Which grade of gas should i use

Oak Ridge National Laboratory. Prakash, A. Octane Response of Premium-Recommended Vehicles. SAE Technical Paper , doi Cracknell, V. Natarajan, D. Doyle et al. Understanding the Octane Appetite of Modern Vehicles. West, B. Huff, L. Moore, M. DeBusk, and S. Department of Energy and the U. Environmental Protection Agency. DOE and the U. Toggle navigation. Selling your car? We can help you advertise its mpg. Vehicles produce about half of the greenhouse gases from a typical U.

We can help you calculate and track your fuel economy. Is this correct? When your cars engine with carburetor is tuned for sea level driving, the gasoline octane rating should be determined on the compression ratio of the engines combustion chamber.

The carbureted engine will start to smoke black smoke, too much fuel and start running erratically! Old hot rodders such as myself always carry a case with different sized main jets, and stop before the erratic behavior begins. This is where you better have knowledge of how to disassemble your carb and reassemble it after changing jets. You want less fuel and more air, then a timing light to retard your distributors spark a few degrees.

Simple eh? What does change the octane numbers in your gas is sudden stops,and sloshing around in a tank without baffles or foam blocks to keep the gas from doing the Big Slosh!! I love my car and all of the tips and tricks that are on this site are very informative, thank you. I have a Ford f 5. When you activate the ignition, this creates a spark that ignites the compressed air and fuel mixing in your engine, which is what allows the gas to power your car.

Sometimes this mixture can ignite prematurely, a phenomenon known as preignition, which is signaled by a knocking sound coming from the engine. Modern cars usually have knock sensors that prevent this. The octane of your gasoline has nothing to do with how much energy is in the fuel. It is a measure of how easily your air-fuel mixture ignites. Higher octane means the gasoline you are using has a greater resistance to preignition. That is to say, it requires greater agitation to ignite it.

That is all that the octane level indicates. Many premium cars generate greater power by using a higher fuel-air compression ratio in the engine. Because the mixture is more compressed, it generates more heat and thereby is more likely to ignite early.

Higher octane gasoline is more resistant to this problem. Your gas cap or instructions near the gas cap should indicate if your car requires premium fuel. If your car requires premium gas and you use a lower octane like 87, you can expect knocking, preignition and engine damage particularly if you have an older model vehicle. If you have a modern car, your knock sensor will kick in to prevent preignition, but this will reduce your engine power and diminish fuel economy, so you will lose more money than you save by using the cheaper gas.

Gasoline is mainly used as an engine fuel in vehicles. Petroleum refineries and blending facilities produce motor gasoline for sale at retail gasoline fueling stations. There are three different types of gas at most U.

You might also see the different gas grades referred to as unleaded, super, or super-premium. Using the right fuel for your vehicle can boost its performance and efficiency. It could even potentially damage your vehicle if you fill up with the wrong type of gas.