Crown

I can only find 91 octane premium fuel in the island where I live.  My Porsche states that premium 93 octane minimum fuel should be used Ron+mon/2.  

Could this damage my car? I know I have a knock sensor, but still worried...

I am letting my fuel tank get to 1/2 full level, and them I am refilling it with a bottle of octane booster + the dumb 91 premium octane fuel.  Am I wasting my time doing this?

2011 Porsche Carrera 4S Platinum Silver
2013 Porsche Panamera GTS Basalt Black

“The greatness of a man is not in how much wealth he acquires, but in his integrity and his ability to affect those around him positively” 
― Bob Marley

93 octane US equals 98 octane in Germany. This is the recommended fuel quality to achieve the power and torque according to specs.

You are fine with 91 octane US but you need to be aware that you probably loose a couple of horses and some torque in the process. Most people won't even notice though. Be careful with octane boosters, they usually don't even work and they can interfere with the fuel additive some larger fuel manufacturers are adding to their fuel.

No, 91 octane US can't damage your car, your engine has cylinder selective knock sensors.

Just make sure that the fuel quality doesn't drop below 90 octane US (95 octane in Germany).

Also make sure that the fuel doesn't have more than 10% ethanol by volume!!! (E85 fuel for example...a no-go).

Use only brand name fuels if you can't get 93 octane US in your region, avoid no brand name fuel stations (not sure if these exist in the US but over here, we have tons of them).

If the engine starts stalling from time to time or it doesn't start immediately, change the fuel station.

RC (Germany) - Rennteam Editor Porsche Panamera Turbo S, BMW X5M, Mercedes C63 AMG Coupe PP/DP, Mini Cooper S Countryman All4

Ok! That is good advice!

2011 Porsche Carrera 4S Platinum Silver
2013 Porsche Panamera GTS Basalt Black

“The greatness of a man is not in how much wealth he acquires, but in his integrity and his ability to affect those around him positively” 
― Bob Marley

2011 Porsche Carrera 4S Platinum Silver
2013 Porsche Panamera GTS Basalt Black

“The greatness of a man is not in how much wealth he acquires, but in his integrity and his ability to affect those around him positively” 
― Bob Marley

My pleasure.  

RC (Germany) - Rennteam Editor Porsche Panamera Turbo S, BMW X5M, Mercedes C63 AMG Coupe PP/DP, Mini Cooper S Countryman All4

Christian, here is something from AAA regarding the difference between brand name gas and non brand. In short, little to no difference.3.

My gas isn t better for your car; it s just more expensive.

Oil companies spend lots of money explaining why their gas is better than the competition s. Chevron s gas, for example, is fortified with Techron, and Amoco Ultimate is supposed to save the planet along with your engine. But today more than ever, one gallon of gas is as good as the next.

True, additives help to clean your engine, but what the companies don t tell you is that all gas has them. Since 1994 the government has required that detergents be added to all gasoline to help prevent fuel injectors from clogging. State and local regulators keep a close watch to make sure those standards are met; a 2005 study indicated that Florida inspectors checked 45,000 samples to ensure the state s gas supply was up to snuff, and 99 percent of the time it was. There s little difference between brand-name gas and any other, says AAA spokesperson Geoff Sundstrom.

What s more, your local Chevron station may sell gas refined by Shell or Exxon Mobil. Suppliers share pipelines, so they all use the same fuel. And the difference between the most expensive brand-name gas and the lowliest gallon of no-brand fuel? Often just a quart of detergent added to an 8,000-gallon tanker truck.

So it's all just clever advertising?  Interesting... 

That makes sense because there was an oil refinery in the island of St Lucia that closed recently and now all the companies (shell, texaco, total) now only carry 91 octane, that just means they all come from the same place/distributor

2011 Porsche Carrera 4S Platinum Silver
2013 Porsche Panamera GTS Basalt Black

“The greatness of a man is not in how much wealth he acquires, but in his integrity and his ability to affect those around him positively” 
― Bob Marley

ag23...Mira.....https://www.facebook.com/rssracefuels

nberry:

Christian, here is something from AAA regarding the difference between brand name gas and non brand. In short, little to no difference.3.

My gas isn t better for your car; it s just more expensive.

