Kerosene/Diesel question

[Youare]

I know up here in the NorthEast the "winter blend" diesel fuel ratio at some pumps is posted on the pump. I have seen
70-30 and 50-50 numbers deppending on the cold.

One thing I have heard and noticed is that "winter blend" fuel does not provide the same performance as "summer blend" fuel. I know gasoline is rated in octane, I think diesel is rated in c-tane. I believe winter blend is less volitle than the summer blend or lower c-tane.

I use Power Service conditioner in every tank of fuel both summer and winter. It is supposed to increace c-tane as well as prevent gelling and keep injectors clean. I would think that straight kerosene would give you less power than "diesel" fuel?

Randy

 

[RalphVa]

Pentane, octane and various other straight chain C-H chemicals from oil are usually obtained from units that separate them out by something other than distillation. Depends on how much of the pure components are in the crude and the naphtha from the crude to make it worthwhile.

Some are produced as by-products of cat cracking and other processes used to modify distillates to make more or less gasoline or kerosene from crude, depending on demand and qualities needed.

Ralph

 

[StoneHeartFarm]

How do they get the propane and butane to stay in solution? (Sorry, my chemistry is a little rusty on the finer points.) What keeps it from just bubbling out?

Steve

 

[RalphVa]

Enough butane or propane will dissolve into gasoline to give it the necessary "Reid vapor pressure" to start you car in the winter. There's more in gasoline in the winter time.

The main reason that kerosene doesn't give as much fuel economy as diesel is mainly because it has less #/gallon, and they both have about the same Btu/#, heat energy/pound. Therefore, there's less heat energy/gallon in kerosene.

This, apart from having a cooler exhaust temperature due to high compression ratio, higher heat value is one reason why diesel engines are more efficient that gasoline.

Ralph

 

[mahlers]

Also, the higher compression ratio leads to a higher efficiency.

 

[DMB]

For an absolutely fascinating and detailed look at diesel fuel as well as related products and even some info about engine design go to www.tractorsmart.com which may sound like another tractor forum, but it's actually a Kubota dealer site.
Click on the big red "OPEN" sign which will take you to the Home page. At the top of the Home page click the sign for "Technical Info" and go down to "All about diesel fuel" on the list of topics. Pretty interesting stuff.
DMB

 

[StoneHeartFarm]

So diesel is actually distilled from crude oil, but gasoline is "created" from crude oil and several other flammable/explosive gasses? How consistent is the mix from refinery to refinery? Is there really a difference in brands?

Steve

 

[RalphVa]

The primary component of gasoline is naphtha, a distillate straight from the crude or from other processes like catalytic cracking. Then butane is added for vapor pressure, as well as some chemical additives and dyes. They all have to meet pretty much identical API type specs. Each one may have different ideas as to how well their additives are supposed to work to keep your fuel system clean, etc.

Big companies like Exxon and Shell sell about 2/3 of their product to others who blend in their additives or buy them from Exxon and Shell as a package. Same goes for lubricating oil. Castrol, for instance, doesn't make a drop of base oil but do use their own blend of additives, about 20% of the volume of the oil you put in your vehicle.

Ralph

 

[Larry_T]

Will C Have been running sumer fuel so far put winter blend 2gal.in the other day. will put sumer fuel from know till spring. live in WIS. Larry

 

[StoneHeartFarm]

Is the propane/butane coming out of solution the reason that gas goes stale?

Steve