Gas ⛽️

[Slip_Angle]

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?

No sir!

 

[Trixie86]

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

Ha, used Heet in my 75 Dodge Dart.

 

[Husky]

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

Huh, I must not be paying attention. Every pump I've ever been at just has ethanol added, no other choices. I thought it was mandated. Probably varies by state.
I am aware of True Fuel, and use the two stroke fuel in all my small engines, since they sit all winter, but at over $20/gallon, the four stroke fuel would be prohibitively expensive for a car.

 

[tuckerdog1]

I get the ethanol free at the Quicktrip station here in Georgetown TX. The pump handle is RED, and is not shared with the regular, midgrade & premium that contain ethanol. They share a black pump handle. And of course, there is the GREEN for diesel.

 

[carguy75]

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.

Yes, many factors does come into play. Like you mentioned 87 octane has more energy than 91 octane, however engines makes more power by going through a complete piston stroke. Power production is not based on the energy potential of the fuel alone, but also by complete piston strokes. Regular fuel downfall is that it does not resist compression before igniting which causes the engine to lose power due to a incomplete piston stroke when it does pre-ignite.

Ironically, the high horsepower engines uses fuel with higher octane and lower energy content in high compression setups or force induction setups that also compresses air flow to create power; even in modern direct injection engines. If 87 octane made engine run better(or the same as 91 octane) than engine builders would be all on it due to its energy potential; aftermarket and OEM.

Direct injection does reduces the impact of 87 octane fuel in high compression engines by adding a cooling element to the cylinders that reduces the 87 octane chance of pre-ignition which allows a longer piston stroke, but not like using 91 octane.

Your test is just us taking your word for it with no real comparison logs or data point to refer to. However, we are not scientist with grants to perform proper testing of the interesting theories we come up with; so I understand that you will not spend your own money just to convince anyone on a forum that you may have discovered that the 3.3T runs better with 87 octane.

My 5.0 engine ran like crap with 87 octane in the summer, however it may run better with it in the winter as your theory suggest due to the cooler air further resisting pre-igniton as the piston compress like with 91 octane under the same conditions. However, i still think that 91 octane will run stronger overall even if the engine runs better with 87 in the winter.

I have an open mind, but not a gullible one that believe whatever theory that someone tell me based off the fact that the person claims the car ran a better time and some thread post links that really do not even clarify the person point. Especially if the theory goes against the engineers who created the engine that states otherwise. If Hyundai states that 87 octane gives(or may) reduced performance in their engines; I lean more towards believing them over some guy on a forum.

Page 7 tells it all for the 3.3T and 5.0 engine as well in regard to using 87 octane per the company that built the motors.

https://owners.genesis.com/genesis/us/mygenesis/manuals/glovebox-manual/2019/g70/2019-G70-Owner's-Manual.pdf

 

[carguy75]

Here is an article about 87 octane vs. 91 octane in modern cars. All the cars gained power, but not all the car ran quicker with the premium fuel. The Honda was a tad slower running premium even though premium did increase horsepower, like in your case(slip_angle).

I believe the time difference is just a matter of launching the Honda as opposed to 87 octane causing the car to be quicker. Usually a car is quicker with more horsepower, not slower. Unless traction is an issue.

Is Premium Gas Worth It? We Test High Octane on 4 Popular Vehicles

We tested higher octane fuel than manufacturers require on the Honda CR-V, BMW M5, Ford F-150, and Dodge Charger to see if it impacted acceleration or MPG.

www.caranddriver.com

 

[Slip_Angle]

Yes, many factors does come into play. Like you mentioned 87 octane has more energy than 91 octane, however engines makes more power by going through a complete piston stroke. Power production is not based on the energy potential of the fuel alone, but also by complete piston strokes. Regular fuel downfall is that it does not resist compression before igniting which causes the engine to lose power due to a incomplete piston stroke when it does pre-ignite.

I think what you mean is that the timing of the spark induced combustion event just after TDC is important for max efficiency and power. Technically a piston always has to go through a complete stroke or there will be severe damage to the piston, rods etc... Again, pre-ignition is super unlikely in a new engine like the 3.3T... Pre-ignition happens before spark plug ignition due to abnormal engine issues such as glowing hot carbon deposits, sharp edges, really hot plug etc... The chances of pre-ignition due to lower octane fuel in the 3.3T is pretty much zero.

Ironically, the high horsepower engines uses fuel with higher octane and lower energy content in high compression setups or force induction setups that also compresses air flow to create power; even in modern direct injection engines. If 87 octane made engine run better(or the same as 91 octane) than engine builders would be all on it due to its energy potential; aftermarket and OEM.

Direct injection does reduces the impact of 87 octane fuel in high compression engines by adding a cooling element to the cylinders that reduces the 87 octane chance of pre-ignition which allows a longer piston stroke, but not like using 91 octane.

