The Best Fuel?

[WarpSpeed]

every day I encounter people who when asked what they do say "I'm an engineer" and like you they are clearly not....they just think that because they have a cursory knowledge of engineering or worse mechanics, they think they can call themselves and engineer. sadly it is often the fault of their employees who are only too happy to bandy this word about.......and of course those using the erm are always reluctant to admit that they are fooling themselves as well as many others.

however if you are completely unable to take a scientific approach to a subject then it is quite clear you are not an engineer regardless of what labels may have been attached to you.

Amazing you know me so well and yet..................................You don't and not much else either...

[MrRealDeal]

The difference is so close to none that it doesn't matter , changing fuel will change the computers directions to the engine rendering it less effective today to use high octane fuel than 30 years ago. Many high-performance engines are designed to operate with a high maximum compression, and thus demand fuels of higher octane. A common misconception is that power output or fuel efficiency can be improved by burning fuel of higher octane than that specified by the engine manufacturer. The power output of an engine depends in part on the energy density of the fuel being burnt. Fuels of different octane ratings may have similar densities, but because switching to a higher octane fuel does not add more hydrocarbon content or oxygen, the engine cannot develop more power.

[Ace of Pop]

Ive used E85 for the last 12K. Its rare for IMHO to get it wrong,he posted that E85 will return 25-30% less in an earlier post. I can assure you first hand, it doesnt in a new Civic.Admittedly i've only used 95 Gasohol and E20, but would be amazed if Real Stuff added 25-30 % more to the 32k i've done in a short time period.!! 15 KPL + 30%, hmmm, i doubt it. .

[Jerry Cornelius]

The difference is so close to none that it doesn't matter , changing fuel will change the computers directions to the engine rendering it less effective today to use high octane fuel than 30 years ago. Many high-performance engines are designed to operate with a high maximum compression, and thus demand fuels of higher octane. A common misconception is that power output or fuel efficiency can be improved by burning fuel of higher octane than that specified by the engine manufacturer. The power output of an engine depends in part on the energy density of the fuel being burnt. Fuels of different octane ratings may have similar densities, but because switching to a higher octane fuel does not add more hydrocarbon content or oxygen, the engine cannot develop more power.

If a low knock index gasoline is used then the anti-knock sensor is more likely to activate. Especially, when under load.

The ensuing correction from the engine management system takes a finite period. During this period the engine is not running as efficiently as it would if a knock had not occurred. Therefore there must be a loss of power and fuel efficiency for this short period.

If it knocks a lot. It loses a lot.

A higher knock index gasoline would reduce this effect. If not removing it entirely.

Having said that. It’s not an effect that you or I would perceive during normal driving. If we did notice something. There would be a problem with the car or fuel.

Another variance is fuel density. If the refined fuel is of the same density and contains the same level of aromatics, then the energy value of the fuel would be the same. Whether RON 91 or RON 95.

However, gasoline is refined to a tolerance band. Not a singular fixed value. Its refined density is between 0.7 and 0.77kg/l. So there’s a 10% variance in stored energy.

In their claims about premium fuels, manufacturers state that they use gasoline from the higher end of this tolerance.

As almost everything is manufactured to a cost I’m pretty sure there won’t be a 10% differential between RON 91 and RON 95. It may be 5% or lower. However RON 95 gasoline does have a higher stored energy value than RON 91 gasoline.

In truth, the engine management system plays the biggest role in keeping the engine running within its specified design limits under various conditions. The algorithm for this control will take the type(s) of fuel stated within the design into account.

So, if the handbook says RON 91 only, then there won’t be a noticeable difference if you use RON 95. If the handbook says RON 91 and RON 95, there will be a difference. If the handbook says RON 95 only, RON 91 will break your engine.

Jerry

[Ace of Pop]

Clearly, J.C. you are an Engineer.As Warpspeed comented,he dumbs his comments down. I find Redwood Viscosity,in regard to flashpoint in Oils worthy of thought. Flashpoint of say 30 Redwood is safe in Electrical Switchgear.Just wondered what E85 would read, as its Refined Oil Based,and the scale went that Hi. Basically its Bang For Buck. Just mulling things over.

