....it won't change unless you tune for it.

 

So would I feel the difference between 91 & 89?

 

probably not but its not good to always run the car on 89 or even 87. the thing is you can put 100 in the car if you want but you will not see any difference since the car is not designed to run off 100. you may think its running better but its just a placebo

 

doubtful, the only real difference is IF you get knock, your knock sensor will reduce your timing so you don't get detonation if you use too low of an octane.

keep in mind these companies know damn well you can't get 93 octane across the US, they aren't going to manufacture a car for sale in the US that won't perform optimally at the lowest possible octane rating. they will recommend a high octane because that's what the tune was calibrated for.

 

here's another example of other things that are typically useless.

so apparently you can't retune these cars easily right?
well the car has been tuned for a specific AFR under idle and acceleration, if you change your air intake or exhaust you are just as likely to lose power as gain power b/c the AFR is now thrown off and the ecu can't compensate for that.

If you throw a larger air intake on the car all you've succeeded in is making the car run leaner because more air is now passing by the MAF than was before (if this is a maf car) and now the ECU's applying too little fuel because of unmetered air.

the only benefit to changing ANY component from stock to aftermarket that effects the engine is if you can tune for it, and if you can't you're either spinning your wheels or losing ground.

 

Thanks

While I have quite a few experts on this thread, can I ask about ethanol in fuel and whether you think it's good or bad?

 

A buddy just converted his atom to e85 had to upgrade from 80lb injectors to 96lb injectors, gained 20whp and was a simple retune.

loss in efficiency of at least 20% however, but it's track car and e85 is 1/3 the cost of 110 octane but almost the same octane rating.

based on the feedback that you can't retune the GS, there's no way you could convert then either.

it's a great alternative to race gas....for race cars and track cars.

 

just curious what are you trying to achieve? cheap hp gains?