dtru1222
Senior Member
- Joined
- Jul 22, 2012
- Posts
- 240
- Reaction score
- 44
- Ram Year
- 2012
- Engine
- 5.7
This started out as a comment on another members thread which made me realize I have been giving a few points of information from my experience, but not fully explaining them.
There is always a lot of confusion when it comes to octane and performance on the stock tune and the canned DiabloSport tunes.
I think the issue is that there is no one answer that fits all scenarios.
Stock tune;
A lot of people ask if it is worth running 93 octane on the stock tune. You will get people who say yes, you will get people who say no. What it really comes down to is how is your vehicle performing on 87? How much ST and LT knock retard are you getting running 87? Just to clarify, knock retard is not always audible so simply listening for knock will not tell you the true story. Your options are a tuner that can log/monitor KR or one of the $7 bluetooth OBD II set ups.
If you are getting more than 2 ST or ANY LT knock then moving up a grade will benefit you both power and MPG wise. If you go up a grade and you are still seeing those knock numbers then keep going up until it is gone.
If you are running 87 octane and you see 0 ST or LT knock then moving up a grade will be useless and a waste of money, BUT (a big but) over the past 5 years I have been browsing the Ram/Challenger forums, I have yet to see one single person who gets 0 knock on 87 or even 89 octane. I am not saying it is impossible but I have yet to see it.
In my own experience, even running 93 octane on the stock tune I was seeing 9 ST and 1 LT Knock Retard but that is due to the poor quality fuel in my area. The general rule of thumb is that for every 1 degree of ST Knock Retard, you lose 5hp. 9 x 5 = 45hp so you can imagine how big of an impact knock was having on my performance. I recorded several data logs over the span of a few months while I tested out the different gas stations in my area and found that any Chevron station gave me significantly less knock than any others. This may not be true in your area but I encourage you to test the different brands. Typically BP, Shell and Chevron tend to be the best performers and are even recommended by some of the top tuners. In my area BP is not available and Chevron outperforms Shell.
During my second tank of 93 octane I noticed an increase in my MPG. Doing the math shows that the increased price at the pump was negated by the increased MPG I was seeing. This means that I was not paying any extra for the premium fuel over 87 but I was getting more performance. Win/win. This may not be true for everyone else but again I encourage testing it out for yourself.
I just want to make something clear. Running 87 octane WILL NOT hurt your vehicle. Many of the arguments I see in these threads are people saying something like “I have used 87 octane since I bought my vehicle and I have no issues”. There is a big difference between having no issues and running at optimal performance. You can run 87 octane for the life of your vehicle and will probably have no issues if you conduct proper maintenance, but that does not mean that you are using the full potential of your engine.
Canned tunes;
There are many people who buy a tuner, immediately install the 93 octane tune, then call it junk after their performance actually drops. I hate to admit it but I too was one of these people. But there are just as many people who have good first experiences as there are people who have bad ones. As an analyst this is a clear sign that there must be some variable that accounts for the different experiences. The fact that there are so many out there who have good experiences told me that my bad experience was not the norm and warrants some looking into. After 5 years talking to the folks in these forums and testing/analyzing my own data on the 4 Dodge vehicles I have owned I have come to the conclusion that the variable is Knock Retard.
There are various different reasons for Knock, these are some of the things I have found while working on eliminating knock on my vehicles in order of how big of an effect they had on my knock values:
Poor fuel quality/too low of octane
Oil vapors from the PCV system being sucked into the intake
Inconsistency in spark plug gap on originally installed spark plugs
Intake manifold bolts not torqued to spec from the factory (common on Challengers)
Dirty fuel lines
Excessive heat (engine and intake temperatures)
False knock
The reason I list these under the canned tune header is the fact that ALL performance issues I have seen people complain about, and originally had myself, were due to the canned 93 octane tune INCREASING knock. I like many others, filled up with 93 octane tuned for the 93 canned tune then immediately went out and did a 0-60 comparison. I was furious when my results were worse than the stock tune. I went to the DS forums flaming their product (Sorry MikeL) and noticed I was not the only one having these issues. It was there that I realized that something didn’t add up because there were many others who loved the performance increase.
The most common solution/recommendation is to first run the 91 canned tune on 93 octane. For the experienced people who roam the forums (both Ram, Challenger and DS) helping others, this is always the recommended set up when using canned tunes.
This is my step by step personal recommendation for anyone looking to either get the most performance out of their stock tune or use a canned tune.
If you do not have a tuner you can get a Bluetooth OBDII module off of Ebay for $7. They usually come with the software to datalog so you can record your findings.
On your stock tune or canned tune, whatever fuel you have been running, log your ST and LT knock retard. If they register 0 for the whole log then you are fine and there is no need to change anything.
If you see more than 2 ST or ANY LT, then try going up an octane grade and log another run. Note: It is common to see a short spike in ST during shifts. If it spikes then quickly falls in the middle of a shift then there is no issue.
