If high octane fuel is a waste, then why is TruFuel 93 octane?
What Gas Octane Rating For Mower ?
- Thread starter ChrisD46
- Start date
Originally Posted by Linctex
Originally Posted by propuckstopper
When I go the gas station with a jerry can to buy ethanol free fuel for my OPE, I always put about five or ten bucks in my vehicle first to clear the gas stations's line. My theory is the last guy probably bought E10 for his car, and the line is still full of E10 when I go to fill my jerry can. If i am only buying a gallon or two for the jerry can, a good percentage of my fill could be E10 if I don't clear the line by putting some fuel in my car first.
This has been discussed many times over the years.
The residual fuel is typically about .2 -.3 gallon.
What? You have one line for multiple fuels?
I bet that one for diesel fuel is separate?
Originally Posted by propuckstopper
When I go the gas station with a jerry can to buy ethanol free fuel for my OPE, I always put about five or ten bucks in my vehicle first to clear the gas stations's line. My theory is the last guy probably bought E10 for his car, and the line is still full of E10 when I go to fill my jerry can. If i am only buying a gallon or two for the jerry can, a good percentage of my fill could be E10 if I don't clear the line by putting some fuel in my car first.
This has been discussed many times over the years.
The residual fuel is typically about .2 -.3 gallon.
What? You have one line for multiple fuels?
I bet that one for diesel fuel is separate?
Originally Posted by propuckstopper
Funny you said that. When I go the gas station with a jerry can to buy ethanol free fuel for my OPE, I always put about five or ten bucks in my vehicle first to clear the gas stations's line. My theory is the last guy probably bought E10 for his car, and the line is still full of E10 when I go to fill my jerry can. If i am only buying a gallon or two for the jerry can, a good percentage of my fill could be E10 if I don't clear the line by putting some fuel in my car first.
Super anal, I know. But I'd rather not chance it not knowing how much E10 remains in the pump before I start.
The Wawa station in my area serving up E0 has a dedicated line for it on all of their pumps. The handle is blue to make it obvious. They serve up 89 octane E0 for three cents more than midgrade. I usually put a few gallons in the car while I am at it. All of my 4-cycle OPE runs on E0 now that there is a convenient source. The 2-cycle stuff gets Tru-Fuel premix since I don't use enough of it in a typical season to justify mixing my own.
Funny you said that. When I go the gas station with a jerry can to buy ethanol free fuel for my OPE, I always put about five or ten bucks in my vehicle first to clear the gas stations's line. My theory is the last guy probably bought E10 for his car, and the line is still full of E10 when I go to fill my jerry can. If i am only buying a gallon or two for the jerry can, a good percentage of my fill could be E10 if I don't clear the line by putting some fuel in my car first.
Super anal, I know. But I'd rather not chance it not knowing how much E10 remains in the pump before I start.
The Wawa station in my area serving up E0 has a dedicated line for it on all of their pumps. The handle is blue to make it obvious. They serve up 89 octane E0 for three cents more than midgrade. I usually put a few gallons in the car while I am at it. All of my 4-cycle OPE runs on E0 now that there is a convenient source. The 2-cycle stuff gets Tru-Fuel premix since I don't use enough of it in a typical season to justify mixing my own.
Originally Posted by hatt
Originally Posted by wag123
The Echo 89 octane recommendation is a throwback to a previous era.
The reason that Echo recommended 89 octane in the first place is because of the additional detergents that 89 octane had compared to what cheap 87 octane once had (most 87 octane fuels contained little or NO detergents back in the day, some still don't). The engine does not need the higher octane for resistance to detonation, the compression ratio is too low to require it, Echo just wanted you to use gas that had some added detergent to reduce carbon deposits. Carbon deposits can cause pre-ignition which is FAR more harmful. Modern Top Tier 87 octane gas has an adequate amount of detergent, basically rendering the 89 octane recommendation obsolete (unless you want to use gas that is not Top Tier).
