Do you often use high octane fuel?

[Yellow NSX]

Anyone else here also using high octane? If so, I'd be curious to know how much you pay, and if you have experienced any issues.

The only problem I've experienced occurs whenever I fill-up with 93 octane, after running 100. My check engine light is sometimes triggered, signalling a rear O2 or cat/con issue. If I clear the code, however, and continue to use 93 octane - or higher - the engine light does not come back on.

 

[amo]

hi mate i only use 99 octain pay £1.10 a liter
but i have got it mapped on 99 octain as standard is 95 octain in the uk

thx amo

 

[slamstrom]

Have not try 100 octane. Does it taste like chicken?:biggrin:

 

[docjohn]

You are paying 2 more a gallon for placebo fever.If your motor in NA and with only basic mods your ecu does not do much more with 93 vs 100.I have run 100 at the track and I do have slightly faster lap times but due to decrease in weight of my wallet:tongue:

 

[Big_D]

Never put high octane in the tank...91 or 92 thats it. I think its a waste of money unless you need it for a special tune.

 

[nsx1]

Never put high octane in the tank...91 or 92 thats it. I think its a waste of money unless you need it for a special tune.

+1


.

 

[Tom239]

Bear in mind when reading this thread that octane numbers in the USA are not directly comparable to those in Europe as they are measured by different methods.

 

[Yellow NSX]

Never put high octane in the tank...91 or 92 thats it. I think its a waste of money unless you need it for a special tune.

Well, as a result of my four tankful experiment over the past three months, I'm also not convinced running 100 octane provides any noticeable improvement in performance.

That said, paying $5.70 a gallon sure made me feel sorry for drivers living in Europe (and elsewhere) who having been paying such prices for years...

 

[AR]

I use shell V- Power and it runs great!

The Mugen ECU seems to like it.

Cheers,

AR

 

[Vega$ NSX]

Guys, octane does not equal more power. 100 octane gas does not have any more "power" than 89 octane gas. The octane rating only measures the resistance to detonation of the fuel or how much the gas can be compressed before detonation.

So let's examine that in detail for a second. Let's say our NSX requires 91 octane. This is determined by knowing how much air and fuel is mixed (air/fuel ratio) and the compression ratio the car is tuned for. If I require 91 octane, it means, I've tuned the engine to not detonate at the given air/fuel and compression ratio. If I put 89 octane in, then air/fuel and compression ratios will not match the octane. As the gas gets compressed, it will spontaneously ignite before the engine is at proper stroke. When that happens you get detonation and you will hear pinging or knocking which is bad for your engine.

Now on the flip side, if I put 100 octane in, the engine won't generate any more power than at 91 octane. It just means I have greater protection from detonation/knocking/pinging. The car will be running at the same air/fuel and compression ratios so nothing will change. Now, if I retuned the engine to accept the 100 octane (usually done by increasing the air ratio, changing timing and/or compression) then I can take advantage of the increased resistance to detonation and squeeze more power out of the engine. However, that would mean I couldn't go back to 91 octane without fear of detonation/knocking/pinging unless I had an ECU that could reprogram on the fly for different octane ratings. For example, my NSX is turbo boosted and I have a boost controller with a HKS F-Con controller. My tuner (Factor X) tuned my car for different settings for different boost level and octanes. I have a setting that is good for 100 octance race fuel and I'm able to push 14 lbs of boost. However, if I can't get 100 octane, there is a setting I switch to that is good for 91 octane. However, I can only push about 9 lbs of boost and my power output is a lot less. If I were to run 91 octane on the higher boost setting, I would probably detonate and damage my engine. However, if I were to run 100 octane at the lower boost setting then the car would run fine, but only at the lower boost settings and reduced power levels.

The common reason people think increased octane improves performance is because most higher octane (91) cars today have anti-knock sensors. What these cars do is detect knocking/pinging due to low octane fuel and retard the timing, air/fuel ratios etc. among other things to protect the engine. In other words, it retards performance to match the lower octane gas because it is safer to lower the performance than have engine damagine knocking/pinging. But that means the engine is running at partial capacity, which not only robs power, but decreases efficiency and fuel milage. So when the driver then increases the octane, the engine goes back to running at optimal performance. The driver thinks he's getting more performance, because the engine is running at full performance at the correct higher octane, rather than the derated performance at the lower octane.

 

[davidf]

Anyone here know why it smells so good? Funny how a few points in octane can change up the smell.

 

[Yellow NSX]

So let's examine that in detail for a second...

Nice post; very informative. Thx.