[Jerry Cornelius]

Clearly, J.C. you are an Engineer.As Warpspeed comented,he dumbs his comments down. I find Redwood Viscosity,in regard to flashpoint in Oils worthy of thought. Flashpoint of say 30 Redwood is safe in Electrical Switchgear.Just wondered what E85 would read, as its Refined Oil Based,and the scale went that Hi. Basically its Bang For Buck. Just mulling things over.

Truth is I’m not. But I was before I retired and not from the auto industry.

An engineer is a term very loosely used in the UK where it seemed to me that a job title was very important. However you don’t need to be an academic to be an engineer. Some folks have a wealth of experience and practical knowledge of engineering principles. They’re engineers also and get things done.

Yes, simply put it’s ‘bang for the buck’. But the bang isn’t as big as some profess it to be. You have to make changes to really reap the benefits.

-20 to -29 degrees Celsius for E85 (you can check it on google same as I did). Haven’t got a clue on the redwood but it’ll be in the +ve degree range if it has a flashpoint.

Jerry

[WarpSpeed]

Clearly, J.C. you are an Engineer.As Warpspeed comented,he dumbs his comments down. I find Redwood Viscosity,in regard to flashpoint in Oils worthy of thought. Flashpoint of say 30 Redwood is safe in Electrical Switchgear.Just wondered what E85 would read, as its Refined Oil Based,and the scale went that Hi. Basically its Bang For Buck. Just mulling things over.

Truth is I’m not. But I was before I retired and not from the auto industry.

An engineer is a term very loosely used in the UK where it seemed to me that a job title was very important. However you don’t need to be an academic to be an engineer. Some folks have a wealth of experience and practical knowledge of engineering principles. They’re engineers also and get things done.

Yes, simply put it’s ‘bang for the buck’. But the bang isn’t as big as some profess it to be. You have to make changes to really reap the benefits.

-20 to -29 degrees Celsius for E85 (you can check it on google same as I did). Haven’t got a clue on the redwood but it’ll be in the +ve degree range if it has a flashpoint.

Jerry

Well stated Jerry and the highlighted portion is also very poignant as it's widely forgotten or overlooked that there is a wide range of "specialties" in the "engineering" field, as a matter of further fact there is a wide range of engineering specialties even within that one industry..Only engineers would recognize that fact though.

[wilcopops]

"highlighted portion is also very poignant as it's widely forgotten" - only by WS apparently...."poignant" - really???

[kkerry]

Wilco, do you have any engineering qualifications, please tell us.

[Ace of Pop]

Wilco, do you have any engineering qualifications, please tell us.

Wilco, do you have any engineering qualifications, please tell us.

My Dog has. Kick his arse, and he Makes a Bolt for the Door.

[Kwasaki]

So far the whole range of Fuel,including E85 has no effect on KPL.But i rarely do City driving.Stays at 15.2.

To hot to turn off the engine/air-con in the City while the Mrs shopping and I did 4 km standing still outside the market.

[MrRealDeal]

The difference is so close to none that it doesn't matter , changing fuel will change the computers directions to the engine rendering it less effective today to use high octane fuel than 30 years ago. Many high-performance engines are designed to operate with a high maximum compression, and thus demand fuels of higher octane. A common misconception is that power output or fuel efficiency can be improved by burning fuel of higher octane than that specified by the engine manufacturer. The power output of an engine depends in part on the energy density of the fuel being burnt. Fuels of different octane ratings may have similar densities, but because switching to a higher octane fuel does not add more hydrocarbon content or oxygen, the engine cannot develop more power.

If a low knock index gasoline is used then the anti-knock sensor is more likely to activate. Especially, when under load.

The ensuing correction from the engine management system takes a finite period. During this period the engine is not running as efficiently as it would if a knock had not occurred. Therefore there must be a loss of power and fuel efficiency for this short period.

If it knocks a lot. It loses a lot.

A higher knock index gasoline would reduce this effect. If not removing it entirely.

Having said that. It’s not an effect that you or I would perceive during normal driving. If we did notice something. There would be a problem with the car or fuel.

Another variance is fuel density. If the refined fuel is of the same density and contains the same level of aromatics, then the energy value of the fuel would be the same. Whether RON 91 or RON 95.

However, gasoline is refined to a tolerance band. Not a singular fixed value. Its refined density is between 0.7 and 0.77kg/l. So there’s a 10% variance in stored energy.