If you are up to 93 octane and you are still seeing knock then I would recommend a catch can. Many people bash them saying they are useless but nearly all tuners for these newer Dodge engines will recommend the same thing and they do it for a reason. It has consistently been shown to reduce Knock.
If you already have a catch can or you do not want to purchase one then my next recommendation would be to replace your spark plugs. I know some will think that’s going a little far but from what I have seen on the forums and for myself on my Challenger is that the gap on the stock plugs are inconsistent and usually much shorter than the owner’s manual recommends. The reason I suggest changing them instead of checking is that they use a crush type washer which once removed, should be replaced. This cleaned up much of my Knock, idle and start up issues and even smoothed out my throttle lag a bit.
I am not sure if this is common on Rams but there have been many people (including myself) who have reported that the stock intake manifold bolts were very loose and once torqued to spec, it helped out their idle and throttle lag issues. For me it also resulted in less Knock, I believe mine were very loose as I had to rotate them several full turns before they were even snug.
If you have more than 10k miles I would recommend using a complete fuel system cleaner. I do this before every oil change and it makes a noticeable difference in power delivery. The most recommended product is the Techron Concentrate 20oz Fuel System cleaner, but I recommend Redline SI-1 as it makes the most noticeable difference to me.
Another option is to reduce the overall heat of the engine. If you have a tuner this can be accomplished by adding a 180 thermostat and dropping your fan settings 20 across the board. This has been one of the most common mods to combat heat simply because it is effective.
If you have tried all the above and you are still getting knock, you may want to check to see if it is false knock that is registering as ST. My suggestion is to purchase the NOS Racing Formula octane booster that will increase octane by 70 points or 7 full octane points. When using this product along with 93 octane fuel you should see nearly 0 knock. If you are still getting knock then there is a good chance that it is false and you should examine your engine bay for anything that may be loose rattling around or hitting the engine.
WARNING: Octane boosters have the potential to foul your spark plugs. I only recommend this exact brand because it was recommended to me and it worked for exactly what I needed it to. I do not recommend using on a regular basis as I only used one can and when I changed my plugs it left an orange coating on them. If you have followed my steps and you are only seeing 1-2 ST and 0 LT knock then there is no use running a booster as even the top custom tuners agree that 1-2 ST is an acceptable amount of knock.
I know this is pretty long and probably not the best formatting but I think it explains what I have learned over the past few years I have been searching and talking to people on these forums. Hope that it helps a few people who may be stuck wondering why they are not getting the performance they expected.
There is always a lot of confusion when it comes to octane and performance on the stock tune and the canned DiabloSport tunes.
I think the issue is that there is no one answer that fits all scenarios.
Stock tune;
A lot of people ask if it is worth running 93 octane on the stock tune. You will get people who say yes, you will get people who say no. What it really comes down to is how is your vehicle performing on 87? How much ST and LT knock retard are you getting running 87? Just to clarify, knock retard is not always audible so simply listening for knock will not tell you the true story. Your options are a tuner that can log/monitor KR or one of the $7 bluetooth OBD II set ups.
If you are getting more than 2 ST or ANY LT knock then moving up a grade will benefit you both power and MPG wise. If you go up a grade and you are still seeing those knock numbers then keep going up until it is gone.
If you are running 87 octane and you see 0 ST or LT knock then moving up a grade will be useless and a waste of money, BUT (a big but) over the past 5 years I have been browsing the Ram/Challenger forums, I have yet to see one single person who gets 0 knock on 87 or even 89 octane. I am not saying it is impossible but I have yet to see it.
In my own experience, even running 93 octane on the stock tune I was seeing 9 ST and 1 LT Knock Retard but that is due to the poor quality fuel in my area. The general rule of thumb is that for every 1 degree of ST Knock Retard, you lose 5hp. 9 x 5 = 45hp so you can imagine how big of an impact knock was having on my performance. I recorded several data logs over the span of a few months while I tested out the different gas stations in my area and found that any Chevron station gave me significantly less knock than any others. This may not be true in your area but I encourage you to test the different brands. Typically BP, Shell and Chevron tend to be the best performers and are even recommended by some of the top tuners. In my area BP is not available and Chevron outperforms Shell.
During my second tank of 93 octane I noticed an increase in my MPG. Doing the math shows that the increased price at the pump was negated by the increased MPG I was seeing. This means that I was not paying any extra for the premium fuel over 87 but I was getting more performance. Win/win. This may not be true for everyone else but again I encourage testing it out for yourself.
I just want to make something clear. Running 87 octane WILL NOT hurt your vehicle. Many of the arguments I see in these threads are people saying something like “I have used 87 octane since I bought my vehicle and I have no issues”. There is a big difference between having no issues and running at optimal performance. You can run 87 octane for the life of your vehicle and will probably have no issues if you conduct proper maintenance, but that does not mean that you are using the full potential of your engine.
