Octane preference
Thread Starter
Burning Brakes
Joined: Jun 2010
Posts: 774
Likes: 121
From: Jersey Shore
Track Day
Joined: Feb 2014
Posts: 23
Likes: 0
From: Halton region, Canada
Minimum I would dare is 91.......it is the pinging you do not hear that can really hurt you. If you can hear it........get some higher octane in it ASAP......yikes.
After the TPC turbo goes in next month 93 will be my minimum......then maybe methanol injection.......and a supply of Torco handy for spirited driving tests.
After the TPC turbo goes in next month 93 will be my minimum......then maybe methanol injection.......and a supply of Torco handy for spirited driving tests.
Rennlist Member
Joined: Mar 2006
Posts: 6,570
Likes: 89
From: Austin
Race Director
Joined: Sep 2006
Posts: 19,031
Likes: 266
From: Bentonville, AR
Without the benefit of having read the article, I'd hazard a guess because with the proper octane the DME can advance the ignition to the point the maximum mechanical energy is obtained from the chemical energy from burning the gasoline.
With the proper octane the fuel can be ignited and be burning fully and making maximum pressure in the cylinder when the piston/rod/crank is best positioned.
With a bicycle you can get a taste of what this means. Normally one senses when is the best time to apply downward pressure to the pedal to obtain the most benefit from one's pedaling effort.
Try (force yourself) to delay slightly applying this pressure to the pedal. You will immediately detect a drop in performance.
With the proper octane of fuel the engine's more efficient, tractability is at its best -- there is a saying while we buy horsepower we drive torque -- and a tractable vehicle is a more enjoyable to drive.
Fuel economy is as good as it can be and last but not least exhaust gas temperatures are lower than they would be with a lower octane of fuel so engine wear/tear is reduced.
The ethanol is a horrible fuel additive -- its greenness, or lack thereof, is my major reason for disliking its use as a fuel additive (extender/supplement) but it is rather harmless to the car's fuel system and engine and exhaust.
There are many of us say in CA who have used nothing but gasoline with an advertised 10% ethanol (though I understand refineries while they could go to 10% stopped at 7% to 8%) with no harm. My Boxster for example has covered over 281K miles and has all its original fuel system components but the fuel pump. The converters were fine save for one that had a loose brick. It worked most of the time save when the brick fell out of position. The other converter though had no loose brick and worked very well even after all those miles. Plug life has been good and O2 sensor life also has been good.
Thus while I can still *hate* ethanol for the dirty fuel it is (when its entire pollution footprint is taken into account) I can't find any other reason to hate it.
With the proper octane the fuel can be ignited and be burning fully and making maximum pressure in the cylinder when the piston/rod/crank is best positioned.
With a bicycle you can get a taste of what this means. Normally one senses when is the best time to apply downward pressure to the pedal to obtain the most benefit from one's pedaling effort.
Try (force yourself) to delay slightly applying this pressure to the pedal. You will immediately detect a drop in performance.
With the proper octane of fuel the engine's more efficient, tractability is at its best -- there is a saying while we buy horsepower we drive torque -- and a tractable vehicle is a more enjoyable to drive.
Fuel economy is as good as it can be and last but not least exhaust gas temperatures are lower than they would be with a lower octane of fuel so engine wear/tear is reduced.
The ethanol is a horrible fuel additive -- its greenness, or lack thereof, is my major reason for disliking its use as a fuel additive (extender/supplement) but it is rather harmless to the car's fuel system and engine and exhaust.
There are many of us say in CA who have used nothing but gasoline with an advertised 10% ethanol (though I understand refineries while they could go to 10% stopped at 7% to 8%) with no harm. My Boxster for example has covered over 281K miles and has all its original fuel system components but the fuel pump. The converters were fine save for one that had a loose brick. It worked most of the time save when the brick fell out of position. The other converter though had no loose brick and worked very well even after all those miles. Plug life has been good and O2 sensor life also has been good.
