Gasoline quality - GreenHybrid

eco.conduite.free.fr · #1 (**permalink**) 11-16-2008, 04:17 AM

Hi,

Do you think gasoline in Europe is best or worst than in America or Canada ? I mean, is Eurpean gasoline contains less or more energy than an American or Canadian one ?

In Europe, USA is well known for its crude oil and oil companies... So this question is in my head and I have no answer...

bwilson4web · #2 (**permalink**) 11-16-2008, 03:46 PM

This is an interesting question but difficult to answer without laboratory experimentation. In a perfect world, we'd send our samples to the same lab but mailing even small gasoline samples tends to frowned upon by the postal authorities. To me, the only way that makes sense is to build identical, primitive calorimeters and begin gasoline sample testing and exchanging the results.

If we can both get identical sized, aluminum pie pans and a wick burner, we could put a measured amount of water into the pan and use the wick burner to boil off the water. The amount boiled away should be proportional to the energy content of the gasoline. A simple layer of aluminum foil cover over the pan minimizes evaporation loss.

If you are interested, let's post photos of what is readily available and we'll see what makes sense. I'm interested because my last gasoline tests used my Prius. I was happy with the results but the method was tedious. It was taking a week per sample to get results.

Bob Wilson

eco.conduite.free.fr · #3 (**permalink**) 11-17-2008, 11:07 AM

Quote:

Originally Posted by bwilson4web

This is an interesting question but difficult to answer without laboratory experimentation. In a perfect world, we'd send our samples to the same lab but mailing even small gasoline samples tends to frowned upon by the postal authorities. To me, the only way that makes sense is to build identical, primitive calorimeters and begin gasoline sample testing and exchanging the results.

If we can both get identical sized, aluminum pie pans and a wick burner, we could put a measured amount of water into the pan and use the wick burner to boil off the water. The amount boiled away should be proportional to the energy content of the gasoline. A simple layer of aluminum foil cover over the pan minimizes evaporation loss.

If you are interested, let's post photos of what is readily available and we'll see what makes sense. I'm interested because my last gasoline tests used my Prius. I was happy with the results but the method was tedious. It was taking a week per sample to get results.

Bob Wilson

Hi Bob, I think, It may be very hard to make this experiment !! First, we must have the same kind of gasoline from the same oil companies ! and we need to have the same wirk burner at the same temperature, the same atmospheric condition (wet or not), etc... So it seems to be very difficult to make it !
But I'm sure someone has pieces of the answer ! I'll try to have an answer from one of my friend who works for a French oil companies... !

eco.conduite.free.fr · #4 (**permalink**) 11-24-2008, 12:56 AM

Hi !

I have some information, it seems that gasoline in US and in Europe haven't the same octane rating ! so it'll be very hard to find the same gasoline in Europe and in US to make the experiment...

ice · #5 (**permalink**) 02-17-2009, 04:09 PM

yup i think Octane would be the issue...

bwilson4web · #6 (**permalink**) 02-17-2009, 04:45 PM

Hi,

Actually it turns out that gasoline is a mix of different hydrocarbons. As a general rule, the denser fuels (aka., diesel) have more chemical energy than the lighter fuels (aka., gasoline.) But the lighter fuels have higher energy per unit of mass, which is not density. I'd read about this in one of the USA EPA publications discussing the different energy content of 'winter' versus 'summer' blends.

The way I keep it straight:

denser fuel, more energy - there are more chemical bonds to support energy release (carbon has typically four bonds per atom and molecular mass is proportional to density)
lighter fuel, less energy - fewer chemical bonds but often more energy per gram of fuel (hydrogen is an excellent if rascally fuel.) But fewer bonds per molecule means there isn't that many bonds to release energy.

I hope this helps.

Bob Wilson

attilla1 · #7 (**permalink**) 02-17-2009, 06:04 PM

The answer is "it depends".

Refineries are configured differently, crudes are different and regional product specifications are different at different times of the year.

As mentioned above, denser fuels have more energy per unit volume. Higher octane fuels tend to have lower density, so they tend to have lower energy per unit volume, but they have (by definition) a lower tendency towards preignition.

Probably the biggest driver is ethanol blended in many but not all of the states in the US. Ethanol has only about 70% of the energy per unit volume as gasoline. In states requiring ethanol which is usually blended at 10%, your mileage will be lower because of the lower energy density.

Hope this helps

An oil boiler (refinery engineer)

ice · #8 (**permalink**) 02-18-2009, 07:12 PM

a helpful post! great!

livvie · #9 (**permalink**) 02-19-2009, 11:48 AM

Don't forget same altitude. ;-)

eco.conduite.free.fr · #10 (**permalink**) 03-04-2009, 01:26 AM

Quote:

Originally Posted by attilla1

The answer is "it depends".

Refineries are configured differently, crudes are different and regional product specifications are different at different times of the year.

As mentioned above, denser fuels have more energy per unit volume. Higher octane fuels tend to have lower density, so they tend to have lower energy per unit volume, but they have (by definition) a lower tendency towards preignition.

Probably the biggest driver is ethanol blended in many but not all of the states in the US. Ethanol has only about 70% of the energy per unit volume as gasoline. In states requiring ethanol which is usually blended at 10%, your mileage will be lower because of the lower energy density.

Hope this helps

An oil boiler (refinery engineer)

Hi !
it's very intersting ! In France we have only two kind of unleaded gasoline SP95 (unleaded gasoline with 95 % octane) and SP98 (unleaded gasoline with 98 % octane). The composition of the 5 or 2 % remaining is function of the oil supplyer and of the oil origin.
I understand the less light coponents are in the gasoline , the best milage you can get. So, to compare with US gasolines, it seems that european ones have more energy, the US octane purcentage is lower than in Europe because US gasoline contains a great part of ethanol.

French gouvernement has just authorized the bioéthanol. Some oil supplyers may began to send it in april. This gasoline will be have a lower energy so ?