What would be symptoms of less than 87 octane gas?
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I removed the ethanol from 87 which turned it into 84. It knocked during normal acceleration.
An engine in poor shape may require a higher than normal octane to run without knock. An old engine knocking is no proof that the gas is substandard. If the gasoline knocks in a brand new car then you have something.
An engine in poor shape may require a higher than normal octane to run without knock. An old engine knocking is no proof that the gas is substandard. If the gasoline knocks in a brand new car then you have something.
WOW! You are wasting some money. What is your car doing to make you think it is less than 87?? You should be able to tell us what it feels like in your cars. I'm curious. Not trying to be rude either.
Originally Posted By: severach
I removed the ethanol from 87 which turned it into 84. It knocked during normal acceleration.
An engine in poor shape may require a higher than normal octane to run without knock. An old engine knocking is no proof that the gas is substandard. If the gasoline knocks in a brand new car then you have something.
How did you do that?? Are you a cook...lol
I removed the ethanol from 87 which turned it into 84. It knocked during normal acceleration.
An engine in poor shape may require a higher than normal octane to run without knock. An old engine knocking is no proof that the gas is substandard. If the gasoline knocks in a brand new car then you have something.
How did you do that?? Are you a cook...lol
Originally Posted By: chubbs1
WOW! You are wasting some money. What is your car doing to make you think it is less than 87?? You should be able to tell us what it feels like in your cars. I'm curious. Not trying to be rude either.
I had to laugh just now. How much money do you think I've wasted over the course of a month?
WOW! You are wasting some money. What is your car doing to make you think it is less than 87?? You should be able to tell us what it feels like in your cars. I'm curious. Not trying to be rude either.
I had to laugh just now. How much money do you think I've wasted over the course of a month?
Is it for all of those cars or just one? I would imagine it is a lot of cash if it is all of them.
1 car (Mazda 3), 1 gallon per fill (out of 12), 4 fills per month. I won't do the other cars because I don't drive them.
The gallon of 93 should boost octane by 1/2 a point which would be enough to overcome any gas that's up to 1/2 octane short of the 87 its supposed to be.
I noticed the most difference in the low end (under 2.5k RPM) but I'm really, really trying hard to see if it's just in my head or not. I also do the 4 oz per 10 gallon MMO thing from time to time.
The gallon of 93 should boost octane by 1/2 a point which would be enough to overcome any gas that's up to 1/2 octane short of the 87 its supposed to be.
I noticed the most difference in the low end (under 2.5k RPM) but I'm really, really trying hard to see if it's just in my head or not. I also do the 4 oz per 10 gallon MMO thing from time to time.
Originally Posted By: chubbs1
Originally Posted By: severach
I removed the ethanol from 87 which turned it into 84. It knocked during normal acceleration.
An engine in poor shape may require a higher than normal octane to run without knock. An old engine knocking is no proof that the gas is substandard. If the gasoline knocks in a brand new car then you have something.
How did you do that?? Are you a cook...lol
Phase separation probably. Mixing it with water and letting it sit will result in gas on top and ethanol on bottom attached to the water. Take the gas out without the water and you have phase separated gasoline.
Originally Posted By: severach
I removed the ethanol from 87 which turned it into 84. It knocked during normal acceleration.
An engine in poor shape may require a higher than normal octane to run without knock. An old engine knocking is no proof that the gas is substandard. If the gasoline knocks in a brand new car then you have something.
How did you do that?? Are you a cook...lol
Phase separation probably. Mixing it with water and letting it sit will result in gas on top and ethanol on bottom attached to the water. Take the gas out without the water and you have phase separated gasoline.
ONE octane point is not that big of a deal, but that was based on what you purported. If you have spark knock/pinging your car will hate you and never accelerate. Instead of accelerating, kicking down a gear and moving, it will knock and sputter like a big POS.
We had a Nissan Quest with the VG and a soft code for the knock sensor in full-spin, I bloody hated it when the knock would act up.
We had a Nissan Quest with the VG and a soft code for the knock sensor in full-spin, I bloody hated it when the knock would act up.
Ive noted rough running, spongy throttle, sag, backfiring like a bad plug/ out of tune but I think a more advanced ECU will pull timing and then try to advance constantly which can cause an engine roll of high periodicity. Around here you are lucky if you get reported octane and decent fuel, its usually barely adequate to get around on, never mind get any performance or approach stated horsepower and torque. When this happens over more than 2 tanks I do sometime add 1 or 2 gal of 93 to a tank and performance improves. I ve noted real euro syn (like motul 8100 econergy) make fuel quality transparent - cleaner ring stack I would assume.
