I run a higher octane. Roughly 100 octane. But then, that is because I use E85 primarily in my vehicles. Not throwing any money away. Even when the lower fuel economy of E85, it still saves me about 5 cents a mile on fuel cost compared to using premium or ethanol free regular. and still save a couple of cents per mile compared to regular E10.
Running higher than recommended octane fuel
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Originally Posted By: CT8
What you have to do is run the tank down to a quarter tank then fill with high octane . Run 5 tanks on high octane and see if your mpgs are better. Report back
Some engines will take longer than others to adjust ignition timing (and fuel mixture?) to suit higher octanes, so I agree, that several tanks of fuel may be necessary to establish a sort of 'benchmark.'
If you're the sort that has access to diagnostics equipment, you could probably find a way to take a 'snapshot' of the engine on premium vs regular to compare differences in ignition timing.
For me in the old 320i, I know when its running in the realm of 'properly' as it isn't really that quick, at all. When the ping sensors were 'deaf,' the ignition advance must've gone absolutely nuts as it went a helluva lot quicker. Strange to think whatever variance the stock setup can produce in timing can have such a remarkable difference on acceleration.
A mate of mine runs Premium (98RON) in his late-model Holden Cruze, there is some an improvement in economy, but he notes a night and day difference between Premium and Regular (91RON) in terms of acceleration and performance.
What you have to do is run the tank down to a quarter tank then fill with high octane . Run 5 tanks on high octane and see if your mpgs are better. Report back
Some engines will take longer than others to adjust ignition timing (and fuel mixture?) to suit higher octanes, so I agree, that several tanks of fuel may be necessary to establish a sort of 'benchmark.'
If you're the sort that has access to diagnostics equipment, you could probably find a way to take a 'snapshot' of the engine on premium vs regular to compare differences in ignition timing.
For me in the old 320i, I know when its running in the realm of 'properly' as it isn't really that quick, at all. When the ping sensors were 'deaf,' the ignition advance must've gone absolutely nuts as it went a helluva lot quicker. Strange to think whatever variance the stock setup can produce in timing can have such a remarkable difference on acceleration.
A mate of mine runs Premium (98RON) in his late-model Holden Cruze, there is some an improvement in economy, but he notes a night and day difference between Premium and Regular (91RON) in terms of acceleration and performance.
I'm looking to get my hands on an affordable data logger to definitively answer this question (well, the opposite of your question) for the ATS. The ATS calls for 93 octane, which isn't cheap and only comes in ethanol blended form. I want to try 91 octane non-ethanol (which is available in abundance in my area and for much less $$) and compare the data between the two with respect to timing and the number of knock events under various conditions. If they are statistically close, I'll make the switch to the 91 octane and get better gas mileage (in theory).
Now my van and my bike call for 87 (or higher). They get 87 with a dose of Techron, Gumout, or similar before each oil change.
Now my van and my bike call for 87 (or higher). They get 87 with a dose of Techron, Gumout, or similar before each oil change.
So the inverse to my experiment above would be to plug a data logger in, and gather the data to make a proper decision. If there is no advance in timing, or no decrease in knock events when going from the 87 octane to the 91 octane, there will be no increase in mpg or hp/torque, and therefore you are just paying for peace of mind... which has value for some... I know.... I have spent many years there
Something that has sprang to mind recently with the premium vs regular petrol debate... If people are noticing improved fuel economy, does this stem from the ignition advance improving such that drivers aren't driving around with the accelerator floorboarded and can instead make do with less acceleration? It certainly seems a plausible theory.
OTOH, if people notice improved performance, they might be driving around with their foot buried for the [censored] of it!
OTOH, if people notice improved performance, they might be driving around with their foot buried for the [censored] of it!
Triple_Se7en
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Originally Posted by Nissan101
Are there any disadvantages of running fuel of higher octane, when the manufacture recommends a lower octane.
Thank you.
Don't say its the price. Any other disadvantages?