Piston stroke is fixed. It cannot get longer. See above.

Your test is just us taking your word for it with no real comparison logs or data point to refer to. However, we are not scientist with grants to perform proper testing of the interesting theories we come up with; so I understand that you will not spend your own money just to convince anyone on a forum that you may have discovered that the 3.3T runs better with 87 octane.

This is partly true and why I said it's food for thought. I did originally produce Dragy data when I first did the testing.

My 5.0 engine ran like crap with 87 octane in the summer, however it may run better with it in the winter as your theory suggest due to the cooler air further resisting pre-igniton as the piston compress like with 91 octane under the same conditions. However, i still think that 91 octane will run stronger overall even if the engine runs better with 87 in the winter.

Yeah, I run 91 in summer because I'm pretty certain it's going to produce more power and less ignition retard overall. If you recall, I mentioned in the original post that the ambient temps need to be on the cooler side.

I have an open mind, but not a gullible one that believe whatever theory that someone tell me based off the fact that the person claims the car ran a better time and some thread post links that really do not even clarify the person point. Especially if the theory goes against the engineers who created the engine that states otherwise. If Hyundai states that 87 octane gives(or may) reduced performance in their engines; I lean more towards believing them over some guy on a forum.

Page 7 tells it all for the 3.3T and 5.0 engine as well in regard to using 87 octane per the company that built the motors.

https://owners.genesis.com/genesis/us/mygenesis/manuals/glovebox-manual/2019/g70/2019-G70-Owner's-Manual.pdf

Genesis wouldn't recommend you do a throttle body coolant bypass either but you've done it in this thread in hopes of increasing power through colder air. You even state a possible 10-15hp increase and reference torque in measuring performance. I could pick each aspect of that apart pretty easy. There is a saying about people who live in glass houses shouldn't throw rocks...

Coolant Bypass

 

[carguy75]

I think what you mean is that the timing of the spark induced combustion event just after TDC is important for max efficiency and power. Technically a piston always has to go through a complete stroke or there will be severe damage to the piston, rods etc... Again, pre-ignition is super unlikely in a new engine like the 3.3T... Pre-ignition happens before spark plug ignition due to abnormal engine issues such as glowing hot carbon deposits, sharp edges, really hot plug etc... The chances of pre-ignition due to lower octane fuel in the 3.3T is pretty much zero.


Piston stroke is fixed. It cannot get longer. See above.

This is partly true and why I said it's food for thought. I did originally produce Dragy data when I first did the testing.

Yeah, I run 91 in summer because I'm pretty certain it's going to produce more power and less ignition retard overall. If you recall, I mentioned in the original post that the ambient temps need to be on the cooler side.

Genesis wouldn't recommend you do a throttle body coolant bypass either but you've done it in this thread in hopes of increasing power through colder air. You even state a possible 10-15hp increase and reference torque in measuring performance. I could pick each aspect of that apart pretty easy. There is a saying about people who live in glass houses shouldn't throw rocks...

Coolant Bypass

Well, Hyundai never made any public comment about the coolant in the throttle body reducing horsepower or not, therefore a throttle-body coolant-bypass is not in the owner manual as a topic at all. Fuel octane is specifically addressed in the manual. So piss poor point to use to prove your case.

Furthermore, my hp estimation with a throttle-body coolant bypass is just that; a estimation based on the fact that the intake air charge is about 30F cooler without hot coolant flowing thru the throttle-body. However, in reality the hp gains could be more less. Every engine I researched that had a coolant by pass had different gains; some older engines gained as few as 3hp and some newer engines gained about 10-15hp. I admit that I have no real factual data on the claim because I will never spend money for a dyno session to find out. Butt dyno only.

In regards to piston stroke; I am surprised that you think I am referring to a physical change in piston stroke. By longer stroke I was referring to a more complete stroke without pre-ignition.

However, I maybe confusing how an engine behaves with fuel with a lower octane than desired. I believe an engine will detonate and then somehow the engine looses power due to knocking and detonation. I assumed that it means that the piston stroke is affected somehow, but I can admit that i may be incorrect in that regard. I think knocking and low octane fuels reduces engine power due to how it burns in the engine which negatively affects power delivery when the piston compress the fuel air mixture in an improper way. So it seems that piston strokes does not appear to be reduced or shorten based on low octane use and pre-ignition. I stand corrected if I am incorrect.

I am not an automotive engineer. All I know is that it is bad to use a octane below what the engine requires and that modern engines are more flexible with octane requirements; and that an engine still runs at its best with the octane the manufacturer recommends.

 

[Truck Norris]

Just stumbled across this after reading this thread earlier. All Shell 91 octane gas in Canada is ethanol free.

Shell V-Power NiTRO+ Premium Gasoline