In their claims about premium fuels, manufacturers state that they use gasoline from the higher end of this tolerance.

As almost everything is manufactured to a cost I’m pretty sure there won’t be a 10% differential between RON 91 and RON 95. It may be 5% or lower. However RON 95 gasoline does have a higher stored energy value than RON 91 gasoline.

In truth, the engine management system plays the biggest role in keeping the engine running within its specified design limits under various conditions. The algorithm for this control will take the type(s) of fuel stated within the design into account.

So, if the handbook says RON 91 only, then there won’t be a noticeable difference if you use RON 95. If the handbook says RON 91 and RON 95, there will be a difference. If the handbook says RON 95 only, RON 91 will break your engine.

Jerry

Octane ratings are not indicators of the energy content of fuels. It is only a measure of the fuel's tendency to burn in a controlled manner, rather than exploding in an uncontrolled manner.

Here is an example of that : Where the octane number is raised by blending in ethanol, energy content per volume is reduced.

It's an old wives tale that octane rating means more energy.

[Ace of Pop]

The difference is so close to none that it doesn't matter , changing fuel will change the computers directions to the engine rendering it less effective today to use high octane fuel than 30 years ago. Many high-performance engines are designed to operate with a high maximum compression, and thus demand fuels of higher octane. A common misconception is that power output or fuel efficiency can be improved by burning fuel of higher octane than that specified by the engine manufacturer. The power output of an engine depends in part on the energy density of the fuel being burnt. Fuels of different octane ratings may have similar densities, but because switching to a higher octane fuel does not add more hydrocarbon content or oxygen, the engine cannot develop more power.

If a low knock index gasoline is used then the anti-knock sensor is more likely to activate. Especially, when under load.

The ensuing correction from the engine management system takes a finite period. During this period the engine is not running as efficiently as it would if a knock had not occurred. Therefore there must be a loss of power and fuel efficiency for this short period.

If it knocks a lot. It loses a lot.

A higher knock index gasoline would reduce this effect. If not removing it entirely.

Having said that. It’s not an effect that you or I would perceive during normal driving. If we did notice something. There would be a problem with the car or fuel.

Another variance is fuel density. If the refined fuel is of the same density and contains the same level of aromatics, then the energy value of the fuel would be the same. Whether RON 91 or RON 95.

However, gasoline is refined to a tolerance band. Not a singular fixed value. Its refined density is between 0.7 and 0.77kg/l. So there’s a 10% variance in stored energy.

In their claims about premium fuels, manufacturers state that they use gasoline from the higher end of this tolerance.

As almost everything is manufactured to a cost I’m pretty sure there won’t be a 10% differential between RON 91 and RON 95. It may be 5% or lower. However RON 95 gasoline does have a higher stored energy value than RON 91 gasoline.

In truth, the engine management system plays the biggest role in keeping the engine running within its specified design limits under various conditions. The algorithm for this control will take the type(s) of fuel stated within the design into account.

So, if the handbook says RON 91 only, then there won’t be a noticeable difference if you use RON 95. If the handbook says RON 91 and RON 95, there will be a difference. If the handbook says RON 95 only, RON 91 will break your engine.

Jerry

Octane ratings are not indicators of the energy content of fuels. It is only a measure of the fuel's tendency to burn in a controlled manner, rather than exploding in an uncontrolled manner.

Here is an example of that : Where the octane number is raised by blending in ethanol, energy content per volume is reduced.

It's an old wives tale that octane rating means more energy.

Perhaps Calorific Value,would settle things.Do YouRemember the Index of Thermal Efficiency Award, in the 24Hr Le Mans years ago.Sunbeam Tiger won it once,never botherd to find out how it was judged though.

[WarpSpeed]

^Yes actually it's about volatility, combustibility.. A higher octane is more combustible and therefore produces more Hp and smoother power application at a lower volume of fuel per air ratio to achieve stoichiometric. This in turn saves more fuel and is more efficient for the same power output or more.

