US vs Euro fuel
08-22-2007, 10:13 AM
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US vs Euro fuel
I know this has been discussed before in that high octane 93 in the states is about the same as in Europe.
But, I was watching Top Gear the other night and they were reviewing the Konissieg (SICK CAR!!!) and said it makes 700hp or so on US fuel and about "50hp more on EU petrol"
????????
But, I was watching Top Gear the other night and they were reviewing the Konissieg (SICK CAR!!!) and said it makes 700hp or so on US fuel and about "50hp more on EU petrol"
????????
08-22-2007, 03:09 PM
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There are two ways to measure fuel octane. MON and RON.
In the US you add MON and RON and divide by 2. In Europe we just use the RON.
93 "US-Octane" will be more knock-resistant than 93 "Euro-Octane".
Our 98 RON is equal to your 93 octane.
The fuel I run (labelled 99 octane) is 99 RON and 87,5 MON. In the US this would be labelled 93 octane (99 + 87,5 / 2 = 93.25)
In the US you add MON and RON and divide by 2. In Europe we just use the RON.
93 "US-Octane" will be more knock-resistant than 93 "Euro-Octane".
Our 98 RON is equal to your 93 octane.
The fuel I run (labelled 99 octane) is 99 RON and 87,5 MON. In the US this would be labelled 93 octane (99 + 87,5 / 2 = 93.25)
08-22-2007, 03:20 PM
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That's what I thought, but on the show they were inferring that you would make more on EU fuel vs. US fuel. Maybe they were mistaken.
08-22-2007, 04:36 PM
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Well, there's the octane measurement methods and then there's other factors also... for example, a typical 93 octane USA summer blend contains about 1% more energy than a comparable 93 octane USA winter blend...
Also, while the same fuel will give different RON and MON value, [therefore by definition automatically giving different (R+M)/2 values), that doesn't mean that two different fuels with the same octane numbers by either or both given methods will automatically contain the same amount of energy... the US winter blend/summer blend dichotomy is one example of this...
In fact it's quite possible for a different blend to have a slightly different MON but the same RON, or vice-versa This just muddies the 'ease' of comparison still further..
700hp getting increased by "about 50hp" equates to a 7% (700hp x 107% = 749hp) power improvement... I simply refuse to accept that's possible simply by keeping all other things equal (including the fuel's rating on the relative octane scale) except the fuel's nation of origin.
Perhaps either the facts have been misquoted somehwere along the line, or they were using the 'nationality' of the fuel as a handy or perhaps flippant euphemism for running a car on the other side of the Atlantic...
...in which case the emissions requirements would allow the vehicle to run with a rather different tuning... and that would almost certainly allow a difference of that magnitude. That makes a lot more sense to me.
So I don't have anything else to support my conjecture as to how those numbers might be valid, but I certainly don't accept that changing nothing but the nationality of the fuel might allow the Koenigsegg -or any other vehicle- to run so dramatically differently.
After all, VW, Porsche, BMW, Mercedes... they all make vehicles which run fundamentally the same engine mechanicals on both sides of the Atlantic, but they ususally have rather different, nation-specific engine management, or other bolt-on emissions-related castration systems...
Hey Todd, lemme know if you want me to help out with that injector thingie... from what I've read elsewhere here, it sounds like you would indeed be well-advised to put the resistors in.
Keith
Also, while the same fuel will give different RON and MON value, [therefore by definition automatically giving different (R+M)/2 values), that doesn't mean that two different fuels with the same octane numbers by either or both given methods will automatically contain the same amount of energy... the US winter blend/summer blend dichotomy is one example of this...
In fact it's quite possible for a different blend to have a slightly different MON but the same RON, or vice-versa This just muddies the 'ease' of comparison still further..
700hp getting increased by "about 50hp" equates to a 7% (700hp x 107% = 749hp) power improvement... I simply refuse to accept that's possible simply by keeping all other things equal (including the fuel's rating on the relative octane scale) except the fuel's nation of origin.
Perhaps either the facts have been misquoted somehwere along the line, or they were using the 'nationality' of the fuel as a handy or perhaps flippant euphemism for running a car on the other side of the Atlantic...
...in which case the emissions requirements would allow the vehicle to run with a rather different tuning... and that would almost certainly allow a difference of that magnitude. That makes a lot more sense to me.
So I don't have anything else to support my conjecture as to how those numbers might be valid, but I certainly don't accept that changing nothing but the nationality of the fuel might allow the Koenigsegg -or any other vehicle- to run so dramatically differently.
After all, VW, Porsche, BMW, Mercedes... they all make vehicles which run fundamentally the same engine mechanicals on both sides of the Atlantic, but they ususally have rather different, nation-specific engine management, or other bolt-on emissions-related castration systems...
Hey Todd, lemme know if you want me to help out with that injector thingie... from what I've read elsewhere here, it sounds like you would indeed be well-advised to put the resistors in.
Keith
08-22-2007, 09:44 PM
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Top Gear is excellent entertainment, not much more. What they do they do well and manage to capture a very broad audience. But they put more effort into putting up a good show than to getting the facts straight. JC has for example a habit of mentioning torque numbers as "This car has X torques!" not revealing if it is lbs./ft., Nm or squirrel squints..
Btw, the Koenigsegg can be ordered in a 1018 hp E85 version as well.
Btw, the Koenigsegg can be ordered in a 1018 hp E85 version as well.
08-23-2007, 01:01 AM
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First, Anders probably has it right.
But, second, IF the show was right, could it be due to specific emmissions gas requirements for the country in which the test was done? I thought that the EU was actually more stringent in emmissions regulations as opposed to U.S. requirements. Is that an incorrect assumption?
But, second, IF the show was right, could it be due to specific emmissions gas requirements for the country in which the test was done? I thought that the EU was actually more stringent in emmissions regulations as opposed to U.S. requirements. Is that an incorrect assumption?
08-23-2007, 01:47 PM
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First, Anders probably has it right.
But, second, IF the show was right, could it be due to specific emmissions gas requirements for the country in which the test was done? I thought that the EU was actually more stringent in emmissions regulations as opposed to U.S. requirements. Is that an incorrect assumption?
But, second, IF the show was right, could it be due to specific emmissions gas requirements for the country in which the test was done? I thought that the EU was actually more stringent in emmissions regulations as opposed to U.S. requirements. Is that an incorrect assumption?
Exhaust Gas Recirculation, Fuel Injection and even them 'Catholic converters' that I hear so much about, were -I THINK- all mandatory in the US for a good time longer than in Europe.
I bought a car brand new in 1986 which had a carburettor (this was in the UK) whereas over here in the USA I'm pretty sure that would have been completely illegal, or am I off on my timescale...? -Either way, I know that many -if not most- vehicles had higher outputs in UK/European markets than in US trim. This was not due to the fuel though...
Keith