Oil companies spend lots of money explaining why their gas is better than the competition s. Chevron s gas, for example, is fortified with Techron, and Amoco Ultimate is supposed to save the planet along with your engine. But today more than ever, one gallon of gas is as good as the next.

True, additives help to clean your engine, but what the companies don t tell you is that all gas has them. Since 1994 the government has required that detergents be added to all gasoline to help prevent fuel injectors from clogging. State and local regulators keep a close watch to make sure those standards are met; a 2005 study indicated that Florida inspectors checked 45,000 samples to ensure the state s gas supply was up to snuff, and 99 percent of the time it was. There s little difference between brand-name gas and any other, says AAA spokesperson Geoff Sundstrom.

What s more, your local Chevron station may sell gas refined by Shell or Exxon Mobil. Suppliers share pipelines, so they all use the same fuel. And the difference between the most expensive brand-name gas and the lowliest gallon of no-brand fuel? Often just a quart of detergent added to an 8,000-gallon tanker truck.

 

Interesting...especially since a german automobile club came to the same conclusion. Until an independent test actually showed that the quality brands had a higher octane rating than the no-name brands, usually by 1-2 points and that no-name brands can be from the same source but usually aren't, making the name brands better because of the additives(which weren't present in the no-name fuels but of course all of them had basic "cleaning" detergents). Bottom line of the test was: If you are looking for maximum power, go for name brands, if you don't care about a couple of horses up or down, the no-name fuel is good as well.

Now: Take my Panamera Turbo S for example. 550 hp on paper. Shave off 5% of the power, this is what you loose aprox. from going from 98 to 95 octane fuel and this results in 22.5 hp. Sorry but I prefer to pay a couple of cents per liter more to keep the power "stable". I also use high octane fuel on high performance engines because especially on turbo charged cars, high octane fuel can maintain a higher engine power output at higher operating temperatures. So I use Shell V-Power Racing which is claimed to have minimum 100 octane RON but in reality has been tested in various tests between 102 and 104 octane. The knock sensor of my Turbo S is adapted to 98 octane, indeed but under extreme conditions, like the hot operating temperatures like I mentioned, the higher octane fuel provides an advantage.

We are car nuts here, Nick...every additional hp or every not lost hp counts.

P.S.: Are you sure your wife didn't steal your Rennteam account lately? Honda instead of Ferrari...condo in Miami instead of a Panamera Turbo S...something is wrong.

RC (Germany) - Rennteam Editor Porsche Panamera Turbo S, BMW X5M, Mercedes C63 AMG Coupe PP/DP, Mini Cooper S Countryman All4

JimFlat6:

ag23...Mira.....https://www.facebook.com/rssracefuels

I hope they offer unleaded 100 octane "race" fuel because some race fuel is leaded.

Also be prepared to pay a huge premium as far as I heard. Over here in Germany, the Shell V-Power 100 octane RON minimum (more likely 102-104 octane...which translates into 107-109 octane US ) costs only 10-15 Euro Cents more than the 98 octane "regular" premium fuel called Super Plus (mandatory for Porsche cars over here, unless you accept less power) but in the US, race fuel seems to cost a lot (not sure if this photo is real though).

RC (Germany) - Rennteam Editor Porsche Panamera Turbo S, BMW X5M, Mercedes C63 AMG Coupe PP/DP, Mini Cooper S Countryman All4

Since I am currently employed in the oil industry (Mineralölen Produktumschlag) I know first hand that fuels at gas stations are the same across the board. The are the same for the simple reason in that they all buy from the same source.. It's just name branding and advertising as well as locations of gas stations, customer services etc etc which makes them justify making you pay more. It's along the same idea that you generally pay 0.02 more for a Liter at a Shell along the Autobahn, over one in the city.

Yep Nick is right

Could it be that better names in the fuel industry add their own additives to the otherwise identical basic fuel? If so this could make a difference.

--

"Form follows function"

It is unleaded race gas.

I found this gas station yesterday and filled my tank at $2.62 per liter of fuel!!!!! Not fun, but I feel my car running better... 

2011 Porsche Carrera 4S Platinum Silver
2013 Porsche Panamera GTS Basalt Black

“The greatness of a man is not in how much wealth he acquires, but in his integrity and his ability to affect those around him positively” 
― Bob Marley

you can use toluene to raise the octane of your fuel. that is what petrol companies actually do.

reginos:

Could it be that better names in the fuel industry add their own additives to the otherwise identical basic fuel? If so this could make a difference.

