How efficient is a car powered by petroleum?

I am doing a project in class and for the life of me I cannot find any information. My project is about how efficient is a wind/battery powered car and now I have to find wind efficiency vs. petroleum efficiency. Please help!

8 Responses to “How efficient is a car powered by petroleum?”

  1. linlyons Says:

    i think i’ve read that gasoline engines run at about 15% efficiency.
    diesel gets about 30% because of the higher compression ratio.
    the newest power plants approach 50%, but i’m not sure whether that’s using natural gas, coal, or oil.

  2. David Says:

    all cars are powered by petroleum. what do you think gasoline/diesel is? electric cars are charged from power plants. mostly they use coal/ natural gas/ oil as a fuel source. 19% of u.s.a. electrical power in nuclear. less than 2% is wind. wind is not generating any green house gases. it does need a manufactured system to utilize it.

  3. Noah H Says:

    How much energy does it take to find the oil? How much to drill for the oil? How much to build and maintain an oil pipeline to a refinery? How much energy does it take to refine the oil? How much energy does it take to truck the gasoline to a filling station? How much energy is expended on the military force needed to maintain the flow of oil from the middle east? How much energy finally reaches the drive wheels of a car? A gallon of gasoline has X amount of BTU of heat energy. To find the overall energy ratio of a gallon of gasoline to the number of miles a gallon of gas will move a car one mile requires that all of the energy expenses involved in putting that gallon of fuel into any given gas tank be subtracted from the energy finally expended to to do ‘work’…mass moved distance. If I had to guess I’d say it takes the expenditure of 100 BTUs to provide any given vehicle with one BTU of energy. Not very ‘efficient’. Plus of course there’s the added expense of dealing with smog, CO2, and environmental problems not directly associated with moving your car down the road. Something to think about!

  4. Richard Says:

    A gasoline powered car is between 15 and 30% efficient depending on the car. A battery powered car is about 90% efficient.

    That is fuel in the tank and the battery fully charged. That’s not counting transporting the power or fuel.

  5. Breath on the Wind Says:

    Internal combustion engines are "heat engines" and are therefore subject to the laws of thermodynamics. These dictate how efficient an engine can theoretically be. The gasoline engine is roughly 30% efficient and the Diesel is roughly 40% efficient (due to a higher compression ratio) in theory. But your project is not only about the engine but it needs to include some of the industries that power the vehicles.

    The vehicle also may have inefficiencies in its drive train. A gas or diesel vehicle may have a clutch, a transmission, and a rear axle but it is possible to have electric motors directly drive the wheels of an electric car. This will reduce efficiency to around 15 to 20 % for the vehicle. An electric motor can be between 90 to 95% efficient and this may be very close to the final tally in the vehicle. Here is a site that says: "The Roadster’s motor efficiency, battery-to-wheel, is 92% on average and 85% at peak power. For comparison, internal combustion engines have a tank-to-wheel efficiency of about 15%."3

    Finding the efficiency of a petroleum refinery is going to be very difficult. You may have to discover where a refinery gets its energy to refine the oil.1 You will also need to consider the inefficiency of delivering the fuel to a fueling station. And then where are you going to stop? Do you need to also consider the efficiency of delivering crude oil to the refineries and the inefficiencies of defending oil wells along with the exploration and production?

    Electrical production is very different than producing a commodity like fuel. Electricity is a potential.2 It can be easy to make it but if not used the effort can be wasted. Once the wind farm is set up it produces electricity as long as the wind is blowing. If it is not used or not able to be produced what alternative sources or storage must be used to back up this power? There is much talk of using Compressed Air Energy Storage in underground abandoned mines and caves to store energy. But this also has an inefficiency. You may need to consider how much of the time the windmill would suffer from having to use this less efficient source of power.

    Here is a somewhat technical wind efficiency analysis that might be of some help to you: see also for some efficiency numbers:

    But in the end it should be remembered that efficiency is only a way to compare two different but similar processes. Extracting the power of wind from the air which is a relatively "free" source is not quite the same thing as refining oil which comes from a source that must be acquired with some effort and expenditure of funds. If the production facility is to be your starting point (refinery and wind generator) then fairness dictates that some estimate be made for the cost in time, money and defense for obtaining the non domestic product: oil.

  6. Soccer Champion Says:

    To find the overall energy ratio of a gallon of gasoline to the number of miles a gallon of gas will move a car one mile requires that all of the energy expenses involved in putting that gallon of fuel into any given gas tank be subtracted from the energy finally expended to to do ‘work’


  7. Jennifer C Says:

    Less than 10 percent is used in the movement of the car, very ineficient

  8. Military Surplus Shop Says:

    Funny. I was just headed out to grab some stuff like this, and decided to google a some recommendations, yours came up.