Premium gas or no?
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Joined: Jul 2009
Posts: 670
From: SF Bay Area
Sp maybe your engine is outputting 30HP; and the overhead of the engine becomes more of a higher percentage of the energy efficiency equation. So in that sense, yea the lower load you go, the less effect the differences in engine efficiency for is going to have on MPG; cause you're piling up wasted energy everywhere.
So other manufacturers have addressed this with eco-boost or similar mechanisms that shuts down cylinders when more power isn't needed.
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Joined: Aug 2009
Posts: 3,661
From: Georgia
Speaking of which, if there is no difference between regular and premium.. why would you accept that certain high performance applications require premium but when we mention an "econo car" the full cognitive dissonance comes back into play?
You readily admit that a 12.5:1 motor or a turbocharged car would require the octane bump, but in the next breath youll tell us it does nothing and there is no difference?
Talk about cognitive dissonance. Your feeling that higher performance is possible in an economy mark's low end model just through buying higher octane is touching.
Couldn't you provide one article? Just one saying "wow, what a difference" running higher octane rated fuel makes in a car whose manufacturer neither recommends or requires it?
I don't put much stock in articles because this is a techical matter. I don't usually go to Salon to learn more about engine tuning.
Where have I just said wow what a difference.. Do you get tired beating up all those strawmen you create? You are a clown.
Whenever you post "articles" like your favorite qwik trip ad, which says explicitly the only difference is price.. you have shot yourself in the foot. You are just being contrarian at this point, not to mention hypocritical and I think the more you post the more obvious it becomes to the folks sitting on the sidelines.
Where have I just said wow what a difference.. Do you get tired beating up all those strawmen you create? You are a clown.
Whenever you post "articles" like your favorite qwik trip ad, which says explicitly the only difference is price.. you have shot yourself in the foot. You are just being contrarian at this point, not to mention hypocritical and I think the more you post the more obvious it becomes to the folks sitting on the sidelines.
Member
Joined: Aug 2009
Posts: 3,661
From: Georgia
ahhh so now we're talking about performance increases while lugging the engine. I'll have to try that with my auto.
Member
Joined: Aug 2009
Posts: 3,661
From: Georgia
I don't put much stock in articles because this is a techical matter. I don't usually go to Salon to learn more about engine tuning.
Where have I just said wow what a difference.. Do you get tired beating up all those strawmen you create? You are a clown.
Whenever you post "articles" like your favorite qwik trip ad, which says explicitly the only difference is price.. you have shot yourself in the foot. You are just being contrarian at this point, not to mention hypocritical and I think the more you post the more obvious it becomes to the folks sitting on the sidelines.
Where have I just said wow what a difference.. Do you get tired beating up all those strawmen you create? You are a clown.
Whenever you post "articles" like your favorite qwik trip ad, which says explicitly the only difference is price.. you have shot yourself in the foot. You are just being contrarian at this point, not to mention hypocritical and I think the more you post the more obvious it becomes to the folks sitting on the sidelines.
Technical material worth reading is not found in articles and car rags. I don't read any myself as they are often not worth the paper they are printed on.
There is no point providing technical material to a layman. You have no idea what you are looking at in the first place, and already have made up your mind. If actual datalogs won't sway you.. what good would an article or link do?
And while it may be the easiest mod, it is very clearly one of the least understood as you demonstrate day to day.
Car mags get shit wrong all the time.
There is no point providing technical material to a layman. You have no idea what you are looking at in the first place, and already have made up your mind. If actual datalogs won't sway you.. what good would an article or link do?
And while it may be the easiest mod, it is very clearly one of the least understood as you demonstrate day to day.
Car mags get shit wrong all the time.
Last edited by DiamondStarMonsters; Mar 1, 2012 at 03:15 PM.
Member
Joined: Aug 2009
Posts: 3,661
From: Georgia
Technical material worth reading is not found in articles and car rags. I don't ready any myself as they are often not worth the paper they are printed on.
And while it may be the easiest mod, it is very clearly one of the least understood as you demonstrate day to day.
Car mags get shit wrong all the time.
And while it may be the easiest mod, it is very clearly one of the least understood as you demonstrate day to day.
Car mags get shit wrong all the time.
Technical material is found in journals like the one the SAE publishes. It has the added advantage of being peer reviewed.
Thats not what I said, but sure lets go with that. First: Define performance.
Thats a non-answer and a loaded statement all in one! Going for extra credit there?
Also, on what planet do you live where a statement in the manual its self warning of the dangers of using less than 87AKI is not equivalent to a recommendation of using 87 or greater?