Your owners manual actually uses the word 'recommends", when discussing fuels in your owners manual? I'm used to Chrysler and GM manuals and they listed octanes in my manual, but refrain from using the word "recommends". My manuals from 14-15, even 25 years ago say 87 octane is needed. Perhaps new vehicles these days have changed the wording.
Personally, use the octane the vehicle runs best on. In my 2003 and 2004 GMs, it's Premium..... runs smoother / idles smoother. Do I buy it all the time/.... heck no. Only when I can find Mobil-Exxon or BP under $3.25 a gallon. That's my wallet limit.
Even my lawmowers and gas weed wackers run better on Premium.
Are there any disadvantages of running fuel of higher octane, when the manufacture recommends a lower octane.
Thank you.
Don't say its the price. Any other disadvantages?
Your owners manual actually uses the word 'recommends", when discussing fuels in your owners manual? I'm used to Chrysler and GM manuals and they listed octanes in my manual, but refrain from using the word "recommends". My manuals from 14-15, even 25 years ago say 87 octane is needed. Perhaps new vehicles these days have changed the wording.
Personally, use the octane the vehicle runs best on. In my 2003 and 2004 GMs, it's Premium..... runs smoother / idles smoother. Do I buy it all the time/.... heck no. Only when I can find Mobil-Exxon or BP under $3.25 a gallon. That's my wallet limit.
Even my lawmowers and gas weed wackers run better on Premium.
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I have read in so many owners manuals to use "minimum 87 octane" or 87 octane or higher" So using a higher octane isn't bad for an engine by any means. Some engines seem to like 87 just fine and won't do any better with 89, 91,93 octane. Then there are the engines that for watever reason give better power or milage results when moving up the octane rating scale. I recently experimented with 91 e10 fuels from my local Costco and have had positive results. Power improved and milage did go up. How much higher does vary from tank to tank but it does go up. Some tanks are 1 mile better and another may be 2 miles better. I use my truck as a contractor satellite installer truck so it has
a ladder rack and ladders strapped to it. The truck can catch some wind with that kind of load and of course effect my milage. The premium fuel seems to still get some better milage for me though.
I am using it in my Ford F150 with a rebuilt 4.6 engine. My brother has the same engine but his is the original one with his truck. During a visit he made recently we discussed our gas uses. He has also been gassing up with premium and has had the same results I have had. So for our personal engines it seems they do like the premium fuels. He does not use Costco fuel. He fuels up with non top tier fuels he can get at any station he is near with a good price. That is usually a Maverick station. Just as a note mine does not do so well with Maverick but I wonder if it could be due to different pressure nozzle diliveries that throw off my milage calculations? I always get less milage with Maverick when I pull into that station. Fill with Costco on the next tank and the milage goes up with the Costco gas.
Anyway that is my experience. I will stay with 91 for awhile. Although E0 gas is a lot lower now. I may try that in my vehicle.
a ladder rack and ladders strapped to it. The truck can catch some wind with that kind of load and of course effect my milage. The premium fuel seems to still get some better milage for me though.
I am using it in my Ford F150 with a rebuilt 4.6 engine. My brother has the same engine but his is the original one with his truck. During a visit he made recently we discussed our gas uses. He has also been gassing up with premium and has had the same results I have had. So for our personal engines it seems they do like the premium fuels. He does not use Costco fuel. He fuels up with non top tier fuels he can get at any station he is near with a good price. That is usually a Maverick station. Just as a note mine does not do so well with Maverick but I wonder if it could be due to different pressure nozzle diliveries that throw off my milage calculations? I always get less milage with Maverick when I pull into that station. Fill with Costco on the next tank and the milage goes up with the Costco gas.
Anyway that is my experience. I will stay with 91 for awhile. Although E0 gas is a lot lower now. I may try that in my vehicle.
Kwik Trip 88 gives a couple mpg better on my newer cars
I just started experiencing detonation in my 2.0L Subaru turbo. It's high mileage (over 200K), so it's probably trying to make diamonds with all the carbon buildup in the combustion chamber. That's probably what's causing my pre-ignition/detonation ping sounds. It wasn't bad enough to make the CEL illuminate, but it definitely was audible.