[MrRealDeal]

Just google it yourselves ..... After you read the first 100 websites telling you one thing you can begin to ask yourself if they are all so wrong why hasn't even one popped up saying the opposite ! LOL

[MrRealDeal]

I really shouldn't out it that way above ..... because the real answer is yes and no ..... higher octane ..... Has nothing to do with it what matters is that your car can burn a higher density of fuel by adding more air in the process, Mercedes and Volvo have cars that do that , the car in question does not. Does higher octane always have more energy even if the car can't use it ? No like I pointed out in the example above with a blended gasoline using ethanol. Is all high octane gas more dense by default than low octane gasoline ? No.... high density gasoline made for race cars is different than the same rating at the gas pump you use , you can buy a denser lower octane racing fuel with more energy in it, than a lower density higher octane rated fuel at the gas pump ....... Why is all that so confusing ? ...... It's not unless you mistakenly believe that Octane rating is even intended to show energy in a gallon of gasoline that's not what it even measures in the first place so it shouldn't be confusing at all.

So the answer is that unless you have a car designed to take advantage of a denser fuel it will do no good anyhow.

Not all high octane fuels are denser than a lower octane fuel so some have a higher ROI with lower potential energy.

Not all equally rated octane fuels are equally dense meaning the exact same octane rating can have a different amount of potential energy in it.

To imply that all high octane fuel is this or that is simply not true unless you are talking about what it actually measures ..... which is that a higher octane fuel will be less likely to detonate without a spark due to compression , that's ALL it measures and that is ALL the inventor of the measurement ever intended it to measure.

[WarpSpeed]

I really shouldn't out it that way above ..... because the real answer is yes and no ..... higher octane ..... Has nothing to do with it what matters is that your car can burn a higher density of fuel by adding more air in the process, Mercedes and Volvo have cars that do that , the car in question does not. Does higher octane always have more energy even if the car can't use it ? No like I pointed out in the example above with a blended gasoline using ethanol. Is all high octane gas more dense by default than low octane gasoline ? No.... high density gasoline made for race cars is different than the same rating at the gas pump you use , you can buy a denser lower octane racing fuel with more energy in it, than a lower density higher octane rated fuel at the gas pump ....... Why is all that so confusing ? ...... It's not unless you mistakenly believe that Octane rating is even intended to show energy in a gallon of gasoline that's not what it even measures in the first place so it shouldn't be confusing at all.

So the answer is that unless you have a car designed to take advantage of a denser fuel it will do no good anyhow.

Not all high octane fuels are denser than a lower octane fuel so some have a higher ROI with lower potential energy.

Not all equally rated octane fuels are equally dense meaning the exact same octane rating can have a different amount of potential energy in it.

To imply that all high octane fuel is this or that is simply not true unless you are talking about what it actually measures ..... which is that a higher octane fuel will be less likely to detonate without a spark due to compression , that's ALL it measures and that is ALL the inventor of the measurement ever intended it to measure.

Lost on that race car analogy again by NOT consuming the entire package of info which clearly states that the engines in question are STOCK engines with little to no mods (as in OEM, not high performance purpose built NASCAR sort of stock engines) therefore the analogy was intended merely as a magnified set of circumstances so it could be better understood.... Once again I guess that was glossed over............

[wilcopops]

I really shouldn't out it that way above ..... because the real answer is yes and no ..... higher octane ..... Has nothing to do with it what matters is that your car can burn a higher density of fuel by adding more air in the process, Mercedes and Volvo have cars that do that , the car in question does not. Does higher octane always have more energy even if the car can't use it ? No like I pointed out in the example above with a blended gasoline using ethanol. Is all high octane gas more dense by default than low octane gasoline ? No.... high density gasoline made for race cars is different than the same rating at the gas pump you use , you can buy a denser lower octane racing fuel with more energy in it, than a lower density higher octane rated fuel at the gas pump ....... Why is all that so confusing ? ...... It's not unless you mistakenly believe that Octane rating is even intended to show energy in a gallon of gasoline that's not what it even measures in the first place so it shouldn't be confusing at all.

So the answer is that unless you have a car designed to take advantage of a denser fuel it will do no good anyhow.

Not all high octane fuels are denser than a lower octane fuel so some have a higher ROI with lower potential energy.

Not all equally rated octane fuels are equally dense meaning the exact same octane rating can have a different amount of potential energy in it.