Nowhere have I said these engines require premium either. In fact, as stated ad nauseam.. I dont care what you use. my contention is with the flood of fallacies pouring off your fingers and onto the forum. We have enough misinformation as it is.
You should get a job with Fox News for the amount of effort and spin required there.
Also, on what planet do you live where a statement in the manual its self warning of the dangers of using less than 87AKI is not equivalent to a recommendation of using 87 or greater?
Nowhere have I said these engines require premium either. In fact, as stated ad nauseam.. I dont care what you use. my contention is with the flood of fallacies pouring off your fingers and onto the forum. We have enough misinformation as it is.
You should get a job with Fox News for the amount of effort and spin required there.
Last edited by DiamondStarMonsters; Mar 1, 2012 at 03:33 PM.
Member
Joined: Aug 2009
Posts: 3,661
From: Georgia
Statistically significant changes in vehicle fuel economy were measured for vehicles that ran on different fuel grades.
Is it worth $23 to shut me up?
Nope. This is the internet. It is your right, nay.. your duty, to be loud, ignorant and proud.
Also, even though that implies it supports what I am trying to tell you.. it is still a single source.
You are never going to find the answer you want. This is a subject with so many variables to control and account for in the lab, let alone the real world, that there is nothing black and white about it. There is no universal answer.
Your posts suggest you want something definitive, final and entirely conclusive. It doesn't work that way, and I can see where that can be frustrating or seem to reveal what you deem as weak points or holes in my explanations. But it is all about context and details, the stuff you are glossing over in your crusade to "prove" the situation one way or the other across the board.
In much the same way there is no single formula for tuning a given fuel type, fuel grade is not beholden to a single stereotype.
It's like how you can take ten engines entirely identical in every conceivable fashion and find that a few respond better to more timing.. some make better power and run more efficiently with tweaks to the fueling scheme, some are all about airflow and some are combinations of the three.. and yet still one or two could just prove to be stubborn on every front.
Fuel grade is but one, albeit significant, part of the whole equation.
Much of this is indecipherable even to the people who have spent years in the field.
This is what I have been saying from the beginning over a year and a half ago at this point. You can go back and find quotes from me acknowleding that the context is key, and some people will indeed see better results on regular based on their particular operation habits, environment, commute and the condition and quirks of their particular engine/trans/ECU/drivelines.
Most will be able to see gains of some sort with premium, and some of those may find the difference in performance or cost negligible.
Fuel Economy is such an involved subject there is a reason we aren't all driving cars that can pass emissions, do 0-60 in 4 seconds and achieve 100mpg while accomplishing everything else we need them too. Try to open your mind a bit. I would like to believe you can be a rational flexible person but you have done everything conceivable to this point to convince us otherwise.
Because I have a better grasp on this than most its why I go to lengths to explain it and I can take advantage of what I know and return EPA rated or better mileage on almost every tank, even with the manner in which I drive which is admittedly "spirited" more often than not. I run premium fuel which I know contains more toluene than most and contains no ethanol, as well as consisting of other detergents and top cylinder lubes. In my area, Regular is $4.06 today and $4.26 for premium at the station I use most frequently. I run a bigger gap on colder plugs that I have indexed to face the incoming charge 15* off center on the intake side of the head towards the non-VTEC valve with the airbox insulated.
The FIC (which I had installed before, during and after my first turbo system on the car corroborated) what I can see on my gas receipts, feel in the seat and hear from the engine and smell coming out the tail pipe. I have posted up direct numbers pulled from the logs with the FIC when I was NA.
The AEM EMS should be going on soon enough as well to provide yet more data and flexibility in the tune.
I have actual data, straight from the horses mouth (in this case an L15A1) on my side in addition to countless class, lab and field hours to back what I am saying vs you the internet expert with a grudge.
Also, even though that implies it supports what I am trying to tell you.. it is still a single source.
You are never going to find the answer you want. This is a subject with so many variables to control and account for in the lab, let alone the real world, that there is nothing black and white about it. There is no universal answer.
Your posts suggest you want something definitive, final and entirely conclusive. It doesn't work that way, and I can see where that can be frustrating or seem to reveal what you deem as weak points or holes in my explanations. But it is all about context and details, the stuff you are glossing over in your crusade to "prove" the situation one way or the other across the board.
In much the same way there is no single formula for tuning a given fuel type, fuel grade is not beholden to a single stereotype.
