few questions on octane and additives
03-03-2014, 06:42 AM
#21
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Thread Starter
Join Date: Dec 2013
Location: USA
Posts: 371
I live in a very small town so do a lot of short trips...(my daily drive is like 3 miles one way :/) So part of maintaining, should I go on a 40 minute drive twice a month or something? what do you recommend?
03-03-2014, 08:42 AM
#22
2nd Gear Member
Join Date: Jan 2014
Location: wi
Posts: 163
gas rating
For one how does the car know what you put in it?? So how do you know it makes its power on prem, and not 87. The only way to tell is to check your knock sensor info on the data stream. ALot of these manufactuers hate to say it rec the Higher octane strictly for deals with oil and gas companies. If you run 87 and dont knock the computer aint going to pull timing out, you gonna make more power then on 87 then prem. When people say its tuned for prem. mostly its a timing advance. Most NA engines unless comp really high, or have power combustion chamber issues arn't going to knock on Reg. gas. Would love to see What your Prem. Tuned car does on the dyno with a tank of prem. then a tank of Reg. and would like to see the knock sensor Info. Be interesting to know what they advancing your timing to for your Prem. Tune. Just food for thought. Spent 25 years as a mech. Talked to alot of engineers in that time would be amazed why some choices are made.
03-03-2014, 09:20 AM
#23
4th Gear Member
Join Date: Jul 2011
Location: Michigan
Posts: 1,329
For one how does the car know what you put in it?? So how do you know it makes its power on prem, and not 87. The only way to tell is to check your knock sensor info on the data stream. ALot of these manufactuers hate to say it rec the Higher octane strictly for deals with oil and gas companies.
If you run 87 and dont knock the computer aint going to pull timing out, you gonna make more power then on 87 then prem. When people say its tuned for prem. mostly its a timing advance. Most NA engines unless comp really high,
or have power combustion chamber issues arn't going to knock on Reg. gas. Would love to see What your Prem. Tuned car does on the dyno with a tank of prem. then a tank of Reg. and would like to see the knock sensor Info. Be interesting to know what they advancing your timing to for your Prem. Tune. Just food for thought.
03-03-2014, 09:22 AM
#24
25 years and 25 posts coincidence? You should know the cars now-a-days are smart, the damned computers can do so much crap that most people can't even begin to comprehend. Now I run 93 because I'm tuned to 91. But what all of you are saying, is that I should say %&$^ it and run 87, because its the same crap and wont hurt.... and the 93 will foul my car up?! Funny. Cause I found some fouled sparks... when the car was running 87 not 91+.... You're arguments make no sense. Using the (albeit averaged) method of #gallons filled vs miles driven, in BOTH my cars I got BETTER gas mileage with Shell 93 than with Shell 87. (08 GT and 08 Chev Impala LT). Done driving the same route to work at the same average speed with the same approx traffic.....somewhere i have the notebook logs I was using to track the mileage. In fact the ONLY fuel I had noticed a REAL marked drop in gas mileage? Was using E85.
03-03-2014, 12:29 PM
#25
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Join Date: Jan 2014
Location: wi
Posts: 163
Oh and about 25 posts, yea new to this Forum have been on others for years. Sorry i Dont have time to search the Net and find or post on every Forum out there.Ok DL for 1 I've never said higher pump octane will F your car up. look at your pumps reg.mid.prem. range is what 87 to 93 so whats that 6 points of octane rating?? Most standard vehicles wont get damaged by running pump gas.(E-85 Different discussion). Racing fuels also a Different discussion.