To imply that all high octane fuel is this or that is simply not true unless you are talking about what it actually measures ..... which is that a higher octane fuel will be less likely to detonate without a spark due to compression , that's ALL it measures and that is ALL the inventor of the measurement ever intended it to measure.

Lost on that race car analogy again by NOT consuming the entire package of info which clearly states that the engines in question are STOCK engines with little to no mods (as in OEM, not high performance purpose built NASCAR sort of stock engines) therefore the analogy was intended merely as a magnified set of circumstances so it could be better understood.... Once again I guess that was glossed over............

WS - give up!

[IMHO]

Is this thread still going?!?!?

Ignore this post and just let it die already

[WarpSpeed]

Is this thread still going?!?!?

Ignore this post and just let it die already

[WarpSpeed]

I really shouldn't out it that way above ..... because the real answer is yes and no ..... higher octane ..... Has nothing to do with it what matters is that your car can burn a higher density of fuel by adding more air in the process, Mercedes and Volvo have cars that do that , the car in question does not. Does higher octane always have more energy even if the car can't use it ? No like I pointed out in the example above with a blended gasoline using ethanol. Is all high octane gas more dense by default than low octane gasoline ? No.... high density gasoline made for race cars is different than the same rating at the gas pump you use , you can buy a denser lower octane racing fuel with more energy in it, than a lower density higher octane rated fuel at the gas pump ....... Why is all that so confusing ? ...... It's not unless you mistakenly believe that Octane rating is even intended to show energy in a gallon of gasoline that's not what it even measures in the first place so it shouldn't be confusing at all.

So the answer is that unless you have a car designed to take advantage of a denser fuel it will do no good anyhow.

Not all high octane fuels are denser than a lower octane fuel so some have a higher ROI with lower potential energy.

Not all equally rated octane fuels are equally dense meaning the exact same octane rating can have a different amount of potential energy in it.

To imply that all high octane fuel is this or that is simply not true unless you are talking about what it actually measures ..... which is that a higher octane fuel will be less likely to detonate without a spark due to compression , that's ALL it measures and that is ALL the inventor of the measurement ever intended it to measure.

Lost on that race car analogy again by NOT consuming the entire package of info which clearly states that the engines in question are STOCK engines with little to no mods (as in OEM, not high performance purpose built NASCAR sort of stock engines) therefore the analogy was intended merely as a magnified set of circumstances so it could be better understood.... Once again I guess that was glossed over............

WS - give up!

[Ace of Pop]

Lost Me, but thats not difficult.Whats it mean, any ideas.?.

[WarpSpeed]

I really shouldn't out it that way above ..... because the real answer is yes and no ..... higher octane ..... Has nothing to do with it what matters is that your car can burn a higher density of fuel by adding more air in the process, Mercedes and Volvo have cars that do that , the car in question does not. Does higher octane always have more energy even if the car can't use it ? No like I pointed out in the example above with a blended gasoline using ethanol. Is all high octane gas more dense by default than low octane gasoline ? No.... high density gasoline made for race cars is different than the same rating at the gas pump you use , you can buy a denser lower octane racing fuel with more energy in it, than a lower density higher octane rated fuel at the gas pump ....... Why is all that so confusing ? ...... It's not unless you mistakenly believe that Octane rating is even intended to show energy in a gallon of gasoline that's not what it even measures in the first place so it shouldn't be confusing at all.

So the answer is that unless you have a car designed to take advantage of a denser fuel it will do no good anyhow.

Not all high octane fuels are denser than a lower octane fuel so some have a higher ROI with lower potential energy.

Not all equally rated octane fuels are equally dense meaning the exact same octane rating can have a different amount of potential energy in it.

To imply that all high octane fuel is this or that is simply not true unless you are talking about what it actually measures ..... which is that a higher octane fuel will be less likely to detonate without a spark due to compression , that's ALL it measures and that is ALL the inventor of the measurement ever intended it to measure.

Lost on that race car analogy again by NOT consuming the entire package of info which clearly states that the engines in question are STOCK engines with little to no mods (as in OEM, not high performance purpose built NASCAR sort of stock engines) therefore the analogy was intended merely as a magnified set of circumstances so it could be better understood.... Once again I guess that was glossed over............

WS - give up!

I have given up.....................................................................................

.........................................................................................On you, that is............