Thus while I can still *hate* ethanol for the dirty fuel it is (when its entire pollution footprint is taken into account) I can't find any other reason to hate it.
Nordschleife Master
Joined: Jul 2009
Posts: 5,963
Likes: 113
From: Vancouver, BC
Here I have option of 94 octane with zero ethanol, and I use that all the time. Whenever I go down to WA, and I have to use 91 with ethanol, the car definitely loses power, knocks, and has worse gas mileage.
I simply don't understand the stupid rules, why not make it at least available in limited supply for cars that require it. I cannot even imagine how classic cars would run with such crap gas.
I simply don't understand the stupid rules, why not make it at least available in limited supply for cars that require it. I cannot even imagine how classic cars would run with such crap gas.
Advanced
Joined: Nov 2010
Posts: 67
Likes: 0
From: NW PA
Without the benefit of having read the article, I'd hazard a guess because with the proper octane the DME can advance the ignition to the point the maximum mechanical energy is obtained from the chemical energy from burning the gasoline.
With the proper octane the fuel can be ignited and be burning fully and making maximum pressure in the cylinder when the piston/rod/crank is best positioned.
With a bicycle you can get a taste of what this means. Normally one senses when is the best time to apply downward pressure to the pedal to obtain the most benefit from one's pedaling effort.
Try (force yourself) to delay slightly applying this pressure to the pedal. You will immediately detect a drop in performance.
With the proper octane of fuel the engine's more efficient, tractability is at its best -- there is a saying while we buy horsepower we drive torque -- and a tractable vehicle is a more enjoyable to drive.
Fuel economy is as good as it can be and last but not least exhaust gas temperatures are lower than they would be with a lower octane of fuel so engine wear/tear is reduced.
The ethanol is a horrible fuel additive -- its greenness, or lack thereof, is my major reason for disliking its use as a fuel additive (extender/supplement) but it is rather harmless to the car's fuel system and engine and exhaust.
There are many of us say in CA who have used nothing but gasoline with an advertised 10% ethanol (though I understand refineries while they could go to 10% stopped at 7% to 8%) with no harm. My Boxster for example has covered over 281K miles and has all its original fuel system components but the fuel pump. The converters were fine save for one that had a loose brick. It worked most of the time save when the brick fell out of position. The other converter though had no loose brick and worked very well even after all those miles. Plug life has been good and O2 sensor life also has been good.
Thus while I can still *hate* ethanol for the dirty fuel it is (when its entire pollution footprint is taken into account) I can't find any other reason to hate it.
With the proper octane the fuel can be ignited and be burning fully and making maximum pressure in the cylinder when the piston/rod/crank is best positioned.
With a bicycle you can get a taste of what this means. Normally one senses when is the best time to apply downward pressure to the pedal to obtain the most benefit from one's pedaling effort.
Try (force yourself) to delay slightly applying this pressure to the pedal. You will immediately detect a drop in performance.
With the proper octane of fuel the engine's more efficient, tractability is at its best -- there is a saying while we buy horsepower we drive torque -- and a tractable vehicle is a more enjoyable to drive.
Fuel economy is as good as it can be and last but not least exhaust gas temperatures are lower than they would be with a lower octane of fuel so engine wear/tear is reduced.
The ethanol is a horrible fuel additive -- its greenness, or lack thereof, is my major reason for disliking its use as a fuel additive (extender/supplement) but it is rather harmless to the car's fuel system and engine and exhaust.
There are many of us say in CA who have used nothing but gasoline with an advertised 10% ethanol (though I understand refineries while they could go to 10% stopped at 7% to 8%) with no harm. My Boxster for example has covered over 281K miles and has all its original fuel system components but the fuel pump. The converters were fine save for one that had a loose brick. It worked most of the time save when the brick fell out of position. The other converter though had no loose brick and worked very well even after all those miles. Plug life has been good and O2 sensor life also has been good.
Thus while I can still *hate* ethanol for the dirty fuel it is (when its entire pollution footprint is taken into account) I can't find any other reason to hate it.