Canned tunes;
There are many people who buy a tuner, immediately install the 93 octane tune, then call it junk after their performance actually drops. I hate to admit it but I too was one of these people. But there are just as many people who have good first experiences as there are people who have bad ones. As an analyst this is a clear sign that there must be some variable that accounts for the different experiences. The fact that there are so many out there who have good experiences told me that my bad experience was not the norm and warrants some looking into. After 5 years talking to the folks in these forums and testing/analyzing my own data on the 4 Dodge vehicles I have owned I have come to the conclusion that the variable is Knock Retard.
There are various different reasons for Knock, these are some of the things I have found while working on eliminating knock on my vehicles in order of how big of an effect they had on my knock values:
Poor fuel quality/too low of octane
Oil vapors from the PCV system being sucked into the intake
Inconsistency in spark plug gap on originally installed spark plugs
Intake manifold bolts not torqued to spec from the factory (common on Challengers)
Dirty fuel lines
Excessive heat (engine and intake temperatures)
False knock
The reason I list these under the canned tune header is the fact that ALL performance issues I have seen people complain about, and originally had myself, were due to the canned 93 octane tune INCREASING knock. I like many others, filled up with 93 octane tuned for the 93 canned tune then immediately went out and did a 0-60 comparison. I was furious when my results were worse than the stock tune. I went to the DS forums flaming their product (Sorry MikeL) and noticed I was not the only one having these issues. It was there that I realized that something didn’t add up because there were many others who loved the performance increase.
The most common solution/recommendation is to first run the 91 canned tune on 93 octane. For the experienced people who roam the forums (both Ram, Challenger and DS) helping others, this is always the recommended set up when using canned tunes.
This is my step by step personal recommendation for anyone looking to either get the most performance out of their stock tune or use a canned tune.
If you do not have a tuner you can get a Bluetooth OBDII module off of Ebay for $7. They usually come with the software to datalog so you can record your findings.
On your stock tune or canned tune, whatever fuel you have been running, log your ST and LT knock retard. If they register 0 for the whole log then you are fine and there is no need to change anything.
If you see more than 2 ST or ANY LT, then try going up an octane grade and log another run. Note: It is common to see a short spike in ST during shifts. If it spikes then quickly falls in the middle of a shift then there is no issue.
If you are up to 93 octane and you are still seeing knock then I would recommend a catch can. Many people bash them saying they are useless but nearly all tuners for these newer Dodge engines will recommend the same thing and they do it for a reason. It has consistently been shown to reduce Knock.
If you already have a catch can or you do not want to purchase one then my next recommendation would be to replace your spark plugs. I know some will think that’s going a little far but from what I have seen on the forums and for myself on my Challenger is that the gap on the stock plugs are inconsistent and usually much shorter than the owner’s manual recommends. The reason I suggest changing them instead of checking is that they use a crush type washer which once removed, should be replaced. This cleaned up much of my Knock, idle and start up issues and even smoothed out my throttle lag a bit.
I am not sure if this is common on Rams but there have been many people (including myself) who have reported that the stock intake manifold bolts were very loose and once torqued to spec, it helped out their idle and throttle lag issues. For me it also resulted in less Knock, I believe mine were very loose as I had to rotate them several full turns before they were even snug.
If you have more than 10k miles I would recommend using a complete fuel system cleaner. I do this before every oil change and it makes a noticeable difference in power delivery. The most recommended product is the Techron Concentrate 20oz Fuel System cleaner, but I recommend Redline SI-1 as it makes the most noticeable difference to me.
Another option is to reduce the overall heat of the engine. If you have a tuner this can be accomplished by adding a 180 thermostat and dropping your fan settings 20 across the board. This has been one of the most common mods to combat heat simply because it is effective.
If you have tried all the above and you are still getting knock, you may want to check to see if it is false knock that is registering as ST. My suggestion is to purchase the NOS Racing Formula octane booster that will increase octane by 70 points or 7 full octane points. When using this product along with 93 octane fuel you should see nearly 0 knock. If you are still getting knock then there is a good chance that it is false and you should examine your engine bay for anything that may be loose rattling around or hitting the engine.
WARNING: Octane boosters have the potential to foul your spark plugs. I only recommend this exact brand because it was recommended to me and it worked for exactly what I needed it to. I do not recommend using on a regular basis as I only used one can and when I changed my plugs it left an orange coating on them. If you have followed my steps and you are only seeing 1-2 ST and 0 LT knock then there is no use running a booster as even the top custom tuners agree that 1-2 ST is an acceptable amount of knock.
I know this is pretty long and probably not the best formatting but I think it explains what I have learned over the past few years I have been searching and talking to people on these forums. Hope that it helps a few people who may be stuck wondering why they are not getting the performance they expected.
Last edited:
