The Gasses: Premium, Regular Unleaded or Diesel

Car and truck cost is already costly, but when you add fuel costs it can break the budget. Luckily, you will almost never need anything more expensive than regular low-octane fuel.

There aren’t engine cleaning benefits, and costly gasoline usually doesn’t mean more longevity. It’s just marketing. Check the owner’s manual. If premium is ever needed, it will tell you. If the requirement isn’t there, avoid premium and save yourself the money.

When automobile engines aren’t created for premium gasoline, they never have a use for the higher-octane fuel. It has to do with engine combustion. Premium fuel ignites at a higher temperature, so it can deal with high levels of compression without reigniting. Pricier fuel also has a lower concentration of heptanes, which also makes it less likely to ignite at low temperatures. Even the government regulators agree – there’s no advantage for it in the average tank.

If your owner’s manual does call for premium gas, chances are you don’t always want it. If your car isn’t more than 10 years old, that’s especially the case because of technology that adjusts timing. With premium-designed engines that are intended to use premium fuel, the high-compression fuel can mean better performance. The premium gas also prevents knocking or pinging sounds. However, unless you’re pushing your engine to the max, the difference in engine performance is minimal but the difference in cost is stark. The only exception is for cars that have knocking when regular fuel is being used, even under standard driving conditions. For these vehicles, use your best judgment or speak with our ACE-certified auto experts about using the right fuel.

Can I Try Using Diesel?

While it’s not usually a good idea to use premium gas instead of regular unleaded if you don’t need to, it is vital that you don’t switch between gasoline and diesel. If you drive a diesel, filling up on gas will cause it to fail completely. You’ll need a complete flush. Diesel is a little grimier and much thicker than gas, and diesel vs. gas engines are different in a few ways. Cars designed for diesel don’t use spark plugs. Instead, the fuel is ignited by the heat of compressed air, which is compressed before the fuel is injected directly into the combustion chamber. With gasoline, fuel and air are mixed first and then the spark plugs cause ignition.

Call Christian Brothers Anytime

If you have uncertainties about how to fuel your engine or if you’re having any issues at all with your fuel system, give our trusted team in Edmond, OK a ring. We can help with everything from inspecting cars you’re considering for purchase to maintenance-related spark plug tune-ups or even diagnosis and repair of bigger problems.