chevron or shell gas?
Junior User
Joined: Oct 2004
Posts: 93
Likes: 0
From: Amishland,Pa.
You get your engine use to running on high octane gas then switch down to 87 it WILL starve for the higher octane and PING!!!
03F150,What does this have to do with my post?Did you run high test for years then switch to 87??
"i had 180,000 miles on my 97 F150 when i recently traded it off. It did not ping when i sold it and i never had any kind of repair shop fuel injection cleaning treatment altho once every 15,000 miles or so i used the chevron techrone treatment from walmart (about $6 a pop). Nearly all of those miles were run on chevron so i prefer it. But shell is just as good."
03F150,What does this have to do with my post?Did you run high test for years then switch to 87??
"i had 180,000 miles on my 97 F150 when i recently traded it off. It did not ping when i sold it and i never had any kind of repair shop fuel injection cleaning treatment altho once every 15,000 miles or so i used the chevron techrone treatment from walmart (about $6 a pop). Nearly all of those miles were run on chevron so i prefer it. But shell is just as good."
Tuned
Joined: Oct 2004
Posts: 441
Likes: 6
From: Madison, WI
I think we have a misconception about what exactly "Octane" is here.
Octane is not like Oil, Gas, Transmission Fluid, or any other essential liquid in your vehicle. Octane is added to gasoline to lower the flash point (so it burns hotter, faster, and with less catalyst action).
In reality, it is impossible to "starve" your engine of octane. In relative terms, octane is not an essential component of the combustion process.
The fact that you say that you will experience a "ping" after you switche over to a lower octane fuel may be a result of other things, but NONE are because you are "starving you engine of octane."
Your engine may have ALWAYS detonated (pinged) with this lower grade fuel, however you immediately switched over to a higher octane and the ping went away. (There must have been reason you switched in the first place). The motor is simply running the same way it originally ran on a lower octane fuel.
Second, perhaps your motor is dirty with unburned carbon deposits inside. This would cause the higher flash point (lower octane rating) fuel to simply boil, bubble, and outgas before it ignited. With a higher octane fuel, it would burn hotter and faster, and the computer would detect this ping, and adjust the timing to silence the ping. The timing can only retarded or advanced so far, so maybe this lower grade fuel is just too inflamable for the condition of your motor, for the timing to self adjust.
The old style distributors had weights or vaccuume advances on the distributor to mathematically advance or retard the timing based on engine revolutions. The new motors are all electronic.
There are several other reasons why your motor may knock or ping, but switching to a lower grade fuel after running a high grade fuel with not "induce" a ping in any motor. The ping you hear after the switch has always been there, it has just been rectifeid by your previous choice of fuel.
I hope I wasn;t too confusing.
MK
Octane is not like Oil, Gas, Transmission Fluid, or any other essential liquid in your vehicle. Octane is added to gasoline to lower the flash point (so it burns hotter, faster, and with less catalyst action).
In reality, it is impossible to "starve" your engine of octane. In relative terms, octane is not an essential component of the combustion process.
The fact that you say that you will experience a "ping" after you switche over to a lower octane fuel may be a result of other things, but NONE are because you are "starving you engine of octane."
Your engine may have ALWAYS detonated (pinged) with this lower grade fuel, however you immediately switched over to a higher octane and the ping went away. (There must have been reason you switched in the first place). The motor is simply running the same way it originally ran on a lower octane fuel.
Second, perhaps your motor is dirty with unburned carbon deposits inside. This would cause the higher flash point (lower octane rating) fuel to simply boil, bubble, and outgas before it ignited. With a higher octane fuel, it would burn hotter and faster, and the computer would detect this ping, and adjust the timing to silence the ping. The timing can only retarded or advanced so far, so maybe this lower grade fuel is just too inflamable for the condition of your motor, for the timing to self adjust.
The old style distributors had weights or vaccuume advances on the distributor to mathematically advance or retard the timing based on engine revolutions. The new motors are all electronic.
There are several other reasons why your motor may knock or ping, but switching to a lower grade fuel after running a high grade fuel with not "induce" a ping in any motor. The ping you hear after the switch has always been there, it has just been rectifeid by your previous choice of fuel.
I hope I wasn;t too confusing.
MK
Elder User
Joined: Jul 2004
Posts: 511
Likes: 0
From: South Jersey
Originally Posted by mkoser
I think we have a misconception about what exactly "Octane" is here.
Octane is not like Oil, Gas, Transmission Fluid, or any other essential liquid in your vehicle. Octane is added to gasoline to lower the flash point (so it burns hotter, faster, and with less catalyst action).
In reality, it is impossible to "starve" your engine of octane. In relative terms, octane is not an essential component of the combustion process.
The fact that you say that you will experience a "ping" after you switche over to a lower octane fuel may be a result of other things, but NONE are because you are "starving you engine of octane."
Your engine may have ALWAYS detonated (pinged) with this lower grade fuel, however you immediately switched over to a higher octane and the ping went away. (There must have been reason you switched in the first place). The motor is simply running the same way it originally ran on a lower octane fuel.
Second, perhaps your motor is dirty with unburned carbon deposits inside. This would cause the higher flash point (lower octane rating) fuel to simply boil, bubble, and outgas before it ignited. With a higher octane fuel, it would burn hotter and faster, and the computer would detect this ping, and adjust the timing to silence the ping. The timing can only retarded or advanced so far, so maybe this lower grade fuel is just too inflamable for the condition of your motor, for the timing to self adjust.
The old style distributors had weights or vaccuume advances on the distributor to mathematically advance or retard the timing based on engine revolutions. The new motors are all electronic.
There are several other reasons why your motor may knock or ping, but switching to a lower grade fuel after running a high grade fuel with not "induce" a ping in any motor. The ping you hear after the switch has always been there, it has just been rectifeid by your previous choice of fuel.
I hope I wasn;t too confusing.
MK
Octane is not like Oil, Gas, Transmission Fluid, or any other essential liquid in your vehicle. Octane is added to gasoline to lower the flash point (so it burns hotter, faster, and with less catalyst action).
In reality, it is impossible to "starve" your engine of octane. In relative terms, octane is not an essential component of the combustion process.
The fact that you say that you will experience a "ping" after you switche over to a lower octane fuel may be a result of other things, but NONE are because you are "starving you engine of octane."
Your engine may have ALWAYS detonated (pinged) with this lower grade fuel, however you immediately switched over to a higher octane and the ping went away. (There must have been reason you switched in the first place). The motor is simply running the same way it originally ran on a lower octane fuel.
Second, perhaps your motor is dirty with unburned carbon deposits inside. This would cause the higher flash point (lower octane rating) fuel to simply boil, bubble, and outgas before it ignited. With a higher octane fuel, it would burn hotter and faster, and the computer would detect this ping, and adjust the timing to silence the ping. The timing can only retarded or advanced so far, so maybe this lower grade fuel is just too inflamable for the condition of your motor, for the timing to self adjust.
The old style distributors had weights or vaccuume advances on the distributor to mathematically advance or retard the timing based on engine revolutions. The new motors are all electronic.
There are several other reasons why your motor may knock or ping, but switching to a lower grade fuel after running a high grade fuel with not "induce" a ping in any motor. The ping you hear after the switch has always been there, it has just been rectifeid by your previous choice of fuel.
I hope I wasn;t too confusing.
MK
High octane fuel is tougher to burn than low octane fuel. Low octane fuel is easier to burn than high octane fuel. Octane retards the burning process. Compression creates heat. In high compression engine you need more octane to keep the fuel from igniting until the spark plug fire the air/fuel charge in the combustion chamber. Using fuel without enough octane in engines with high compression will cause pre-ignition or the pinging you hear. Burning fuel with more octane than the manuf recommends just wastes money and will contribute to more carbon build up in an engine. With high octane fuel in a low compression engine you won't get completely clean burn in the combustion chamber.
Burn what the manuf recommends..
Tuned
Joined: Oct 2004
Posts: 441
Likes: 6
From: Madison, WI
Right on DUNK.
I typed that at 12:02 am and completely reveresed my higher and lower flashpoints for some reason.. So if you read that, substitute higer for lower, and lower for higher and you will be all set.
Sorry about that, good catch DUNK.
MK
I typed that at 12:02 am and completely reveresed my higher and lower flashpoints for some reason.. So if you read that, substitute higer for lower, and lower for higher and you will be all set.
Sorry about that, good catch DUNK.
MK
Thread
Thread Starter
Forum
Replies
Last Post
caedes
Pre-Power Stroke Diesel (7.3L IDI & 6.9L)
8
Jun 1, 2015 05:56 AM
armashby
1980 - 1986 Bullnose F100, F150 & Larger F-Series Trucks
16
Jul 31, 2014 06:37 PM