 

[s14_tat]

the reason why your throwing check engine codes is because your 02 sensor is probably being fouled up by the lead content in your 100+ octane fuel.

I know that most 110-113 octane race gas are basically leaded fuel, that is why it leaves a white deposit on your tailpipes, and they will also coat your expensive 02 sensor causing them to fail. Unless your running like 12:1 compression pistons or running 15 psi of boost on a GT35R, I wouldn't bother with it.

 

[RON98]

My NSX has become semi-addicted to running on 100 octane (@ $5.70 a gallon...!).

Anyone else here also using high octane? If so, I'd be curious to know how much you pay, and if you have experienced any issues.

The only problem I've experienced occurs whenever I fill-up with 93 octane, after running 100. My check engine light is sometimes triggered, signalling a rear O2 or cat/con issue. If I clear the code, however, and continue to use 93 octane - or higher - the engine light does not come back on.

any reason your using 100 octane instead of the recommend 91/93 depending on your area?

using high octane is not like giving a dog a treat... unless your ignition timing is programmed for 100 octane, then you throwing money away.

octane is as vega$ stated, is the ability of the gas to resist knock. Not only that, higher octane fuel burn slower, thus y more ignition timing advance is needed.

gas company advertise such as regular, plus, advanced.... its only marketing much like putting a fish shape on cat food. cats dont care, its marketing to the owners.

Instead of thinking... regular, plus, advanced... just think does my car match the 87, 89 or the 91 number?

if factory gives me a number of 91. use 91. if it says 87, stick to 87.

91 is not better than 87. its different.

no worries, i use to do the same in my younger days. i would give my civic 91 octane once a week to "keep it happy" :tongue: btw i seriously thought at the time that i got more performance and better gas milage :biggrin:

happy motoring
Rob:smile:

 

[ExCfive]

Thanks "Vega$".....Saved me from writing a longish reply!:biggrin:

 

[ChopsJazz]

Thanks "Vega$".....Saved me from writing a longish reply!:biggrin:

Ditto. It's amazing how many people think octane equals energy.

 

[SweetChuck]

I use 98 octane here in Aus not because of risk of pinging but rather the fact that it contains no ethanol and includes injector cleaners for a healthy engine.

 

[AR]

http://www.shell.com/home/Framework...els/v-power_pkg/benefits/benefits_vpower.html

 

[nsxtasy]

I've tried running 100 octane fuel at the track, and never noticed any significant difference. Now I just get normal everyday premium (even for the track).

 

[johnboy]

any reason your using 100 octane instead of the recommend 91/93 depending on your area?

using high octane is not like giving a dog a treat... unless your ignition timing is programmed for 100 octane, then you throwing money away.

octane is as vega$ stated, is the ability of the gas to resist knock. Not only that, higher octane fuel burn slower, thus y more ignition timing advance is needed.

gas company advertise such as regular, plus, advanced.... its only marketing much like putting a fish shape on cat food. cats dont care, its marketing to the owners.

Instead of thinking... regular, plus, advanced... just think does my car match the 87, 89 or the 91 number?

if factory gives me a number of 91. use 91. if it says 87, stick to 87.

91 is not better than 87. its different.

no worries, i use to do the same in my younger days. i would give my civic 91 octane once a week to "keep it happy" :tongue: btw i seriously thought at the time that i got more performance and better gas milage :biggrin:

happy motoring
Rob:smile:

I,ve always been told to run the lowest oct.you can without detination. You want the charge to born as fast as poss without det. Fast means fast.

 

[Meeyatch1]

I use shell V- Power and it runs great!

The Mugen ECU seems to like it.

Cheers,

AR

I only use Shell V-Power now. I used to think it was all advertising hype until I started noticing that I was getting 50 miles more per tank than I was before, sometimes up to 100 miles more per tank. That additional 5 mpg or so seems to be consistent. My father has since tried the switch in his Acura Legend and noticed the same results of significantly increased mileage and drivability.

 

[pegi]

I use only here in Finland everytime high octane. Here is anyway same what you use, also lower octane is way to go, but I use high octane.:smile:
Sometime also V-power is used in the nsx with somehow better results.

 

[prestonmay]

i use 91 -93 Octane...........i have not noticed a diff in all my cars if i run one or the other....But when i put reg 89 in the rx7.....it runs like crap

 

[NSXGMS]

Anyone here know why it smells so good? Funny how a few points in octane can change up the smell.

Doesn't all gasoline smell good? :wink:

 

[Greg Z]

So you all seem to be saying that the V-power Shell gas gives 5 mp better? Is it really that good?