Octane rating as said above is Effects Knock of an engine. You want the Definition of Knock look it up. (look under detonation)
As for cars being smarter. They just have more options they can adjust is all. Still a Combustion engine. Looking for same Air/fuel ratios, timing, etc that we have always looked at. Just you may have more cams, variable timing, variable Fuel injection and so on. (again staying away for FI be it turbo or supercharger for this discussion). IF your only concern is Fuel Economy you have to look at the fuel % versus additive % IMO Different gas companies run different %'s What do you think is going to get better mileage more Fuel in the gal. or more additive %. SO without out knowing the exact make up of each. Different blends do get different MPGs. Agree with you there. But dont think its the octane rating thats doing it.
and for E-85 you need roughly a ratio of 1.6 to 1 versus Gasoline so yea you gonna see MPG drop. (imo i wouldnt waste running E-85 on a NA car unless i got no other choice. Now if its Blown,boosted,Bottle fed E-85 has some nice advantages)
I've been talking HP in my posts. And like i have said the lower number octane fuel you can run without detonation occuring, the more power you going to make. Like you say your tuned for 91. Then your wasting money on 93 or higher IMO. Gas around here is .15$ between fuel levels. So your wasting 1-2 dollars per fill up. And if you put lets say 104 in it according to you it should run even better and get better economy right? Bet it dont unless you make some tuning changes. And as you say about cars being smarter. (then why have you needed to get it Tuned??) The computer has only a operating Window it can make changes in. It needs to be tuned to change the parameters of that Window.
Octane rating as said above is Effects Knock of an engine. You want the Definition of Knock look it up. (look under detonation)
As for cars being smarter. They just have more options they can adjust is all. Still a Combustion engine. Looking for same Air/fuel ratios, timing, etc that we have always looked at. Just you may have more cams, variable timing, variable Fuel injection and so on. (again staying away for FI be it turbo or supercharger for this discussion). IF your only concern is Fuel Economy you have to look at the fuel % versus additive % IMO Different gas companies run different %'s What do you think is going to get better mileage more Fuel in the gal. or more additive %. SO without out knowing the exact make up of each. Different blends do get different MPGs. Agree with you there. But dont think its the octane rating thats doing it.
and for E-85 you need roughly a ratio of 1.6 to 1 versus Gasoline so yea you gonna see MPG drop. (imo i wouldnt waste running E-85 on a NA car unless i got no other choice. Now if its Blown,boosted,Bottle fed E-85 has some nice advantages)
I've been talking HP in my posts. And like i have said the lower number octane fuel you can run without detonation occuring, the more power you going to make. Like you say your tuned for 91. Then your wasting money on 93 or higher IMO. Gas around here is .15$ between fuel levels. So your wasting 1-2 dollars per fill up. And if you put lets say 104 in it according to you it should run even better and get better economy right? Bet it dont unless you make some tuning changes. And as you say about cars being smarter. (then why have you needed to get it Tuned??) The computer has only a operating Window it can make changes in. It needs to be tuned to change the parameters of that Window.
Last edited by bryan67; 03-03-2014 at 12:34 PM.
03-03-2014, 02:41 PM
#26
1st Gear Member
Join Date: Feb 2012
Location: MN
Posts: 117
I've been talking HP in my posts. And like i have said the lower number octane fuel you can run without detonation occuring, the more power you going to make. Like you say your tuned for 91. Then your wasting money on 93 or higher IMO. Gas around here is .15$ between fuel levels. So your wasting 1-2 dollars per fill up. And if you put lets say 104 in it according to you it should run even better and get better economy right? Bet it dont unless you make some tuning changes. And as you say about cars being smarter. (then why have you needed to get it Tuned??) The computer has only a operating Window it can make changes in. It needs to be tuned to change the parameters of that Window.
03-03-2014, 03:04 PM
#27
4th Gear Member
Join Date: Dec 2010
Location: CT
Posts: 1,472
Oh and about 25 posts, yea new to this Forum have been on others for years. Sorry i Dont have time to search the Net and find or post on every Forum out there.Ok DL for 1 I've never said higher pump octane will F your car up. look at your pumps reg.mid.prem. range is what 87 to 93 so whats that 6 points of octane rating?? Most standard vehicles wont get damaged by running pump gas.(E-85 Different discussion). Racing fuels also a Different discussion.