My mechanic co-worker who ran a repair shop for over 30 years said it was most likely pre-ignition from the carbon buildup in the combustion chamber and/or valve faces. Happens on tired engines at this mileage he said. I believe it, because after that began occurring, he said to try higher octane fuel, which just became available in town. Problem is, it's $8 per 9/10gal.! I put half a tank of 100 Octane in the car, and filled it up with 91 (manufacture recommended). Pinging is gone. Carbon is still there, and isn't going anywhere unless it's removed manually (read: nearly impossible without breaking things further), so a solution was found. Higher octane also helps with high mileage pinging issues.
Pinging in any vehicle will begin to destroy the piston's ring land areas, so you want to mitigate it as quick as possible. My mechanic buddy also has a 67 mustang GT fastback (390 FE engine with an aggressive cam/compression ratio), and he has it detuned quite a bit because he cannot run it on pump gas. It just won't shut off if he leaves it tuned the way it want's to run while trying to use pump gas. He also has a 62 corvette he's had since he was much younger (built it up over the years) and it's got a blower on it, high compression etc. He has issues running that car on pump gas as well. He currently has to mix aviation fuel (when he can get it) and drives it on cruise nights and special occasions, but it's a PIA to get fuel that will run correctly without dieseling and running like crap.
Recently he found a lucas oil product that raises the octane "3 points" (it claimed), and gave it a try. He said it smelled like race fuel when he mixed up some of it for his cars and it ran fine in the corvette. So that product worked. We started looking online at a bunch of products that specifically gave numerical claims on octane boost; actual point increases. We found a product made in the mid-west (Wisconsin or something) where it's illegal to transport large amounts of racing fuel (which this manufacture claims was for track purposes). So they (the manufacture of this product) said they had a problem that needed to be solved.
They were not a big company trying to sell some half-baked marketing driven product to turn a big profit, they were trying to solve this fuel transportation issue, not to mention the issue of questionable fuel quality sold at tracks which destroys cars tuned for higher octane by not delivering on the label's race fuel octane promises. Anyhow, he started a company to develop an additive they could carry in small quantities that was able to raise the octane of normal pump gas to levels needed at the track. They developed a product so concentrated that instead of emptying a 20-30 dollar bottle of octane booster from the local auto parts store into your tank, you could simply add a couple ounces of his additive to 91 octane and get 94-112 octane. I found that with my pinging issue, 2 oz in my 13 gal tank is what it took at each fill up. The math equated out to about $2 or so per fill-up. Much better than half a tank of 100 octane at $8 a gal to get similar or even worse octane mix compared to 2 oz of this product.
We were skeptical at first, so we read as many comments and reviews on the product as we could. This was starting to sound too good to be true. But nobody we found had anything bad to say (for the most part, you can't please everyone). But we bought some, and it's working for me! He just got his in the mail recently, and since he doesn't drive these particular cars as often, he hasn't had a chance to give this additive a try yet, but he's convinced it will work for him too.
It's called "Race Gas". Simple.
My mechanic co-worker who ran a repair shop for over 30 years said it was most likely pre-ignition from the carbon buildup in the combustion chamber and/or valve faces. Happens on tired engines at this mileage he said. I believe it, because after that began occurring, he said to try higher octane fuel, which just became available in town. Problem is, it's $8 per 9/10gal.! I put half a tank of 100 Octane in the car, and filled it up with 91 (manufacture recommended). Pinging is gone. Carbon is still there, and isn't going anywhere unless it's removed manually (read: nearly impossible without breaking things further), so a solution was found. Higher octane also helps with high mileage pinging issues.