This information came directly from the colorful German gentleman (I forget his name) who was Echo's chief 2-cycle engine design engineer and director of service training during the late 1980's through the early 2000's. His service training classes were legendary.
It's hard to believe the tiny bit of gasoline additives is a big issue when 2 stroke gas has a bunch of oil and associated additives in it.
IDK. I'm not blowing smoke, just passing the information along. The Echo technician training was heavy on engine failure analysis. Gas and oil were a very important part of the training because they were tied-in to most of the engine failures, and we had to learn how to recognize what causes each type of engine failure.
Also, there was a lot of information about oxygenated fuel. Back in the 1990's there wasn't much ethanol being used in gas, but there was quite a bit of MTBE (methyl tert-butyl ether) being used.
Any other technicians who attended the Echo advanced service school that had the colorful German instructor are welcome to chime-in.
Originally Posted by wag123
The Echo 89 octane recommendation is a throwback to a previous era.
The reason that Echo recommended 89 octane in the first place is because of the additional detergents that 89 octane had compared to what cheap 87 octane once had (most 87 octane fuels contained little or NO detergents back in the day, some still don't). The engine does not need the higher octane for resistance to detonation, the compression ratio is too low to require it, Echo just wanted you to use gas that had some added detergent to reduce carbon deposits. Carbon deposits can cause pre-ignition which is FAR more harmful. Modern Top Tier 87 octane gas has an adequate amount of detergent, basically rendering the 89 octane recommendation obsolete (unless you want to use gas that is not Top Tier).
This information came directly from the colorful German gentleman (I forget his name) who was Echo's chief 2-cycle engine design engineer and director of service training during the late 1980's through the early 2000's. His service training classes were legendary.
It's hard to believe the tiny bit of gasoline additives is a big issue when 2 stroke gas has a bunch of oil and associated additives in it.
IDK. I'm not blowing smoke, just passing the information along. The Echo technician training was heavy on engine failure analysis. Gas and oil were a very important part of the training because they were tied-in to most of the engine failures, and we had to learn how to recognize what causes each type of engine failure.
Also, there was a lot of information about oxygenated fuel. Back in the 1990's there wasn't much ethanol being used in gas, but there was quite a bit of MTBE (methyl tert-butyl ether) being used.
Any other technicians who attended the Echo advanced service school that had the colorful German instructor are welcome to chime-in.
87 Octane unless otherwise recommended by the manufacturer.
Had issues with drive belt breaking on my primary rider. Hence I started my old rider that sat for 3 years same old gas and battery hadn't been charged. Needing to jump it but the battery took charge and mower ran fine. I was using regular 87 octane at the pump no stabilizer in it. It is an old Husqvarna with an 12 HP Briggs. No idea how old or hours as no meter but it is definitely well broken in probably on latter end of it's life.
Local E10-87 for lots of work and multiple tankfuls in short amounts of time, leaving the tank empty whenever possible at the end of jobs.
Non-ethanol in whatever octane rating that is easiest to obtain if the mower sits for more than a week between use.
Non-ethanol in whatever octane rating that is easiest to obtain if the mower sits for more than a week between use.
I run Trufuel in mine. 92 octane, 0% ethenol and stabilizer already in it. $6 for a quart at home Depot. 1 bottle fills my super recycler. My yard isn't crazy big so I don't have to fill up too often. Maybe every 2 or 3 cuts.
4WD
$50 site donor 2024
Push mower on down I'm using E0 x 92 … but my Stihl gets small can gas since it's seldom used.
The 19HP B&S and 389cc gens run good on regular Exxon from the corner … using some stabil.
I also started to use that E0 in my shallow water skiff along with Techron MPM mainly since I'm using it less and less … but really look forward to a hassle free fishing trip once in a while.
The 19HP B&S and 389cc gens run good on regular Exxon from the corner … using some stabil.
I also started to use that E0 in my shallow water skiff along with Techron MPM mainly since I'm using it less and less … but really look forward to a hassle free fishing trip once in a while.
