There are many types of engines and fuels in today’s world that people can use to be more environmentally friendly. For example bio diesel was created because regular diesel fuel was making so much bad emissions that is harming the air quality and the environment. So they create it to help reduce greenhouse gas emissions for diesel vehicles. Diesel engines are more complex than a normal car engine. Instead of spark to start the engine like normal cars, a Diesel engine uses what’s called diesel compression. It’s what you need for the diesel engine to start. Instead of a spark plug it uses compression to heat up the cylinder to ignite the fuel, there is no need for a spark plug. But in the winter when it’s cold, they do have glow plug. All the glow plugs do is heat the cylinder up enough to get the fuel to ignite. Also Diesel engines run at a much higher compression than gas engines do. A diesel engine typically runs 16:1-23:1 or 250-350 psi. (Robert Baker February 2010)
Biodiesel is made from used cooking oil mostly. It can be made from any type of vegetable oil, used or not, but not from petroleum based oils, like motor oil. It has to go through a cleaning process through adding ingredients such as catalyst and methanol. You cannot take straight used vegetable oil and run it through your motor; it will clog the engine and create huge problems. Using biodiesel has been known to make engines run smoother and cleaner. It has higher lubricity content then diesel does and also has a higher cetane value which will increase power not by much but enough to be noticeable on a diesel engine. (Robert Baker February 2010)
Cetane number is actually a measure of a fuel's ignition delay; the time period between the start of injection and start of combustion (ignition) of the fuel. In a particular diesel engine, higher cetane fuels will have shorter ignition delay periods than lower cetane fuels. Diesel fuel lubricity is a measure of diesel fuel's ability to reduce wear on contacting metal surfaces found in fuel pumps and injectors. In the case of diesel engines, fuel pumps and fuel injectors are lubricated by the fuel, so lubricity is a measure of a diesel fuel's ability to prevent wear in these parts.
You can run strait grease through your car but it also has to be cleaned not by chemicals but through micron filters. You also have to heat the grease up enough to become viscous enough to be pushed through the injectors at the correct pressure and spray pattern for the vehicle. It’s a very complicated process to create fuel for diesel because you have to get the mixture just right so the vehicle can run smooth. Here’s the fun part, the used cooking grease that are in millions of restaurants like Chinese restaurants, fast food joints etc; are yours to have so you can convert the stuff into renewable energy. Restaurants will literally give you the grease without questions because they themselves are trying to get rid of the stuff and are desperate to do so.
In conclusion even though diesel has its weak points, so does gas. Diesel cars can be converted to use vegetable oil gas cars cannot. Instead of smelling gas in the morning when you start your car you will smell French fries in the morning. Every time you arrive at the pump you have to pay 20 bucks to fill your tank. But at restaurants, fast foods, Chinese restaurants, they have tons of grease that they are willing to give away they don’t want the stuff you can use that to make the fuel to use for your diesel car. You’re not harming the environment and you’re reliving a problem to restaurants in your area. Everyone wins.