What Fuel Should You Use? Gas, Diesel, or Something Else? Let’s Break It Down!

Ever stood at the pump, staring at those numbers—87, 89, 91—wondering if your car really cares? Or maybe you've thought, "Should I be fancy and get premium?" Spoiler alert: your car might not even care. But knowing what fuel to use (and why) can actually save you money, improve performance, and keep your engine running longer. So, let’s dive in!

Gasoline: Regular vs. Premium – Do You Really Need the Expensive Stuff?

Most gas stations offer at least three options:

• Regular (87 octane) – The go-to for most cars. If your owner’s manual says “regular,” save your money—premium won’t do anything extra.

• Mid-Grade (89 octane) – A middle ground. Some engines might benefit from it, but most don’t need it.

• Premium (91-93 octane) – Required for certain high-performance or turbocharged engines. If your manual says “premium required,” don’t cheap out—you could damage your engine.

🚗 Fun Fact: Higher octane doesn’t mean “better” gas. It just burns differently to prevent knocking in high-performance engines. If your car doesn’t need it, you’re just giving the gas station extra money for no reason!

Diesel – Why Trucks Swear By It

Diesel fuel is totally different from gasoline, and if you accidentally put diesel in a gas car (or vice versa), well… you're in for a very expensive mistake. But for the right vehicles, diesel has some big advantages:

✅ More energy per gallon – Meaning better fuel economy for long hauls.

✅ More torque – That’s why diesel trucks can tow big loads.

✅ Durability – Diesel engines are built tough and can last a long time.

🚛 If you drive a diesel truck, use diesel. No experiments!

Ethanol Blends – What’s the Deal with E85?

Ethanol is an alcohol-based fuel made from corn (yes, your car can technically run on corn). Most gas already contains 10% ethanol (E10), but E85 (85% ethanol) is a thing, too.

🚗 Pros: Burns cleaner than gasoline, reduces emissions, and can increase octane.

⛽ Cons: Lower energy content means worse fuel economy. Your tank empties faster!

💡 Important: Only flex-fuel vehicles can handle E85. If your car isn’t labeled for it, stick to regular gas.

Alternative Fuels – Are They Worth It?

For the eco-conscious or fleet managers thinking outside the box, here are a few other options:

🔹 Biodiesel (for diesel engines) – Made from vegetable oils, renewable, but not always available.

🔹 Propane & CNG (compressed natural gas) – Used in some fleet vehicles, cleaner-burning, but requires special fueling stations.

🔹 Electricity (EVs) – Zero emissions, but range and charging infrastructure matter.

How Do You Know Which Fuel Your Car Needs?

Before you start playing mad scientist at the pump, follow these simple steps:

✅ Check your owner’s manual – It tells you exactly what fuel to use.

✅ Look inside the gas cap – Many cars have a sticker that says if premium is required.

✅ Pay attention to engine performance – Knocking or rough idling? You might be using the wrong fuel.

Case Studies – Science Backs This Up!

📌 High-Octane Myths – A Fuel journal study found that using premium fuel in cars designed for regular gas had zero benefits. (Source)

📌 Ethanol’s Impact – A ScienceDirect study found that E30 (30% ethanol) didn’t cause immediate issues in regular cars, but long-term effects on engine wear were unknown. (Source)

📌 Fleet Fueling Strategies – A report by Chevin Fleet Solutions shows that choosing the right fuel for fleet vehicles can cut costs and improve efficiency. (Source)

The Bottom Line

Stick with the fuel your car is designed for. If it says regular, use regular. If it says premium required, don’t cheap out. And if you’re thinking about alternative fuels, weigh the pros and cons before switching.

💬 What fuel do you use? Ever made a fueling mistake? Tell us in the comments!