Premium gas. Much better starting compared to regular, and perhaps some unseen benefits along with it.
Originally Posted by dinofish
Premium gas. Much better starting compared to regular, and perhaps some unseen benefits along with it.
If you are experiencing better starting it is due to some aspect of the fuel other than the octane rating.
It is amazing the myths surrounding octane rating of gasoline, both what it is and what it is not.
Premium gas. Much better starting compared to regular, and perhaps some unseen benefits along with it.
If you are experiencing better starting it is due to some aspect of the fuel other than the octane rating.
It is amazing the myths surrounding octane rating of gasoline, both what it is and what it is not.
Last edited:
Originally Posted by kschachn
Originally Posted by dinofish
Premium gas. Much better starting compared to regular, and perhaps some unseen benefits along with it.
If you are experiencing better starting it is due to some aspect of the fuel other than the octane rating.
It is amazing the myths surrounding octane rating of gasoline, both what it is and what it is not.
Well, it is not a myth, it is my direct observation. I noticed that regular is only good on the day of filling, and after that, it loses its effectiveness in an increasing manner. I first tried to retain regular's freshness with 'sta-bil', but eventually tried premium and found it to be far superior. I can keep premium in the two gallon can for over two months during winter and still have it be close to being as fresh as the day of filling.
Originally Posted by dinofish
Premium gas. Much better starting compared to regular, and perhaps some unseen benefits along with it.
If you are experiencing better starting it is due to some aspect of the fuel other than the octane rating.
It is amazing the myths surrounding octane rating of gasoline, both what it is and what it is not.
Well, it is not a myth, it is my direct observation. I noticed that regular is only good on the day of filling, and after that, it loses its effectiveness in an increasing manner. I first tried to retain regular's freshness with 'sta-bil', but eventually tried premium and found it to be far superior. I can keep premium in the two gallon can for over two months during winter and still have it be close to being as fresh as the day of filling.
Originally Posted by dinofish
Well, it is not a myth, it is my direct observation. I noticed that regular is only good on the day of filling, and after that, it loses its effectiveness. I first tried to retain freshness with 'sta-bil', but eventually tried premium and found it to be far superior.
Which is fine, but it is not due to the octane rating. There are multiple ways to obtain a specific measured octane rating and one of those aspects is contributing to the effect you're seeing. But it is not in and of itself due to the octane number. Octane rating is solely related to the resistance to pre-ignition.
Well, it is not a myth, it is my direct observation. I noticed that regular is only good on the day of filling, and after that, it loses its effectiveness. I first tried to retain freshness with 'sta-bil', but eventually tried premium and found it to be far superior.
Which is fine, but it is not due to the octane rating. There are multiple ways to obtain a specific measured octane rating and one of those aspects is contributing to the effect you're seeing. But it is not in and of itself due to the octane number. Octane rating is solely related to the resistance to pre-ignition.
Originally Posted by kschachn
Originally Posted by dinofish
Well, it is not a myth, it is my direct observation. I noticed that regular is only good on the day of filling, and after that, it loses its effectiveness. I first tried to retain freshness with 'sta-bil', but eventually tried premium and found it to be far superior.
Which is fine, but it is not due to the octane rating. There are multiple ways to obtain a specific measured octane rating and one of these aspects is contributing to the effect you're seeing. But it is not in and of itself due to the octane number. Octane rating is solely related to the resistance to pre-ignition.
+1
The octane rating has nothing to do with volatility. Gasoline's loss of volatility over time is what causes starting problems. 87 octane gas does not lose it's volatility any faster than higher octane gas. If your engine is hard to start (or won't start) with fuel that is newer than 60 days old, regardless of the octane rating, you have another problem.
I reiterate, the low compression ratio of small air cooled engines does not require a higher octane rating than 87. If a small air cooled engine had a high enough compression ratio to require higher octane fuel, you wouldn't be able to pull start it.
Regardless, if it makes you feel better using higher octane fuel, go ahead and use it, it won't hurt anything.
Originally Posted by dinofish
Well, it is not a myth, it is my direct observation. I noticed that regular is only good on the day of filling, and after that, it loses its effectiveness. I first tried to retain freshness with 'sta-bil', but eventually tried premium and found it to be far superior.
Which is fine, but it is not due to the octane rating. There are multiple ways to obtain a specific measured octane rating and one of these aspects is contributing to the effect you're seeing. But it is not in and of itself due to the octane number. Octane rating is solely related to the resistance to pre-ignition.
+1
The octane rating has nothing to do with volatility. Gasoline's loss of volatility over time is what causes starting problems. 87 octane gas does not lose it's volatility any faster than higher octane gas. If your engine is hard to start (or won't start) with fuel that is newer than 60 days old, regardless of the octane rating, you have another problem.
I reiterate, the low compression ratio of small air cooled engines does not require a higher octane rating than 87. If a small air cooled engine had a high enough compression ratio to require higher octane fuel, you wouldn't be able to pull start it.
Regardless, if it makes you feel better using higher octane fuel, go ahead and use it, it won't hurt anything.
Quote
I reiterate, the low compression ratio of small air cooled engines does not require a higher octane rating than 87. If a small air cooled engine had a high enough compression ratio to require higher octane fuel, you wouldn't be able to pull start it.
Regardless, if it makes you feel better using higher octane fuel, go ahead and use it, it won't hurt anything.
This just isn't true. Compression ratio and octane are not the only attributes that determine the potential for preignition. Engine/combustion chamber design (and resulting combustion stability), ignition and valve timing, air/fuel ratio, altitude, temperature and other variables come into play. Just because an engine has a lower compression ratio does not make it invulnerable to preignition.
I reiterate, the low compression ratio of small air cooled engines does not require a higher octane rating than 87. If a small air cooled engine had a high enough compression ratio to require higher octane fuel, you wouldn't be able to pull start it.
Regardless, if it makes you feel better using higher octane fuel, go ahead and use it, it won't hurt anything.
This just isn't true. Compression ratio and octane are not the only attributes that determine the potential for preignition. Engine/combustion chamber design (and resulting combustion stability), ignition and valve timing, air/fuel ratio, altitude, temperature and other variables come into play. Just because an engine has a lower compression ratio does not make it invulnerable to preignition.
Originally Posted by 92saturnsl2
This just isn't true. Compression ratio and octane are not the only attributes that determine the potential for preignition. Engine/combustion chamber design (and resulting combustion stability), ignition and valve timing, air/fuel ratio, altitude, temperature and other variables come into play. Just because an engine has a lower compression ratio does not make it invulnerable to preignition.
And all of which should be taken into account by the engine designer and reflected in the owner's manual requirement for octane rating.
This just isn't true. Compression ratio and octane are not the only attributes that determine the potential for preignition. Engine/combustion chamber design (and resulting combustion stability), ignition and valve timing, air/fuel ratio, altitude, temperature and other variables come into play. Just because an engine has a lower compression ratio does not make it invulnerable to preignition.
And all of which should be taken into account by the engine designer and reflected in the owner's manual requirement for octane rating.
Originally Posted by kschachn
And all of which should be taken into account by the engine designer and reflected in the owner's manual requirement for octane rating.
Precisely. Use what's in the manual.
And all of which should be taken into account by the engine designer and reflected in the owner's manual requirement for octane rating.
Precisely. Use what's in the manual.
Originally Posted by wag123
Originally Posted by kschachn
Originally Posted by dinofish
Well, it is not a myth, it is my direct observation. I noticed that regular is only good on the day of filling, and after that, it loses its effectiveness. I first tried to retain freshness with 'sta-bil', but eventually tried premium and found it to be far superior.
Which is fine, but it is not due to the octane rating. There are multiple ways to obtain a specific measured octane rating and one of these aspects is contributing to the effect you're seeing. But it is not in and of itself due to the octane number. Octane rating is solely related to the resistance to pre-ignition.
+1
The octane rating has nothing to do with volatility. Gasoline's loss of volatility over time is what causes starting problems. 87 octane gas does not lose it's volatility any faster than higher octane gas. If your engine is hard to start (or won't start) with fuel that is newer than 60 days old, regardless of the octane rating, you have another problem.
I reiterate, the low compression ratio of small air cooled engines does not require a higher octane rating than 87. If a small air cooled engine had a high enough compression ratio to require higher octane fuel, you wouldn't be able to pull start it.
Regardless, if it makes you feel better using higher octane fuel, go ahead and use it, it won't hurt anything.
If it makes you 'feel' that it is all my 'feelings', then go right ahead. You are more than welcome to your 'opinion' vs my direct observation. If it is something else giving better starting with high octane, then address it.
But you can prove it to yourself. Buy two cans and try it with two different fuel types on a small engine after having them both sit for a month. Then you can tell me how you 'feel' about the results. Remember that you have to test it in a small engine. Like a 4-cycle leaf blower, or trimmer, etc. The effects are more immediate and noticeable in smaller the engine.
Originally Posted by kschachn
Originally Posted by dinofish
Well, it is not a myth, it is my direct observation. I noticed that regular is only good on the day of filling, and after that, it loses its effectiveness. I first tried to retain freshness with 'sta-bil', but eventually tried premium and found it to be far superior.
Which is fine, but it is not due to the octane rating. There are multiple ways to obtain a specific measured octane rating and one of these aspects is contributing to the effect you're seeing. But it is not in and of itself due to the octane number. Octane rating is solely related to the resistance to pre-ignition.
+1
The octane rating has nothing to do with volatility. Gasoline's loss of volatility over time is what causes starting problems. 87 octane gas does not lose it's volatility any faster than higher octane gas. If your engine is hard to start (or won't start) with fuel that is newer than 60 days old, regardless of the octane rating, you have another problem.
I reiterate, the low compression ratio of small air cooled engines does not require a higher octane rating than 87. If a small air cooled engine had a high enough compression ratio to require higher octane fuel, you wouldn't be able to pull start it.
Regardless, if it makes you feel better using higher octane fuel, go ahead and use it, it won't hurt anything.
If it makes you 'feel' that it is all my 'feelings', then go right ahead. You are more than welcome to your 'opinion' vs my direct observation. If it is something else giving better starting with high octane, then address it.
But you can prove it to yourself. Buy two cans and try it with two different fuel types on a small engine after having them both sit for a month. Then you can tell me how you 'feel' about the results. Remember that you have to test it in a small engine. Like a 4-cycle leaf blower, or trimmer, etc. The effects are more immediate and noticeable in smaller the engine.
Originally Posted by dinofish
If it makes you 'feel' that it is all my 'feelings', then go right ahead. You are more than welcome to your 'opinion' vs my direct observation. If it is something else giving better starting with high octane, then address it.
But you can prove it to yourself. Buy two cans and try it with two different fuel types on a small engine after having them both sit for a month. Then you can tell me how you 'feel' about the results. Remember that you have to test it in a small engine. Like a 4-cycle leaf blower, or trimmer, etc. The effects are more immediate and noticeable in smaller the engine.
Again, you don't understand what you're saying. There are multiple of ways a blender or refinery can create an apparent octane rating for a fuel and it is these differences in composition you are observing. It is not the octane number itself.
If it makes you 'feel' that it is all my 'feelings', then go right ahead. You are more than welcome to your 'opinion' vs my direct observation. If it is something else giving better starting with high octane, then address it.
But you can prove it to yourself. Buy two cans and try it with two different fuel types on a small engine after having them both sit for a month. Then you can tell me how you 'feel' about the results. Remember that you have to test it in a small engine. Like a 4-cycle leaf blower, or trimmer, etc. The effects are more immediate and noticeable in smaller the engine.
Again, you don't understand what you're saying. There are multiple of ways a blender or refinery can create an apparent octane rating for a fuel and it is these differences in composition you are observing. It is not the octane number itself.
