Gas ⛽️

[Slip_Angle]

My point exactly. The S4 owner engine requires 91 or better fuel. His engine gained more power with 94 octane as expected. Modern engines usually reduce timing as the rpms increase past a point or at WOT especially force inducted engines, so it may not be a fuel quality issue; but just how the engine runs normally. However, higher octane reduces the need for reduced engine retard as the rpm increases; hence again why 94 octane created more power.

91 or better, means the engine runs better as the octane increases as was the case for the S4 owner dyno results.

Well, not really. He had a 92 octane outperform a 94 octane fuel. I understand how timing works and when you have a tuned ECU, you can increase timing and boost to suite higher octanes. That is well understood.

What I'm saying is that in a factory stock ECU timing and boost will be set to capped levels. So let's say the G70 makes 365hp and 400ft/lbs maximum at 12psi and 15 degrees of timing -- provided there is no knock. If you put in 87 octane and there is no knock, you will reach target power figures. If you put in 91 octane, you will reach 12psi and 15 degrees BUT since the higher octane fuel burns slower, you won't reach the 365hp and 400ft/lbs. If the engine knocks with lower octane, then yes all bets are off and you need a higher octane fuel.

I did some testing on my G70 over the span of several months and with 3 different fuels and octane levels. My car ran it's best 0-60 times using 87 octane. 91 and 93 were consistently slower. Now there are holes in my experiment, I will admit. Different brands, days etc... but overall the results were consistent.

Here is an article explaining what I mean...

Octane vs. Horsepower - Separating fact from myth in the debate over which fuel makes more power - NASA Speed News Magazine

 

[EdP]

Well, not really. He had a 92 octane outperform a 94 octane fuel. I understand how timing works and when you have a tuned ECU, you can increase timing and boost to suite higher octanes. That is well understood.

What I'm saying is that in a factory stock ECU timing and boost will be set to capped levels. So let's say the G70 makes 365hp and 400ft/lbs maximum at 12psi and 15 degrees of timing -- provided there is no knock. If you put in 87 octane and there is no knock, you will reach target power figures. If you put in 91 octane, you will reach 12psi and 15 degrees BUT since the higher octane fuel burns slower, you won't reach the 365hp and 400ft/lbs. If the engine knocks with lower octane, then yes all bets are off and you need a higher octane fuel.

I did some testing on my G70 over the span of several months and with 3 different fuels and octane levels. My car ran it's best 0-60 times using 87 octane. 91 and 93 were consistently slower. Now there are holes in my experiment, I will admit. Different brands, days etc... but overall the results were consistent.

Here is an article explaining what I mean...

Octane vs. Horsepower - Separating fact from myth in the debate over which fuel makes more power - NASA Speed News Magazine

I think it goes back decades when engines did not have the electronics to adjust anything. The typical sedan used regular gas. The big powerful V-8s had high compression and needed premium. Therefore, premium gas has more power.
sixty years later people still think that way.

 

[carguy75]

Well, not really. He had a 92 octane outperform a 94 octane fuel. I understand how timing works and when you have a tuned ECU, you can increase timing and boost to suite higher octanes. That is well understood.

What I'm saying is that in a factory stock ECU timing and boost will be set to capped levels. So let's say the G70 makes 365hp and 400ft/lbs maximum at 12psi and 15 degrees of timing -- provided there is no knock. If you put in 87 octane and there is no knock, you will reach target power figures. If you put in 91 octane, you will reach 12psi and 15 degrees BUT since the higher octane fuel burns slower, you won't reach the 365hp and 400ft/lbs. If the engine knocks with lower octane, then yes all bets are off and you need a higher octane fuel.

I did some testing on my G70 over the span of several months and with 3 different fuels and octane levels. My car ran it's best 0-60 times using 87 octane. 91 and 93 were consistently slower. Now there are holes in my experiment, I will admit. Different brands, days etc... but overall the results were consistent.

Here is an article explaining what I mean...

Octane vs. Horsepower - Separating fact from myth in the debate over which fuel makes more power - NASA Speed News Magazine

The 92 was from the US, so Canadian gas quality was also a factor in the test. My point is focused on the Canadian fuel tests. 94 beats the 91 as expected. I would assume my local Shell 93 would probably do well in that test as well based on Canadian fuel quality.

If you believe that 87 octane runs better than go for it. This debate has been done before I was born so I doubt I will change your mind. My point is that the video really only proves that more octane provides more power in a turbo engine in regard to local fuels and that gas quality matters as well.