That is exactly why branded fuels are superior to supermarkets.  Shell V-Power is the way to go..

"Things turn out best for people who make the best of the way things turn out."

reginos:

Could it be that better names in the fuel industry add their own additives to the otherwise identical basic fuel? If so this could make a difference.

--

"Form follows function"

Exactly. Despite the fact that I can't find any fuel above 98 octane at no-name stations.

Turbo engines should always use the best fuel quality possible, unless of course you have tweaked your engine ECU to lower quality fuel. There are also low compression engines available (yes, Porsche) for specific regions in the world where only low octane rating fuel is available.

RC (Germany) - Rennteam Editor Porsche Panamera Turbo S, BMW X5M, Mercedes C63 AMG Coupe PP/DP, Mini Cooper S Countryman All4

intouch1:

you can use toluene to raise the octane of your fuel. that is what petrol companies actually do.

Yes but you need a 20-30% concentration for being effective (2.5 to 3 points octane rating increase).

There are actually octane boosters which come close to that without that huge amount of liquid.

Octane boosters are really only for regions, where high quality fuel isn't available.

If you can put your hands on 98 octane (93 octane US) fuel, you're good.

RC (Germany) - Rennteam Editor Porsche Panamera Turbo S, BMW X5M, Mercedes C63 AMG Coupe PP/DP, Mini Cooper S Countryman All4

ag23:

I found this gas station yesterday and filled my tank at $2.62 per liter of fuel!!!!! Not fun, but I feel my car running better... 

Ouch. I paid 1.72 EUR for one liter of V-Power with 100 octane minimum (105 octane US). This is aprox. 2.13 USD.

V-Power is widely available in Germany, Austria and other EU countries at almost every Shell fuel station and we also have Aral with Ultimate 102 which has at least 102 octane.

Various tests have proven that mostly turbo charged engines profit from higher octane fuel, not necessarily N/A engines. The power increase was in the 2-3% range at max on N/A engines, usually even less but up to 5% on turbo charged engines. Unfortunately the fuel companies promise increases of up to 10%, which isn't really accurate.

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RC (Germany) - Rennteam Editor Porsche Panamera Turbo S, BMW X5M, Mercedes C63 AMG Coupe PP/DP, Mini Cooper S Countryman All4

Sorry Christian, that dog will not hunt. It is the same gas. Now some oil companies may claim they add additives for cleaning purposes but it is the same gas. BTW, I doubt VERY MUCH you could tell whether the octane was a point or two lower in octane. Aaron thanks for the information but even on this site facts get ignored for opinion.

FWIW, Ben and I filled his CGT with special racing fuel (I think it was around $12 a gallon) and really put it through the spirited and aggressive driving. He drove and then I drove so that we could feeling the car from the driver and passenger seats. We both agreed there was little to no difference in performance. So Christian save your money and fill up at a no brand station.

However, you are right about one thing. I am down on super performance cars for now. I just don't see any upside to them. Unless you track them there really is no where to use it even at 50% of its potential. It is like a one arm guy buying a piano. Also, if you are racing or driving at very high speeds and someone is injured, the owner driver could be facing criminal charges. Finally, factor in the cost of the car and my feeling about super sport cars, at least for now, is duh dumb and stupid. 

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My query and consternation is that it's impossible for us to discern, at the point of purchase, whether or not super-unleaded is actually being dispensed at the relevant pump or whether the station is ripping us off by selling standard unleaded at an inflated price..

Although I always purchase from the super (98 Ron) pump, I have sometimes noticed a reduced performance from fuel dispensed at some stations!  It would be so easy for them to do this and how would we be able to tell at the time we fill up..

"Things turn out best for people who make the best of the way things turn out."

Number one assurance, the delivery driver would only drop the fuel to the appropriate tank at the risk of his job and major fines otherwise.

It is true that the terminal is usually supplied from a pipeline which carries only one fuel. It is the same for all stations and even all octane levels. It is the quantity and quality and to some extent the blending method used for the additives that makes all the difference. The brand names command a higher price for a good reason.

John H:

My query and consternation is that it's impossible for us to discern, at the point of purchase, whether or not super-unleaded is actually being dispensed at the relevant pump or whether the station is ripping us off by selling standard unleaded at an inflated price..

Although I always purchase from the super (98 Ron) pump, I have sometimes noticed a reduced performance from fuel dispensed at some stations!  It would be so easy for them to do this and how would we be able to tell at the time we fill up..

There could be other reasons for this, for example I always stop at gas stations that get a lot of movement, so that the station's gas tank is refilled constantly, on some slower stations, the 98 Ron gas particularly sits for long in the stations tank and goes "stale" since they don't sell that much of it compared to the others. This is especially evident for aircooled 911's to the point of stalling and having problems. And its the slower stations that give those problems.

Also if you see the fueling truck in the station, skip to the next one, the station tanks are filthy on the bottom and when they are refuled, it all gets mixed and in suspention until it gets settled on the bottom after a while, and you can pump that into your car.

I simply never stop and no-brand stations because I simply don't trust them, if they get the gas from the same source, were do they cut the corners to be able to afford such low prices? its a lot more probable to find issues in those non-brand stations than regular stations. Not worth the gamble IMO.

A guy from the automotive industry once told me some time ago that there is no point to tank more than 98Octane. The engine (electronic) is designed for a maximum of 98 octane. More octane is not recognized by electronics, the engine is running in the 98 octane mode.

Quote: "It's like a 18-year-old guy drinking old Bordeaux red wine. A simple Chianti, for him it tastes also good, he also gets drunk, but it saves a lot of money "

I don’t know if modern Porsche changed the electronics.

And we all change our cars every 2-4 years. I don’t believe that you have more trouble with your car if you use normal (=recommended) fuel in that period.

Itsme:

A guy from the automotive industry once told me some time ago that there is no point to tank more than 98Octane. The engine (electronic) is designed for a maximum of 98 octane. More octane is not recognized by electronics, the engine is running in the 98 octane mode.

Quote: "It's like a 18-year-old guy drinking old Bordeaux red wine. A simple Chianti, for him it tastes also good, he also gets drunk, but it saves a lot of money "

I don’t know if modern Porsche changed the electronics.

And we all change our cars every 2-4 years. I don’t believe that you have more trouble with your car if you use normal (=recommended) fuel in that period.

This is true for most N/A engines but not for turbo charged engines.

It also depends on the ECU used, there are systems which adapt to fuel quality, even higher than 98 octane and others don't. There have been extensive tests regarding this but higher octane fuel usually makes sense mostly on turbo charged and/or tuned cars. Porsche uses a Siemens ECU on my Turbo S and I know for a fact that the EMS SDI 6.1 can adapt pretty well to lower and even better fuel quality, especially on Turbo charged engines.

Just an example: Put a turbo charged engine on a dyno at 30°C air temperature and then at 10°C. The power output will be substantially lower at 30°C. Now using high octane fuel prevents the drop because the knock sensor still uses the fuel at full extent. I can't explain it technically, English isn't my mother language but an engineer once it explained it to me. Same goes to larger intercoolers, which don't provide necessarily more power but help to keep the power level steady even at higher operating temperatures.

It is also possible to change the engine software mapping to benefit from the usage of higher octane fuel but thats a different story.

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RC (Germany) - Rennteam Editor Porsche Panamera Turbo S, BMW X5M, Mercedes C63 AMG Coupe PP/DP, Mini Cooper S Countryman All4

nberry:

Sorry Christian, that dog will not hunt. It is the same gas. Now some oil companies may claim they add additives for cleaning purposes but it is the same gas. BTW, I doubt VERY MUCH you could tell whether the octane was a point or two lower in octane. Aaron thanks for the information but even on this site facts get ignored for opinion.

I can feel a 20-30 hp difference, especially in the higher rev range.

20-30 hp less (using 95 octane fuel for example on my Turbo S instead of 98 octane) would mean 0.5 seconds longer from 0-200 kph and probably 2 seconds from 0-300 kph. While this may not be important for you, Honda and speed limit and all... , it is very important to me. 

If the 100 octane fuel would cost double the price, I wouldn't use it. Even at 50% more, I would have my doubts.

Right now, I pay around 10-12 Euro Cents more for the 100 octane fuel (compared to the 98 octane fuel), so this really doesn't bother me.

No, it is not the same gas because I can't get 100 octane at no-name fuel stations. 

You should also know that Porsche for example, always tests various fuel qualities during development, incl. the high octane fuels. The only reason Porsche doesn't explicitly recommend this fuel is mainly for environmental reasons. The government over here wants people to use the E10 fuel, which has ethanol added.

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RC (Germany) - Rennteam Editor Porsche Panamera Turbo S, BMW X5M, Mercedes C63 AMG Coupe PP/DP, Mini Cooper S Countryman All4

John H:

My query and consternation is that it's impossible for us to discern, at the point of purchase, whether or not super-unleaded is actually being dispensed at the relevant pump or whether the station is ripping us off by selling standard unleaded at an inflated price..

The risk of this happening is much higher at no-name fuel stations.

I watched a couple of times how the fuel gets delivered to the brand name Shell station over here: A Shell truck is coming and the driver(!) is doing all the work, the owner of the fuel station just needs to push some buttons, etc. but the driver does the fill up job, so I doubt they would cheat. Also all brand name fuel stations over here are actually franchise companies.

RC (Germany) - Rennteam Editor Porsche Panamera Turbo S, BMW X5M, Mercedes C63 AMG Coupe PP/DP, Mini Cooper S Countryman All4

reginos:

Could it be that better names in the fuel industry add their own additives to the otherwise identical basic fuel? If so this could make a difference.

--

"Form follows function"

That's exactly what happens - SWMBO's job is in the UK's largest oil refinery so she knows the real story and  your reasoning is correct and why supermarket fuels are inferior to premium brand fuels. Shell VPower, BP Ultimate, Exxon 98 is the way to go. I'd much rather put regular octane premium brand fuel in the tank than even high octane supermarket fuel.

It's not that budget fuel will damage the engine (it won't) but performance will go down and fuel consumption will increase. Used over a prolonged period the cheaper brands will cause more problems as they lack the premium cleaning additives that keep the high precision fuel injection components clean. This will also eventually foul valve seats and guides and turbocharger rotors.

Don't get overly hung up on the high octane debate  - although preferable the quality of the basic fuel is far more critical.

Would you put cheap lubricating oil in the engine? No? So don't use cheap fuel! Nearly as silly as using cheap tyres.........

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Everybody is a genius. But if you judge a fish by its ability to climb a tree it will live its whole life believing that it is stupid. - Albert Einstein

Porsche 997 Carrera S PDK Aqua Blue / Black - Toyota Yaris D4D  "Clockwork Rat"

It also depends on the ECU used, there are systems which adapt to fuel quality, even higher than 98 octane and others don't. There have been extensive tests regarding this but higher octane fuel usually makes sense mostly on turbo charged and/or tuned cars.

Sorry, an engineer working on engine development told me that no car has an (original) ECU which adapts more than 98 octane. Maybe now ECU versions has changed, my information is 4-5years old.

Just an example: Put a turbo charged engine on a dyno at 30°C and then at 10°C. The power output will be substantially lower at 30°C.

Yes

Now using high octane fuel prevents the drop because the knock sensor still uses the fuel at full extent. I can't explain it technically, English isn't my mother language but an engineer once it explained it to me.

Possible, I don’t have any knowledge/infomation about this case

Same goes to larger intercoolers, which don't provide necessarily more power but help to keep the power level even at higher operating temperatures.

Yes

It is also possible to change the engine software mapping to benefit from the usage of higher octane fuel but thats a different story.

Yes different story

Like I said before, there is a difference in power, most ECU units are not "stuck" at 98 octane but programmed to avoid damage to the engine, knock sensors and all.

The power gain is usually very small though. Fuel manufacturers claim up to 10%, testing showed values around 2-3% on N/A engines and around 5% on turbo charged engines.

Now, take a N/A engine with 300 hp and 2-3% are up to 9 hp. Ridiculous, indeed.

Take my Turbo S engine and 5% are already 22.5 hp on paper. Not a huge gain but already interesting.

Now if we suppose that the Turbo S actually produces 600 hp and more in reality(at least those cars having a 0-200 kph performance under 12 seconds ), 5% are already 30 hp more. 

For 10-12 Euro Cents more per liter, not really an issue for me. .. 

Like I also said before, I would never pay double the price or even a 50% premium for this kind of fuel though.

RC (Germany) - Rennteam Editor Porsche Panamera Turbo S, BMW X5M, Mercedes C63 AMG Coupe PP/DP, Mini Cooper S Countryman All4