Why do larger engines use heavier fuels?
- Thread starter HairyHun
- Start date
So, they're not using less refined oil because it's cheaper but because it has higher boiling point?
I'd assume the higher boiling point is the attribute of lower grade oil but not the reason as to why they are using it.
I could be wrong obviously...
I can only assume engines that produce more heat need fuels that boil at a higher temperature. That way it won't boil before it can combust. The more fractioned the fuel is the lower heat it needs to boil. Like a big ship with a 30k hp engine running at around 2k degrees couldn't use the same fractioned fuel as a car engine that runs around 200 degrees. It would boil out before it even made it to the spark. Jet engines are cold running which is probably why they're fixed somewhere between a car and a diesel. Race cars run a lot hotter which is why they use jet fuel grade which is actually slower burning but produces a bigger combustion(less fractioned = more dense). Propane creates the smallest combustion of all but is the fastest burning, which is why it has to be stored in environments no hotter than 120 degrees.
As far as polishes and chemicals i have no idea there.
As far as polishes and chemicals i have no idea there.
heavier fuels are cheaper because they're more efficient, i.e. better miles to the gallon so its good for long trips (ships, trucks, planes). if you're using 1000 gallons of fuel a day ur gonna want the cheapest stuff (ships use that much easy). thats why trucks use diesel as opposed to regular gas. they do have their downsides tho too- HowStuffWorks "If diesel engines are more efficient, why do most cars have gaso"
it prob a combo of everything here...
heavier generally equals cheaper ( less refining needed ) and also has a higher boiling point as well for those engines that dont have spark plugs and instead rely on pressure to combust the fuel.
heavier generally equals cheaper ( less refining needed ) and also has a higher boiling point as well for those engines that dont have spark plugs and instead rely on pressure to combust the fuel.
this isn't necessarily true, diesel currently costs more than gasoline yet is a heavier fuel. sulphur regulations on many of these heavy fuels drive the cost up.
Diesels tend to have more torque, too.
Yep, you can't run a diesel over the road rig on gasoline, it'll detonate the pistons in nothing flat. Most modern diesels are running 15:1 or higher compression compared to 12:1 or less in a car. Also, the tolerances are larger on the bigger engines, due to heat and expansion, so you need an oil / fuel that can fill those gaps.
Ever use a cheap gasoline in a high performance car and hear a "pinging" or "knocking"? That's the fuel detonating before it's supposed to. It can happen in larger vehicles as well, with crippling effects (think broken pistons / rods).
Ever use a cheap gasoline in a high performance car and hear a "pinging" or "knocking"? That's the fuel detonating before it's supposed to. It can happen in larger vehicles as well, with crippling effects (think broken pistons / rods).
Is it true they put heavier taxes on diesel to offset road repair costs due to truckers?
Yes. Federal diesel taxes are 6 cents higher per gallon than gas, and the average state diesel tax is 1 cent higher.
In Florida:
Gas tax: 16 cents
Diesel tax: 29.60 cents
Some states are equal though
Read awhile back that diesel used to be cheaper than gasoline due to it needing less refining and still does compared to gasoline? One of the reasons that it cost more now than gasoline is due to the added demand. Europe has gone to mostly diesel? I could be wrong it was a couple of years ago that I read such.
That's interesting. I wonder why federal would take a higher tax than state. It's states that are paying for the road maintenance.
federal highway dept. racket, so they can give funding to the states for keeping their drinking age at 21. so a big :action-smiley-052: to the feds. I'm over 21 but it's a dumb law
Basically
• diesel more efficient, up to 50% of energy is used while only 25% in petrol. rest lost as heat.
• diesel has less moving parts, 2 x lifetime of patrol engines
•GAYno electrical so no interference with NAV, important for ships
• fuel itself is cheaper to produce.
• diesel more efficient, up to 50% of energy is used while only 25% in petrol. rest lost as heat.
• diesel has less moving parts, 2 x lifetime of patrol engines
•GAYno electrical so no interference with NAV, important for ships
• fuel itself is cheaper to produce.