It's like how you can take ten engines entirely identical in every conceivable fashion and find that a few respond better to more timing.. some make better power and run more efficiently with tweaks to the fueling scheme, some are all about airflow and some are combinations of the three.. and yet still one or two could just prove to be stubborn on every front.
Fuel grade is but one, albeit significant, part of the whole equation.
Much of this is indecipherable even to the people who have spent years in the field.
This is what I have been saying from the beginning over a year and a half ago at this point. You can go back and find quotes from me acknowleding that the context is key, and some people will indeed see better results on regular based on their particular operation habits, environment, commute and the condition and quirks of their particular engine/trans/ECU/drivelines.
Most will be able to see gains of some sort with premium, and some of those may find the difference in performance or cost negligible.
Fuel Economy is such an involved subject there is a reason we aren't all driving cars that can pass emissions, do 0-60 in 4 seconds and achieve 100mpg while accomplishing everything else we need them too. Try to open your mind a bit. I would like to believe you can be a rational flexible person but you have done everything conceivable to this point to convince us otherwise.
Because I have a better grasp on this than most its why I go to lengths to explain it and I can take advantage of what I know and return EPA rated or better mileage on almost every tank, even with the manner in which I drive which is admittedly "spirited" more often than not. I run premium fuel which I know contains more toluene than most and contains no ethanol, as well as consisting of other detergents and top cylinder lubes. In my area, Regular is $4.06 today and $4.26 for premium at the station I use most frequently. I run a bigger gap on colder plugs that I have indexed to face the incoming charge 15* off center on the intake side of the head towards the non-VTEC valve with the airbox insulated.
The FIC (which I had installed before, during and after my first turbo system on the car corroborated) what I can see on my gas receipts, feel in the seat and hear from the engine and smell coming out the tail pipe. I have posted up direct numbers pulled from the logs with the FIC when I was NA.
The AEM EMS should be going on soon enough as well to provide yet more data and flexibility in the tune.
I have actual data, straight from the horses mouth (in this case an L15A1) on my side in addition to countless class, lab and field hours to back what I am saying vs you the internet expert with a grudge.
Last edited by DiamondStarMonsters; Mar 1, 2012 at 04:35 PM.
Member
Joined: Aug 2009
Posts: 3,661
From: Georgia
So what that all boils down to is:
Change "most" to "some" and we're close.
...some people will indeed see better results on regular based on their particular operation habits, environment, commute and the condition and quirks of their particular engine/trans/ECU/drivelines.
Most will be able to see gains of some sort with premium, and some of those may find the difference in performance or cost negligible.
Most will be able to see gains of some sort with premium, and some of those may find the difference in performance or cost negligible.
Member
Joined: Dec 2011
Posts: 143
From: Colorado
Vehicle fuel consumption and its relationship to fuel ON were measured on 5 relatively modern
vehicles by Shell (Beck, et al., 2006, Ref. 40). Vehicles were tested on a chassis dynamometer 20
with a variety of SGB fuels, but the ONR of the vehicles was not specified. The paper found that
vehicle fuel consumption (FC) could be modeled as a (negative) exponential function of the fuel
octane index, OI, and that the model explained over 80 percent of the fuel consumption
variability. Paired comparisons indicate statistically significant FC improvements for all vehicles
tested when fuel RON increases from 91 to 95. The paper did not indicate whether the vehicles
were equipped with a knock sensor.
vehicles by Shell (Beck, et al., 2006, Ref. 40). Vehicles were tested on a chassis dynamometer 20
with a variety of SGB fuels, but the ONR of the vehicles was not specified. The paper found that
vehicle fuel consumption (FC) could be modeled as a (negative) exponential function of the fuel
octane index, OI, and that the model explained over 80 percent of the fuel consumption
variability. Paired comparisons indicate statistically significant FC improvements for all vehicles
tested when fuel RON increases from 91 to 95. The paper did not indicate whether the vehicles
were equipped with a knock sensor.
40. Beck, et al., Shell, SAE 2006-01-3407
The Impact of Gasoline Octane on Fuel Economy in Modern vehicles
Vehicles: 5 European models (~MYR 1995- 2000), 3 DI and 2 MPFI no details given
Fuels: 14 fuels from the Kalghatgi paper SAE 2001-01-3585 varying from 88 to 99.4 RON
and sensitivity from 1.4 to 11.
Test conditions; 3 vehicles and 10 fuels on chassis dyno, Shell drive cycle, Artemis drive
cycle and US06 and 3 vehicles on 2 fuel pairs on same cycles.
Important figures: 4, 5, 6, and Table 3
Major findings
‐ Fuel consumption could be fitted to a curve FC = A + B exp C*OI and curve explains 80
to 90% of fuel related FC variability for each car.