Octane rating as said above is Effects Knock of an engine. You want the Definition of Knock look it up. (look under detonation)
As for cars being smarter. They just have more options they can adjust is all. Still a Combustion engine. Looking for same Air/fuel ratios, timing, etc that we have always looked at. Just you may have more cams, variable timing, variable Fuel injection and so on. (again staying away for FI be it turbo or supercharger for this discussion). IF your only concern is Fuel Economy you have to look at the fuel % versus additive % IMO Different gas companies run different %'s What do you think is going to get better mileage more Fuel in the gal. or more additive %. SO without out knowing the exact make up of each. Different blends do get different MPGs. Agree with you there. But dont think its the octane rating thats doing it.
and for E-85 you need roughly a ratio of 1.6 to 1 versus Gasoline so yea you gonna see MPG drop. (imo i wouldnt waste running E-85 on a NA car unless i got no other choice. Now if its Blown,boosted,Bottle fed E-85 has some nice advantages)
I've been talking HP in my posts. And like i have said the lower number octane fuel you can run without detonation occuring, the more power you going to make. Like you say your tuned for 91. Then your wasting money on 93 or higher IMO. Gas around here is .15$ between fuel levels. So your wasting 1-2 dollars per fill up. And if you put lets say 104 in it according to you it should run even better and get better economy right? Bet it dont unless you make some tuning changes. And as you say about cars being smarter. (then why have you needed to get it Tuned??) The computer has only a operating Window it can make changes in. It needs to be tuned to change the parameters of that Window.
Octane rating as said above is Effects Knock of an engine. You want the Definition of Knock look it up. (look under detonation)
As for cars being smarter. They just have more options they can adjust is all. Still a Combustion engine. Looking for same Air/fuel ratios, timing, etc that we have always looked at. Just you may have more cams, variable timing, variable Fuel injection and so on. (again staying away for FI be it turbo or supercharger for this discussion). IF your only concern is Fuel Economy you have to look at the fuel % versus additive % IMO Different gas companies run different %'s What do you think is going to get better mileage more Fuel in the gal. or more additive %. SO without out knowing the exact make up of each. Different blends do get different MPGs. Agree with you there. But dont think its the octane rating thats doing it.
and for E-85 you need roughly a ratio of 1.6 to 1 versus Gasoline so yea you gonna see MPG drop. (imo i wouldnt waste running E-85 on a NA car unless i got no other choice. Now if its Blown,boosted,Bottle fed E-85 has some nice advantages)
I've been talking HP in my posts. And like i have said the lower number octane fuel you can run without detonation occuring, the more power you going to make. Like you say your tuned for 91. Then your wasting money on 93 or higher IMO. Gas around here is .15$ between fuel levels. So your wasting 1-2 dollars per fill up. And if you put lets say 104 in it according to you it should run even better and get better economy right? Bet it dont unless you make some tuning changes. And as you say about cars being smarter. (then why have you needed to get it Tuned??) The computer has only a operating Window it can make changes in. It needs to be tuned to change the parameters of that Window.
03-03-2014, 03:21 PM
#28
2nd Gear Member
Join Date: Jan 2014
Location: wi
Posts: 163
haha
yea I hear that about the Torco. Just make sure its Unleaded version or can damage cats. I used to fill my tank 50/50 with 104 when i was running my 76 Camaro. would drive it to track mix the fuel and and about 6 Degrees of timing to base. Then readjust after the drive home the next day. Id Love to see what some of these tuners are actually adjusting for a so called 91 tune. Would have to see what there doing to the timing window. Then heres my question tune it for the lower octane will it make more power? Or does changed timing curve and higher octane make the more power? Even with a tune the computers still make adjustments. So once you figure out what octane fuel you need for a tune is more octane gonna make more power?
03-03-2014, 03:37 PM
#30
2nd Gear Member
Join Date: Jan 2014
Location: wi
Posts: 163
true totally agree
yea but most people doing modding arnt changing compression ratios. So doing some bolt on mods do you need to run prem. fuel??? Yea you get into changing comp. ratio or change cylinder pressure you gonna need to increase your octane to prevent detonation. Totally agree. But if you just doing a CAI and maybe exhuast and some kind of tuner work. Is running Prem. going to be needed or make more power then lower octane. OR is running a higher octane going to give you better fuel economy with no other changes.