Pinging in any vehicle will begin to destroy the piston's ring land areas, so you want to mitigate it as quick as possible. My mechanic buddy also has a 67 mustang GT fastback (390 FE engine with an aggressive cam/compression ratio), and he has it detuned quite a bit because he cannot run it on pump gas. It just won't shut off if he leaves it tuned the way it want's to run while trying to use pump gas. He also has a 62 corvette he's had since he was much younger (built it up over the years) and it's got a blower on it, high compression etc. He has issues running that car on pump gas as well. He currently has to mix aviation fuel (when he can get it) and drives it on cruise nights and special occasions, but it's a PIA to get fuel that will run correctly without dieseling and running like crap.
Recently he found a lucas oil product that raises the octane "3 points" (it claimed), and gave it a try. He said it smelled like race fuel when he mixed up some of it for his cars and it ran fine in the corvette. So that product worked. We started looking online at a bunch of products that specifically gave numerical claims on octane boost; actual point increases. We found a product made in the mid-west (Wisconsin or something) where it's illegal to transport large amounts of racing fuel (which this manufacture claims was for track purposes). So they (the manufacture of this product) said they had a problem that needed to be solved.
They were not a big company trying to sell some half-baked marketing driven product to turn a big profit, they were trying to solve this fuel transportation issue, not to mention the issue of questionable fuel quality sold at tracks which destroys cars tuned for higher octane by not delivering on the label's race fuel octane promises. Anyhow, he started a company to develop an additive they could carry in small quantities that was able to raise the octane of normal pump gas to levels needed at the track. They developed a product so concentrated that instead of emptying a 20-30 dollar bottle of octane booster from the local auto parts store into your tank, you could simply add a couple ounces of his additive to 91 octane and get 94-112 octane. I found that with my pinging issue, 2 oz in my 13 gal tank is what it took at each fill up. The math equated out to about $2 or so per fill-up. Much better than half a tank of 100 octane at $8 a gal to get similar or even worse octane mix compared to 2 oz of this product.
We were skeptical at first, so we read as many comments and reviews on the product as we could. This was starting to sound too good to be true. But nobody we found had anything bad to say (for the most part, you can't please everyone). But we bought some, and it's working for me! He just got his in the mail recently, and since he doesn't drive these particular cars as often, he hasn't had a chance to give this additive a try yet, but he's convinced it will work for him too.
It's called "Race Gas". Simple.
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Lol. Another peddler trying to sell his wares on bitog.
MolaKule
Staff member
Originally Posted by saab92x
...They developed a product so concentrated that instead of emptying a 20-30 dollar bottle of octane booster from the local auto parts store into your tank, you could simply add a couple ounces of his additive to 91 octane and get 94-112 octane. I found that with my pinging issue, 2 oz in my 13 gal tank is what it took at each fill up. The math equated out to about $2 or so per fill-up. Much better than half a tank of 100 octane at $8 a gal to get similar or even worse octane mix compared to 2 oz of this product...
It's called "Race Gas". Simple. Race-gas.com
I looked at the charts posted on the site and nowhere do I see a chemical test or calculation that shows the exact octane rating resulting from the various ratios of the "booster" additive to the various fuels, just a bunch of dyno runs in which one has to go to about 6000+ rpm to see any differences.
And I suspect those minor differences are the result of the PCM advancing spark.
The only booster chemistry I am aware of is methylcyclopentadienyl manganese tricarbonyl.
See my PM to you.
...They developed a product so concentrated that instead of emptying a 20-30 dollar bottle of octane booster from the local auto parts store into your tank, you could simply add a couple ounces of his additive to 91 octane and get 94-112 octane. I found that with my pinging issue, 2 oz in my 13 gal tank is what it took at each fill up. The math equated out to about $2 or so per fill-up. Much better than half a tank of 100 octane at $8 a gal to get similar or even worse octane mix compared to 2 oz of this product...
It's called "Race Gas". Simple. Race-gas.com
I looked at the charts posted on the site and nowhere do I see a chemical test or calculation that shows the exact octane rating resulting from the various ratios of the "booster" additive to the various fuels, just a bunch of dyno runs in which one has to go to about 6000+ rpm to see any differences.
And I suspect those minor differences are the result of the PCM advancing spark.