Originally Posted By: Vikas
And what if you accidentally grab some water?
better pray it's not a lot of water! that's why I don't do the phase separation thing, at least not for cars. for other equipment like lawn equipment, i can see why you might want to do it
And what if you accidentally grab some water?
better pray it's not a lot of water! that's why I don't do the phase separation thing, at least not for cars. for other equipment like lawn equipment, i can see why you might want to do it
Originally Posted By: ARCOgraphite
Ive noted rough running, spongy throttle, sag, backfiring like a bad plug/ out of tune but I think a more advanced ECU will pull timing and then try to advance constantly which can cause an engine roll of high periodicity. Around here you are lucky if you get reported octane and decent fuel, its usually barely adequate to get around on, never mind get any performance or approach stated horsepower and torque. When this happens over more than 2 tanks I do sometime add 1 or 2 gal of 93 to a tank and performance improves. I ve noted real euro syn (like motul 8100 econergy) make fuel quality transparent - cleaner ring stack I would assume.
ok so it isn't just me!
Ive noted rough running, spongy throttle, sag, backfiring like a bad plug/ out of tune but I think a more advanced ECU will pull timing and then try to advance constantly which can cause an engine roll of high periodicity. Around here you are lucky if you get reported octane and decent fuel, its usually barely adequate to get around on, never mind get any performance or approach stated horsepower and torque. When this happens over more than 2 tanks I do sometime add 1 or 2 gal of 93 to a tank and performance improves. I ve noted real euro syn (like motul 8100 econergy) make fuel quality transparent - cleaner ring stack I would assume.
ok so it isn't just me!
Its probably not the fuel. An electronic malfunction is more likely.
But, if you do have fuel in the tank that is not high enough octane the only thing that will happen is you will lose some power under harder accelleration. You may hear the engine pinging briefly when getting on the throttle hard. Then the engine computer will reduce ignition timing to make the ping stop, in effect lowering the power output per throttle position. You may be able to actually feel the computer doing this under wide open throttle accelleration. Instead of a steay build up of accelleration you may feel the power momentarily decline as if you let up on the accellerator a little. This sensation would be very slight.
Pinging and the lost power sensation are the only indications you would have if you had too low octane for your car.
...but I'd say you have an electronic malfunction with your car based on what you've said.
But, if you do have fuel in the tank that is not high enough octane the only thing that will happen is you will lose some power under harder accelleration. You may hear the engine pinging briefly when getting on the throttle hard. Then the engine computer will reduce ignition timing to make the ping stop, in effect lowering the power output per throttle position. You may be able to actually feel the computer doing this under wide open throttle accelleration. Instead of a steay build up of accelleration you may feel the power momentarily decline as if you let up on the accellerator a little. This sensation would be very slight.
Pinging and the lost power sensation are the only indications you would have if you had too low octane for your car.
...but I'd say you have an electronic malfunction with your car based on what you've said.
Quote:
If I was putting in 86 octane in my car, what are some things it would do?
Run the same as always.
Your knock sensors and electronic control system are continually adjusting the ignition timing. The higher or lower octane may make a very slight difference in power and fuel consumption, but you probably could not measure the difference with the usual speed shop instrumentation.
Any modern (post '86) car that pings either has carbon build up that glows red hot and ignites the gas before the spark fires, or has a defective component, or is made to harmlessly ping slightly.
If I was putting in 86 octane in my car, what are some things it would do?
Run the same as always.
Your knock sensors and electronic control system are continually adjusting the ignition timing. The higher or lower octane may make a very slight difference in power and fuel consumption, but you probably could not measure the difference with the usual speed shop instrumentation.
Any modern (post '86) car that pings either has carbon build up that glows red hot and ignites the gas before the spark fires, or has a defective component, or is made to harmlessly ping slightly.
Originally Posted By: sangyup81
I've been adding plus and premium to my regular gas because I suspect the 87 octane gas may be a bit off from true 87 octane. If I was putting in 86 octane in my car, what are some things it would do?
sangyup81,
Off the top of my head your engine will run rough and stumble a little when you hit the gas pedal because your computer can only adjust the timing just so much. If you get into this situation you might consider topping off your tank right away using 89 octane and it should mix while driving and bring he spes up to a proper level.
Durango
I've been adding plus and premium to my regular gas because I suspect the 87 octane gas may be a bit off from true 87 octane. If I was putting in 86 octane in my car, what are some things it would do?
sangyup81,
Off the top of my head your engine will run rough and stumble a little when you hit the gas pedal because your computer can only adjust the timing just so much. If you get into this situation you might consider topping off your tank right away using 89 octane and it should mix while driving and bring he spes up to a proper level.
Durango
Originally Posted By: mcrn
Is your Mazda DI? Maybe you have some deposits? Just a thought?
If that's the case then I'd put a large bottle of Techron in the tank and take it for a long freeway drive and run it down. Then one more in the other direction and see what happens.
Don't do what I did earlier and wind up spending 5K for a valve job!!! Again I'm back to using Techron. No more Gumout/Regain for me.
Durango
Is your Mazda DI? Maybe you have some deposits? Just a thought?
If that's the case then I'd put a large bottle of Techron in the tank and take it for a long freeway drive and run it down. Then one more in the other direction and see what happens.
Don't do what I did earlier and wind up spending 5K for a valve job!!! Again I'm back to using Techron. No more Gumout/Regain for me.
Durango
Nothing but air and reversion kissing those intake heads. No DI for me.
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