Does running 89octane on a 1.8t cause any harm?
Some have told me that the timing automatically adjusts to prevent knocking.
Some have told me that the timing automatically adjusts to prevent knocking.
Fuel Grade
kaydub
1 - 18 of 18 Posts
Re: Fuel Grade (kaydub)
We have knock sensors to adjust timing, but running 89 will give you a noticable decrease in power and worse gas mileage. Also, VW states clearly that it requires a minimum of 91, listen to them.
Saving yourself 10 cents a gallon is just not worth it.
Also, this topic has been discussed before, if you want to know more, try searching for it. I'm sure someone previously would have given a much better explanation.
| Quote, originally posted by kaydub » |
| Does running 89octane on a 1.8t cause any harm? Some have told me that the timing automatically adjusts to prevent knocking. |
We have knock sensors to adjust timing, but running 89 will give you a noticable decrease in power and worse gas mileage. Also, VW states clearly that it requires a minimum of 91, listen to them.
Saving yourself 10 cents a gallon is just not worth it.
Also, this topic has been discussed before, if you want to know more, try searching for it. I'm sure someone previously would have given a much better explanation.
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7,767 Posts
Re: Fuel Grade (kaydub)
This question gets asked so often that I have a text file with my stock response in it:
You should always use 91+ octane in your car. Yes, the car will adapt to lower octane gas, but it is still bad for the car and here's why:
When lower octane gas is used, knocking (pre-ignition of the gas) occurs. This knocking is detected by the knock sensor, and the ECU retards timing, lowering the compression of the engine & thereby preventing knocking. However, notice what order all this happens in--knocking must occur for timing to be retarded. And the ECU will keep trying to advance the timing again, resulting in a knock-retard-advance-knock cycle. This is very bad for your engine.
Spend the extra 10 cents/gallon on 91 octane or spend thousands down the road on engine repair.
This question gets asked so often that I have a text file with my stock response in it:
You should always use 91+ octane in your car. Yes, the car will adapt to lower octane gas, but it is still bad for the car and here's why:
When lower octane gas is used, knocking (pre-ignition of the gas) occurs. This knocking is detected by the knock sensor, and the ECU retards timing, lowering the compression of the engine & thereby preventing knocking. However, notice what order all this happens in--knocking must occur for timing to be retarded. And the ECU will keep trying to advance the timing again, resulting in a knock-retard-advance-knock cycle. This is very bad for your engine.
Spend the extra 10 cents/gallon on 91 octane or spend thousands down the road on engine repair.
Re: Fuel Grade (AVANT)
If running 89 will show a decrease in power, will running 100 octane show an increase? Will higher than recommended octane fuels hurt a stock 1.8t?
Also, are octane boosters a scam or do they have any performance, cleaning properties?
Anyone run either 100 pump or 93 plus additive?
Thanks in advance.
If running 89 will show a decrease in power, will running 100 octane show an increase? Will higher than recommended octane fuels hurt a stock 1.8t?
Also, are octane boosters a scam or do they have any performance, cleaning properties?
Anyone run either 100 pump or 93 plus additive?
Thanks in advance.
Re: Fuel Grade (isawoj)
The stock ECU will only advance timing to what it is designed to. So while having 100 octane will allow the engine to run more advanced timing, it won't show any benefits until you have programming to take advantage of this. With REVO, you can advance timing with the SPS3 device, or you can have a "race" program from APR or GIAC which will also benefit from the higher octane gas. Even on the stock turbo, people have been able to see 10+ whp gains.
Simple answer: Octane boosters don't work. Once again, use some searches to find your answer if you want something more technical.
The stock ECU will only advance timing to what it is designed to. So while having 100 octane will allow the engine to run more advanced timing, it won't show any benefits until you have programming to take advantage of this. With REVO, you can advance timing with the SPS3 device, or you can have a "race" program from APR or GIAC which will also benefit from the higher octane gas. Even on the stock turbo, people have been able to see 10+ whp gains.
Simple answer: Octane boosters don't work. Once again, use some searches to find your answer if you want something more technical.
Re: Fuel Grade (isawoj)
higher octane will only give you more power if your car is pulling timing. for example, an APR91 octane car pulls about 7-8, but with 100 octane, won't pull timing at all.. so, you get a little more "freed" up.. but its relatively trivial.
93 + additive = waste of money.. you won't even hit 94 octane w/additives.. (2-3 points = .2-.3 octane)
| Quote, originally posted by isawoj » |
| If running 89 will show a decrease in power, will running 100 octane show an increase? Will higher than recommended octane fuels hurt a stock 1.8t? Also, are octane boosters a scam or do they have any performance, cleaning properties? Anyone run either 100 pump or 93 plus additive? Thanks in advance. |
higher octane will only give you more power if your car is pulling timing. for example, an APR91 octane car pulls about 7-8, but with 100 octane, won't pull timing at all.. so, you get a little more "freed" up.. but its relatively trivial.
93 + additive = waste of money.. you won't even hit 94 octane w/additives.. (2-3 points = .2-.3 octane)
Re: Fuel Grade (isawoj)
The day before I got chipped I filled up with 93, and it felt dog slow compared to stock on 91. This was in warm weather, probably high 70s - mid 80s. It still felt slow about 50 miles later, although that isn't very far for adaptation to take place.
91 is specified for stock use country-wide. That includes worst case places like California, Florida and Texas. I figure that in cooler climates timing rarely (if ever) gets pulled on 91 gas, and that in northern winters 91 octane probably is overkill. Don't forget that APR manage to put more boost into an engine whilst running 91 gas in California - there is obviously some headroom available that APRs 91 program can exploit.
I'd love to see some real timing log analysis done on this engine in various climates so that we could give a more definitive answer.
The day before I got chipped I filled up with 93, and it felt dog slow compared to stock on 91. This was in warm weather, probably high 70s - mid 80s. It still felt slow about 50 miles later, although that isn't very far for adaptation to take place.
91 is specified for stock use country-wide. That includes worst case places like California, Florida and Texas. I figure that in cooler climates timing rarely (if ever) gets pulled on 91 gas, and that in northern winters 91 octane probably is overkill. Don't forget that APR manage to put more boost into an engine whilst running 91 gas in California - there is obviously some headroom available that APRs 91 program can exploit.
I'd love to see some real timing log analysis done on this engine in various climates so that we could give a more definitive answer.
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3,197 Posts
Re: Fuel Grade (genixia)
honeslty whats really saved by cheaping out on gas?
$2.25 p/gallon * 15 gallons =$33.75 (89 octane)
$2.40 p/gallon * 15 gallons =$36.00 (91 octane)
imaginary gas prices used for analogy purposes
are you really that hard up for $2.25? i'd rather get a lil more timing out of the money i invested in my chip. if VW states use 91 then i'll stick with that, let alone if i was chiped. If your relying on the knock sensors your losing hp/trq no if and's or butts.
honeslty whats really saved by cheaping out on gas?
$2.25 p/gallon * 15 gallons =$33.75 (89 octane)
$2.40 p/gallon * 15 gallons =$36.00 (91 octane)
imaginary gas prices used for analogy purposes
are you really that hard up for $2.25? i'd rather get a lil more timing out of the money i invested in my chip. if VW states use 91 then i'll stick with that, let alone if i was chiped. If your relying on the knock sensors your losing hp/trq no if and's or butts.
Re: Fuel Grade (RABIDRABBIT1983)
Err... money? If you're filling up once a week that $2.25 is worth over $100 a year.
'Smart' answers aside, I fill up with 93 for my APR93. I filled up with 91 when stock. I don't see anywhere that I stated or suggested otherwise.
How do you know that you are getting "a lil more timing out of the money i invested in my chip" ? Have you measured your timing? A car that _never_ pulls timing is one that is likely to be using gas that is too high in octane, and is likely to be suffering from incomplete combustion, overworking the catalytic converter and wasting money.
My argument was that we have _never_ seen a comprehensive study done on octane ratings in these engines. People fall into one of 3 camps - "I'll use the 'best' gas I can", "I'll use the recommended gas only", or (not really here on the 'tex) "I'll use the cheapest gas I can".
You are obviously in the second camp, and quite prepared to spend the rest of your days believing generic recommendations as gospel truth. Fine. It doesn't automatically make your choice of gas right though. I'd like to see some real analysis before I believe that the same octane is required in Alaska and Texas.
| Quote, originally posted by RABIDRABBIT1983 » |
| honeslty whats really saved by cheaping out on gas? |
Err... money? If you're filling up once a week that $2.25 is worth over $100 a year.
'Smart' answers aside, I fill up with 93 for my APR93. I filled up with 91 when stock. I don't see anywhere that I stated or suggested otherwise.
How do you know that you are getting "a lil more timing out of the money i invested in my chip" ? Have you measured your timing? A car that _never_ pulls timing is one that is likely to be using gas that is too high in octane, and is likely to be suffering from incomplete combustion, overworking the catalytic converter and wasting money.
My argument was that we have _never_ seen a comprehensive study done on octane ratings in these engines. People fall into one of 3 camps - "I'll use the 'best' gas I can", "I'll use the recommended gas only", or (not really here on the 'tex) "I'll use the cheapest gas I can".
You are obviously in the second camp, and quite prepared to spend the rest of your days believing generic recommendations as gospel truth. Fine. It doesn't automatically make your choice of gas right though. I'd like to see some real analysis before I believe that the same octane is required in Alaska and Texas.
Re: Fuel Grade (genixia)
i'm sorry, i completely disagree, especially with your 3 camps. i've measured timing on several apr 91 cars (that have the stock option too) and have found that if you are running anything less than 91, your losing power, significant power. (it's already pulling 7-9's with up to 11 spikes on all cylinders on 91 octane)
i actually have a friend who is pinging on apr91 when on 91 octane, and when mixed with 100 (for testing, has stopped pinging) (he has contacted apr and is working it out with them)
you don't need to pull timing to know your burning all your fuel efficiently, that's just retarded. when tuning my big turbo setup, there is a VERY noticable difference between pulling 4-6 on a few cylinders and having 0 timing pulled (in which, 0 timing pulled is much more powerful) (and this testing was done between 98 octane and 96 octane)
granted, the ideal situation is to run the bare minimum octane possible without detonation, it's just not practical and most people need a water downed answer.
i guess you forgot the camp that actually researches what octane works best with their car.
Modified by nrml at 11:54 PM 7-15-2004
| Quote, originally posted by genixia » |
| How do you know that you are getting "a lil more timing out of the money i invested in my chip" ? Have you measured your timing? A car that _never_ pulls timing is one that is likely to be using gas that is too high in octane, and is likely to be suffering from incomplete combustion, overworking the catalytic converter and wasting money. |
i'm sorry, i completely disagree, especially with your 3 camps. i've measured timing on several apr 91 cars (that have the stock option too) and have found that if you are running anything less than 91, your losing power, significant power. (it's already pulling 7-9's with up to 11 spikes on all cylinders on 91 octane)
i actually have a friend who is pinging on apr91 when on 91 octane, and when mixed with 100 (for testing, has stopped pinging) (he has contacted apr and is working it out with them)
you don't need to pull timing to know your burning all your fuel efficiently, that's just retarded. when tuning my big turbo setup, there is a VERY noticable difference between pulling 4-6 on a few cylinders and having 0 timing pulled (in which, 0 timing pulled is much more powerful) (and this testing was done between 98 octane and 96 octane)
granted, the ideal situation is to run the bare minimum octane possible without detonation, it's just not practical and most people need a water downed answer.
i guess you forgot the camp that actually researches what octane works best with their car.
Modified by nrml at 11:54 PM 7-15-2004
Re: Fuel Grade (genixia)
The inside of my gas door says 91 oct min. Short of one Citgo in my area, 93 octane is impossible to come across. So you're saying by me using 93 octane, I'm not burning my fuel completely? I don't think so.
![Image]()
Granted, if you're puting 100 oct on your STOCK car, you're not benefiting anything unless you have programing to take advantage of the higher octane. But I don't believe your car is going to have trouble burning it.
Modified by UncannySkill at 3:10 PM 7-16-2004
| Quote, originally posted by genixia » |
| How do you know that you are getting "a lil more timing out of the money i invested in my chip" ? Have you measured your timing? A car that _never_ pulls timing is one that is likely to be using gas that is too high in octane, and is likely to be suffering from incomplete combustion, overworking the catalytic converter and wasting money. |
The inside of my gas door says 91 oct min. Short of one Citgo in my area, 93 octane is impossible to come across. So you're saying by me using 93 octane, I'm not burning my fuel completely? I don't think so.
Granted, if you're puting 100 oct on your STOCK car, you're not benefiting anything unless you have programing to take advantage of the higher octane. But I don't believe your car is going to have trouble burning it.
Modified by UncannySkill at 3:10 PM 7-16-2004
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3,197 Posts
Re: Fuel Grade (UncannySkill)
no i havent done any timing logs. i dont have vag-com or a labtop to run it. i have a friend at the dealer that takes care of my needs. I understand what your saying... to a degree.
you are correct by saying running 100 octane in a 91 octane file would probably make the car slower due to incomplete combustion. octane ratings are not indicative or gas quality, but rate at which the fuel combusts. I'm sure in NV where it was 114 the other day with the AC blasting my car benefits from 91 vs 87 or 89. The car will ping on certain brands of gas at WOT. I'll take the 91 as thats what VW calls for stock and i'm not stock so im sure running 91 is advantageous. FWIW im not worried about $100 a yr on gas. If i was i would have bought a toyota Echo or a TDI.
no i havent done any timing logs. i dont have vag-com or a labtop to run it. i have a friend at the dealer that takes care of my needs. I understand what your saying... to a degree.
you are correct by saying running 100 octane in a 91 octane file would probably make the car slower due to incomplete combustion. octane ratings are not indicative or gas quality, but rate at which the fuel combusts. I'm sure in NV where it was 114 the other day with the AC blasting my car benefits from 91 vs 87 or 89. The car will ping on certain brands of gas at WOT. I'll take the 91 as thats what VW calls for stock and i'm not stock so im sure running 91 is advantageous. FWIW im not worried about $100 a yr on gas. If i was i would have bought a toyota Echo or a TDI.
Re: Fuel Grade (RABIDRABBIT1983)
Hehe. Maybe, despite my inability to express myself effectively, I am getting through somehow.
To clarify what I meant by "If you car _never_ pulls timing", I didn't mean on a minute to minute basis, but more on a scenario basis. For instance, if you loaded up your car with 5 fat bloaters and a trunkload of paving slabs, and then tried to drive with a wide open throttle up a long 15% incline on the hottest day of the year in Death Valley, and it didn't pull any timing, then surely your fuel grade cannot be optimal for driving around a pancake flat town with a light load and light foot. Now that scenario may be extreme, but hopefully you understand the sentiment.
I notice that everyone else in this thread represent the worst case locations... South California, Nevada, and Florida. All known for their chilly weather.
![Image]()
| Quote, originally posted by RABIDRABBIT1983 » |
| no i havent done any timing logs. i dont have vag-com or a labtop to run it. i have a friend at the dealer that takes care of my needs. I understand what your saying... to a degree. |
Hehe. Maybe, despite my inability to express myself effectively, I am getting through somehow.
To clarify what I meant by "If you car _never_ pulls timing", I didn't mean on a minute to minute basis, but more on a scenario basis. For instance, if you loaded up your car with 5 fat bloaters and a trunkload of paving slabs, and then tried to drive with a wide open throttle up a long 15% incline on the hottest day of the year in Death Valley, and it didn't pull any timing, then surely your fuel grade cannot be optimal for driving around a pancake flat town with a light load and light foot. Now that scenario may be extreme, but hopefully you understand the sentiment.
I notice that everyone else in this thread represent the worst case locations... South California, Nevada, and Florida. All known for their chilly weather.
Re: Fuel Grade (genixia)
I'm using bad quality 97 octane fuel (no good gas around here in Peru)
Some weeks ago I had a lot of timing pull (timing was advanced due the increased maf housing size 3.1" ID)
![Image]()
![Image]()
Here are the new log made today with the new software version.
Do you guys think I could be making more power if I lower the timing a little more???
![Image]()
![Image]()
I'm using bad quality 97 octane fuel (no good gas around here in Peru)
Some weeks ago I had a lot of timing pull (timing was advanced due the increased maf housing size 3.1" ID)
Here are the new log made today with the new software version.
Do you guys think I could be making more power if I lower the timing a little more???
Joined
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7,767 Posts
Re: Fuel Grade (genixia)
Colorado here
![Image]()
. -10º F cold enough for ya?
![Image]()
| Quote, originally posted by genixia » |
| I notice that everyone else in this thread represent the worst case locations... South California, Nevada, and Florida. All known for their chilly weather.
|
Colorado here
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