Note: The Volvo engine in that link only has a 8.8:1 compression. That is very low; so yes it will lose power with 91 octane fuel. High compression engines(usually 10:1 or higher) or force inducted engines gain power from 91 or higher octane fuels like stated in the owners manual(5.0 and 3.3T) in our cars except the 3.8 V6.

 

[carguy75]

I think it goes back decades when engines did not have the electronics to adjust anything. The typical sedan used regular gas. The big powerful V-8s had high compression and needed premium. Therefore, premium gas has more power.
sixty years later people still think that way.

LOL. Premium fuel has less energy than regular fuel which allows of a complete compression stroke in the engine without pre-detonation which can damage an engine. A well know fact even in the old days by engine builders, but not by the average consumer.The higher the compression the more need for premium fuel to make peak power without pre-detonation.

Direct injection in our engines allows the cylinders to run cooler and reduce pre-dontation so high compression engines can run safely with regular fuel with a reduction in peak power due to some timing retard when knock is detected(and it will knock). However, the direct injected engine would run at it best with premium fuel not 87 octane.

Regular fuel is more volatile than premium fuel hence why it is never used by any performance oriented engines which uses high compression or force -induction as a rule. Even Hyundai gives reduced power numbers/declaimers for the 5.0 and 3.3T when used with regular fuel.

Regular fuel can be used in our engines, but the engines will run stronger with premium.

 

[Slip_Angle]

The 92 was from the US, so Canadian gas quality was also a factor in the test. My point is focused on the Canadian fuel tests. 94 beats the 91 as expected. I would assume my local Shell 93 would probably do well in that test as well based on Canadian fuel quailty.

If you believe that 87 octane runs better than go for it. This debate has been done before I was born so I doubt I will change your mind. My point is that the video really only proves that more octane provides more power in a turbo engine in regard to local fuels and that gas quality matters as well.

I agree, If quality matters then it's not just octane. See, I don't understand why you say as expected. Maybe assumed is a better word. If you do actual testing, it's not always the case. I can find and provide examples if you want to see more. If you read the article I included, they found the same result. A lower octane can produce more performance. I would love to just put in higher octane and get more power but it doesn't work that way with new electronics....

If you have evidence to the contrary I truly would be happy to see it and change my mind!

 

[Slip_Angle]

The 92 was from the US, so Canadian gas quality was also a factor in the test. My point is focused on the Canadian fuel tests. 94 beats the 91 as expected. I would assume my local Shell 93 would probably do well in that test as well based on Canadian fuel quailty.

If you believe that 87 octane runs better than go for it. This debate has been done before I was born so I doubt I will change your mind. My point is that the video really only proves that more octane provides more power in a turbo engine in regard to local fuels and that gas quality matters as well.

I agree. If quality matters then it's not just octane. See, I don't understand why you say as expected. Maybe assumed is a better word. If you do actual testing, it's not always the case. If you read the article I included, they found the same result. A lower octane produce more performance.

LOL. Premium fuel has less energy than regular fuel which allows of a complete compression stroke in the engine without pre-detonation which can damage an engine. A well know fact even in the old days by engine builders, but not by the average consumer.The higher the compression the more need for premium fuel to make peak power without pre-detonation.

Do you mean pre-ignition? I highly doubt that is occurring. Again, if lower octane fuel has more energy and there is no knock the engine is making more power.... The old days are not relevant anymore.

Direct injection in our engines allows the cylinders to run cooler and reduce pre-dontation so high compression engines can run safely with regular fuel with a reduction in peak power due to some timing retard when knock is detected(and it will knock). However, the direct injected engine would run at it best with premium fuel not 87 octane.

So if DI runs cooler and reduces the chance of knock, then wouldn't 87 have a better chance at no knock? Assuming that and it's higher energy release won't it potentially make more power? The answer is - yes.

Regular fuel is more volatile than premium fuel hence why it is never used by any performance oriented engines which uses high compression or force -induction as a rule. Even Hyundai gives reduced power numbers/declaimers for the 5.0 and 3.3T when used with regular fuel.

Regular fuel can be used in our engines, but the engines will run stronger with premium.

..and more volatile means a bigger explosion. Hyundai says "could" result in less power. That is because under higher ambient conditions, the engine will be hotter and is more likely to know with lower octane.

 

[carguy75]

I agree. If quality matters then it's not just octane. See, I don't understand why you say as expected. Maybe assumed is a better word. If you do actual testing, it's not always the case. If you read the article I included, they found the same result. A lower octane produce more performance.

Do you mean pre-ignition? I highly doubt that is occurring. Again, if lower octane fuel has more energy and there is no knock the engine is making more power.... The old days are not relevant anymore.



So if DI runs cooler and reduces the chance of knock, then wouldn't 87 have a better chance at no knock? Assuming that and it's higher energy release won't it potentially make more power? The answer is - yes.


..and more volatile means a bigger explosion. Hyundai says "could" result in less power. That is because under higher ambient conditions, the engine will be hotter and is more likely to know with lower octane.

Hey I give up. If you really believe that 87 octane is the best choice for your 3.3T engine than go for it.

 

[PMCErnie]

More taste, or less filling? I feel strongly both ways.

 

[rmod]

Interesting thread. The price difference between premium and regular (91 vs 87) around southern Ontario is ~25 cents per litre. I've tried premium vs regular when the car (2.0T) was new and did not feel any difference in performance / mileage in my daily commute. (Maybe the difference is more pronounced on a 3.3 engine and or may be it will show slightly higher numbers if tested on a Dyno). So I've been using 87 for the past 2 years. I use 4 tanks of fuel every month. (25 cents more per litre times 240 litres = $60 = almost one free tank of gas every month).

Apart from the slightly diminished performance, is there any long term damage to the engine?

 

[EdP]

More taste, or less filling? I feel strongly both ways.

Yep, I agree with Trixie86. Mooshead Beer.

______________________________

Help support this site so it can continue supporting you!

 

[Slip_Angle]

Apart from the slightly diminished performance, is there any long term damage to the engine?

Nope and the performance may not be diminished at all..

 

[carguy75]

Interesting thread. The price difference between premium and regular (91 vs 87) around southern Ontario is ~25 cents per litre. I've tried premium vs regular when the car (2.0T) was new and did not feel any difference in performance / mileage in my daily commute. (Maybe the difference is more pronounced on a 3.3 engine and or may be it will show slightly higher numbers if tested on a Dyno). So I've been using 87 for the past 2 years. I use 4 tanks of fuel every month. (25 cents more per litre times 240 litres = $60 = almost one free tank of gas every month).

Apart from the slightly diminished performance, is there any long term damage to the engine?

Using 87 octane should not damage your 2.0T engine. Hyundai design these engines to run on 87 with a slight loss in performance. The power loss is very little in regards to using premium. Maybe about 10 hp or so. Could be more with force induction engines, but no more than 20hp or so I believe.


However, a member claims to lose nothing by using 87 octane in their 3.3T so it may not affect your 2.0T engine at all by using 87 octane. I do not know one way or another to be honest aside from information I read about octane and performance.

Hyundai does state that the 5.0 engine loses about 13hp by using 87 octane over 91 octane. So my engine does lose power when using 87 octane. I actually have no idea about the GDI turbo engines. Common sense based on engine operation tell me that GDI turbo engines does loses power with 87 octane as well.

GENESIS - Hyundai Newsroom

www.hyundainews.com

 

[Slip_Angle]

Using 87 octane should not damage your 2.0T engine. Hyundai design these engines to run on 87 with a slight loss in performance. The power loss is very little in regards to using premium. Maybe about 10 hp or so. Could be more with force induction engines, but no more than 20hp or so I believe.


However, a member claims to lose nothing by using 87 octane in their 3.3T so it may not affect your 2.0T engine at all by using 87 octane. I do not know one way or another to be honest aside from information I read about octane and performance.

Hyundai does state that the 5.0 engine loses about 13hp by using 87 octane over 91 octane. So my engine does lose power when using 87 octane. I actually have no idea about the GDI turbo engines. Common sense based on engine operation tell me that GDI turbo engines does loses power with 87 octane as well.

GENESIS - Hyundai Newsroom

www.hyundainews.com

The one thing about common sense is that it's not common at all.

Empirical testing trump's common sense every time.

 

[carguy75]

The one thing about common sense is that it's not common at all.

Empirical testing trump's common sense every time.

LOL. Tell me about any modern direct injected engine that makes more power with 87 octane as opposed to 91 octane(or higher). BMW, Lexus, Audi,etc all spec(or recommend) premium fuel for their turbo engines to my knowledge. Hell ,even Hyundai makes the same claim about their engines.