The only booster chemistry I am aware of is methylcyclopentadienyl manganese tricarbonyl.
See my PM to you.
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This is the "calculator" found on their site, but the bottle shows how much to add to a given octane of pump gas. It's working so far, no more pinging for me.
from their site:
RACE GAS
BLENDING CALCULATOR
2 OUNCES OF RACE GAS
WILL RAISE THE OCTANE OF 1 GALLON OF GASOLINE
4 FULL OCTANE NUMBERS (40 POINTS OF OCTANE).
from their site:
RACE GAS
BLENDING CALCULATOR
2 OUNCES OF RACE GAS
WILL RAISE THE OCTANE OF 1 GALLON OF GASOLINE
4 FULL OCTANE NUMBERS (40 POINTS OF OCTANE).
Originally Posted by MolaKule
I looked at the charts posted on the site and nowhere do I see a chemical test or calculation that shows the exact octane rating resulting from the various ratios of the "booster" additive to the various fuels, just a bunch of dyno runs in which one has to go to about 6000+ rpm to see any differences.
And I suspect those minor differences are the result of the PCM advancing spark.
The only booster chemistry I am aware of is methylcyclopentadienyl manganese tricarbonyl.
I believe that's precisly what they use in their formula.
I looked at the charts posted on the site and nowhere do I see a chemical test or calculation that shows the exact octane rating resulting from the various ratios of the "booster" additive to the various fuels, just a bunch of dyno runs in which one has to go to about 6000+ rpm to see any differences.
And I suspect those minor differences are the result of the PCM advancing spark.
The only booster chemistry I am aware of is methylcyclopentadienyl manganese tricarbonyl.
I believe that's precisly what they use in their formula.
Doesn't MMT foul spark plugs similar to TEL?
MolaKule
Staff member
It does but it also may kill CATS in concentration:
Quote
Manganese Fuel Additive (MMT) Can Cause Vehicle Problems SAE 770655
A manganese fuel additive, MMT, is now being used in many unleaded gasolines to improve their octane quality. Use of MMT at concentrations up to 0.033 g Mn/â„“ (0.125 g Mn/gal) is expected to increase. To determine the effect of MMT on exhaust emission control systems, five cars were tested for 80 000 km (50,000 miles) using a driving schedule which included 113 km/h (70 mph) steady speed driving. In this type of operation, use of MMT caused: plugging of monolithic converters located close to the exhaust manifold; partial plugging of an underfloor bead converter; an increase of hydrocarbon emissions from the engines; and excessive spark plug deposits. However, use of MMT apparently enhanced catalytic converter oxidizing activity and did not substantially affect octane requirement increase. These preliminary data suggest that use of MMT in commercial gasolines may cause problems with exhaust emission control systems now in use.
MMT leaves a dusty red deposit on plugs.
Quote
Manganese Fuel Additive (MMT) Can Cause Vehicle Problems SAE 770655
A manganese fuel additive, MMT, is now being used in many unleaded gasolines to improve their octane quality. Use of MMT at concentrations up to 0.033 g Mn/â„“ (0.125 g Mn/gal) is expected to increase. To determine the effect of MMT on exhaust emission control systems, five cars were tested for 80 000 km (50,000 miles) using a driving schedule which included 113 km/h (70 mph) steady speed driving. In this type of operation, use of MMT caused: plugging of monolithic converters located close to the exhaust manifold; partial plugging of an underfloor bead converter; an increase of hydrocarbon emissions from the engines; and excessive spark plug deposits. However, use of MMT apparently enhanced catalytic converter oxidizing activity and did not substantially affect octane requirement increase. These preliminary data suggest that use of MMT in commercial gasolines may cause problems with exhaust emission control systems now in use.
MMT leaves a dusty red deposit on plugs.
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Odd that the quoted text posted says MMT use causes an increase in hydrocarbon emissions but also enhanced catalytic converter oxidizing activity - appears directionally opposite in effects. Guessing the plugging effect predominates the converter activity effect.
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