‐ Paired comparisons indicate statistically significant FC improvements for all 3 vehicles
between 91 and 95 RON fuels but improvement is a function of both drive cycle and
vehicle.
The Impact of Gasoline Octane on Fuel Economy in Modern vehicles
Vehicles: 5 European models (~MYR 1995- 2000), 3 DI and 2 MPFI no details given
Fuels: 14 fuels from the Kalghatgi paper SAE 2001-01-3585 varying from 88 to 99.4 RON
and sensitivity from 1.4 to 11.
Test conditions; 3 vehicles and 10 fuels on chassis dyno, Shell drive cycle, Artemis drive
cycle and US06 and 3 vehicles on 2 fuel pairs on same cycles.
Important figures: 4, 5, 6, and Table 3
Major findings
‐ Fuel consumption could be fitted to a curve FC = A + B exp C*OI and curve explains 80
to 90% of fuel related FC variability for each car.
‐ Paired comparisons indicate statistically significant FC improvements for all 3 vehicles
between 91 and 95 RON fuels but improvement is a function of both drive cycle and
vehicle.
REVIEW TO DETERMINE THE BENEFITS OF INCREASING OCTANE NUMBER ON GASOLINE ENGINE EFFICIENCY
Also you might be interested in this part of a Shell press release which summarizes that paper as
He added, “There is also a misconception that the lowest-priced grade of unleaded petrol, that is 92-octane fuel, is the most economical. That is not necessarily the case. Shell’s research and other studies* have confirmed that adaptive engine management systems found in modern cars, such as knock sensors, lead to better fuel efficiency when higher-octane fuels are used.”
A research paper published by the Society of Automotive Engineers in 2006, “The Impact of Gasoline Octane on Fuel Economy in Modern Vehicles”, investigated and compared 91-octane and 95-octane fuels with respect to fuel efficiency. The results showed that higher-octane fuels led to better fuel economy in all tested cars and in three different driving cycles. Fuel economy benefits varied from 0.9 to 4.3 per cent when switching from 91-octane to 95-octane fuel.
A research paper published by the Society of Automotive Engineers in 2006, “The Impact of Gasoline Octane on Fuel Economy in Modern Vehicles”, investigated and compared 91-octane and 95-octane fuels with respect to fuel efficiency. The results showed that higher-octane fuels led to better fuel economy in all tested cars and in three different driving cycles. Fuel economy benefits varied from 0.9 to 4.3 per cent when switching from 91-octane to 95-octane fuel.
Last edited by komafit; Mar 1, 2012 at 07:04 PM.
Kwiktrip debunks Shell time and time again, just need to read their article and believe it as the holy grail. I'm positive Kwiktrip is doing multi-faceted R&D around the world like the other "BIG" players.
This one is a bit salty flavored, the sarcasm that is. An ECU can not comprehend what is being fed into the car, afterall 87 is exactly the same as 93 except you pay more for the 93. Isn't that correct?
This one is a bit salty flavored, the sarcasm that is. An ECU can not comprehend what is being fed into the car, afterall 87 is exactly the same as 93 except you pay more for the 93. Isn't that correct?
Member
Joined: Aug 2009
Posts: 3,661
From: Georgia
That's cool; thanks for digging that out. It supports Mahout's statement of 2-3% improvement for Fits.
Member
Joined: Dec 2011
Posts: 782
From: WV
In regards to Shell, it appears that move was made to make a little more moo-la. 
Singapore Car Guide: Shell to shut tap on budget fuel
Singapore Car Guide: Shell to shut tap on budget fuel
Shell's fuel technology manager (Asia Pacific) Eric Holthusen added that drivers can expect a 2 per cent improvement in economy if they switch from 92 to 95 - if the car owner's manual recommends 95 in the first place.
ExxonMobil remains committed to lower-grade fuels. Its retail manager Loh Chee Seng said octane value has 'very minimal effect on vehicle mileage'.
Mr Philip Chee, product engineering manager at American oil company Chevron, which makes the Caltex brand of fuels, said a car designed to run on 92 will not gain from higher octane fuels. He notes that 95-octane petrol has a slightly higher energy content than 92, but the difference is no more than 3 per cent.
Mr Philip Chee, product engineering manager at American oil company Chevron, which makes the Caltex brand of fuels, said a car designed to run on 92 will not gain from higher octane fuels. He notes that 95-octane petrol has a slightly higher energy content than 92, but the difference is no more than 3 per cent.