No one claims that regular fuel make more power in their direction injection turbo engines or even the same power as premium fuel if regular is allowed. Ford also gives different power ratings based on octane levels for the Eco boost direct injected engines.

You should prove your point with fuel tests as well with dyno numbers as well to prove your point. At the least; you should provide some data logs that include knock sensor data to reinforce your point that 87 octane provides the same performance as 91 octane in your engine. All you give us is information about your times being quicker with 87 octane, but no knock sensor data to clarify if the engine really can run 87 octane without detonation or pre-ignition.

 

[tuckerdog1]

I use the ethanol free. Octane is lower than premium. 92 or 93. Not driving much, so a tank lasts quite awhile. Don't want the ethanol attracting water.

 

[Husky]

Where do you get that? I thought all our gas had ethanol in it.

 

[Slip_Angle]

LOL. Tell me about any modern direct injected engine that makes more power with 87 octane as opposed to 91 octane(or higher). BMW, Lexus, Audi,etc all spec(or recommend) premium fuel for their turbo engines to my knowledge. Hell ,even Hyundai makes the same claim about their engines.

No one claims that regular fuel make more power in their direction injection turbo engines or even the same power as premium fuel if regular is allowed. Ford also gives different power ratings based on octane levels for the Eco boost direct injected engines.

You should prove your point with fuel tests as well with dyno numbers as well to prove your point. At the least; you should provide some data logs that include knock sensor data to reinforce your point that 87 octane provides the same performance as 91 octane in your engine. All you give us is information about your times being quicker with 87 octane, but no knock sensor data to clarify if the engine really can run 87 octane without detonation or pre-ignition.

Listen. Have an open mind. Be a contributor. No one is arguing that you can make more power by increasing ignition timing and putting in a higher octane fuel. That's engine performance 101.. get past it. There are more factors that play a part in this and may explain why I get better results with 87 octane.

1. Ambient air temperature
2. Capped timing (Pre-defined power output)
3. Compression ratio
4. Ethanol content (reduces knock)

Think about it. If 87 octane burns quicker, it produces MORE power when all other conditions are the same vs a higher octane fuel. should one of those conditions (such as heat) change, then the results will be different. Very simple to understand.

In my case, my G70 is posting quicker times using 87 as measured with a Dragy vs higher octane fuels.. Not perfect testing but at lease I am contributing with actual testing data instead of just emphatically stating an arm chair opinion with ZERO testing of your own. If one day I get better times with a higher octane, I will post it. If you want to test and show other results... happy to see them.

It's also a no brainer that modern engines can produce more power on higher octane fuels **if they are designed to**.. by increasing ignition timing... simple... my point is that it's not a clear cut answer to a simple question. There are more factors.

Can the 3.3T in the G70 run 87? Of course it can.. Genesis says it can... does it reduce ignition at times? Guaranteed it does. Especially at higher ambient temps.. and the ecu will correct the ignition timing as it senses knock. It will do the same on 91,92,93 and 94 as well... Normal operation. Light knock is normal and is common. That is how the engine ecu determines timing corrections...

Pre-ignition in such a new DI engine? No. Octane isn't really a factor in pre-ignition.

The information I provided was just that... an interesting data point for discussion. I won't be dyno or fuel testing since I have none of this equipment or care enough to spend the money.

 

[tarhoosier]

In all this discussion is there a risk to the engine using 92 or 93 or whatever the highest standard octane available in my area? Driving in normal conditions, without high rpm launch and so on, can highest octane damage the engine?

 

[EdP]

Where do you get that? I thought all our gas had ethanol in it.

Readily available but at a price. Here is is about 85 cents more but I use it in my generator.

Pure-gas.org - ethanol-free gasoline in the U.S. and Canada

Pure-gas.org is the definitive web site listing stations that sell pure gasoline in the U.S. and Canada.

www.pure-gas.org

 

[EdP]

I use the ethanol free. Octane is lower than premium. 92 or 93. Not driving much, so a tank lasts quite awhile. Don't want the ethanol attracting water.

What do you do with the normal condensation that gets in tanks? Before ethanol we used to put in Dry-Gas as it would pick up the water and pass it through.

Ethanol Does NOT Suck Water Out Of The Air +VIDEO

insidious lies spread by the oil industry about ethanol is that ethanol sucks water right out of the air. Sometimes it's phrased as "it attracts" or "it absorbs" water right out of the air.

www.theautochannel.com