If you’ve ever had someone swear by premium fuel, or have a vehicle enthusiast in the family, you’ve probably had a debate or two at the gas pump. Some people believe premium gasoline is always better. Others won’t spend a penny more than they have to. So, who’s right?
The answer is… both.
Unlike many manufacturers that recommend the same fuel for nearly every vehicle, the Chrysler, Dodge, Jeep, Ram and FIAT family includes everything from fuel-efficient commuter vehicles and work trucks to high-performance muscle cars, luxury SUVs, diesel trucks and fully electric vehicles. That means the right fuel depends on what you’re driving.
The good news is that choosing the correct fuel isn’t nearly as complicated as it looks when you’re standing at the pump.
The Best Fuel Isn’t Always the Cheapest… or the Most Expensive
One of the biggest misconceptions in the automotive world is that premium gasoline is simply “better” gasoline. It isn’t.
- Premium fuel isn’t cleaner.
- It doesn’t contain more energy.
- It doesn’t automatically make your engine last longer.
Instead, the best fuel is the fuel your vehicle’s engineers designed it to use.
Putting premium gasoline in a Jeep Compass usually won’t make it perform any better. On the other hand, putting regular gasoline into a Wrangler 392 or another high-performance engine isn’t doing it any favors. Think of fuel like prescription medicine. The correct prescription works best. Taking more doesn’t necessarily improve the results.
A Simple Guide to Fuel Recommendations
Fortunately, choosing the correct fuel doesn’t have to be confusing.
| Fuel Type | Typical Chrysler, Dodge, Jeep, Ram, Fiat Vehicles |
| 87 Regular Unleaded | Most Jeep Compass, Cherokee, Wrangler, Gladiator, Grand Cherokee V6, Chrysler Pacifica, Ram 1500 Pentastar V6, Ram ProMaster, FIAT 500L |
| 89 Mid-Grade | Many HEMI® V8-powered Ram trucks and Dodge/Jeep SUVs |
| 91+Premium | Wrangler 392, SRT® models, Grand Wagoneer Hurricane, Ram 1500 Hurricane High Output, FIAT 500X, FIAT 500 Abarth, FIAT 124 Spider |
| Ultra Low Sulfur Diesel (ULSD) | Ram 2500 & 3500 Cummins® Turbo Diesel trucks, EcoDiesel-equipped Jeep and Ram models |
| Electricity | Jeep Recon, Wagoneer S, FIAT 500e |
Important: Always check your owner’s manual and the label inside your fuel door for your specific vehicle. Different engines and trim levels can have different fuel recommendations.
Why Do Some Vehicles Need Premium Fuel?
This is where many people get confused. Premium gasoline isn’t designed to make an engine more powerful. Instead, it helps prevent engine knock in engines that produce very high cylinder pressures.
For example, a Jeep Compass develops around 200 horsepower and is engineered to run efficiently on regular 87-octane gasoline. Compare that to a Wrangler 392 with its legendary 6.4-liter HEMI V8 producing approximately 470 horsepower, or the new Grand Wagoneer equipped with Stellantis’ twin-turbo Hurricane engine producing well over 500 horsepower. Those engines generate dramatically higher combustion pressures, requiring gasoline with greater resistance to premature combustion. That’s exactly what premium fuel provides.
Premium gasoline isn’t a luxury. It’s simply the correct fuel for certain high-performance engines.
What Is Octane?
Octane is one of the most misunderstood words you’ll see at the gas station. Here’s the simple explanation:
Octane measures a gasoline’s resistance to premature combustion inside the engine.
Higher octane does not mean:
- More horsepower
- Better quality gasoline
- Cleaner fuel
- Longer engine life
It simply means the fuel is better suited for engines designed to operate under higher pressures. That’s why so many Chrysler, Dodge, Jeep and Ram vehicles are perfectly happy using regular gasoline, while certain HEMI®, Hurricane and SRT® engines are engineered for premium fuel.
What About Mid-Grade Gasoline?
Many HEMI-powered trucks and SUVs recommend 89-octane mid-grade gasoline.
Can they operate on 87? In many situations, yes. Modern engine computers can adjust ignition timing to compensate for lower octane. However, using the recommended 89-octane fuel allows the engine to perform as its engineers intended, especially while towing, climbing mountains or accelerating under heavy loads. If your owner’s manual recommends 89 octane, that’s still the best choice.
Diesel Is a Completely Different Fuel
Ram’s legendary Cummins® Turbo Diesel trucks don’t use gasoline at all. They require Ultra Low Sulfur Diesel (ULSD).
Diesel engines ignite fuel differently than gasoline engines. Gasoline engines use spark plugs. Diesel engines ignite fuel through extremely high compression. Because of this completely different design, gasoline should never be pumped into a diesel vehicle, and diesel should never be pumped into a gasoline-powered vehicle.
What Happens If You Accidentally Put Diesel Into a Gasoline Vehicle?
It happens more often than you might think.
If you accidentally pump diesel into your gasoline-powered vehicle:
- Don’t start the engine.
- If the mistake is caught before starting the vehicle, repairs are often limited to draining the fuel tank and flushing the fuel system.
- Once the engine has been started, diesel fuel can circulate through the injectors, fuel lines and spark plugs, increasing the cost of repairs.
- The sooner the mistake is discovered, the better.
What About FIAT Vehicles?
Although FIAT models make up a smaller portion of our inventory, they follow exactly the same rule as every other vehicle we sell. Use the fuel recommended by the manufacturer.
Some FIAT models, including the FIAT 500X, FIAT 500 Abarth and FIAT 124 Spider, feature turbocharged performance engines that recommend premium gasoline to deliver their intended performance. Others, like the FIAT 500L, are engineered to operate on regular 87-octane gasoline. The all-electric FIAT 500e doesn’t visit the gas station at all.
Once again, the best fuel isn’t the most expensive fuel—it’s simply the fuel your vehicle was designed to use.
Buying a Used Vehicle? Don’t Guess.
One advantage of shopping at Mount Airy Chrysler Dodge Jeep Ram FIAT is the variety of vehicles we offer.
That also means fuel recommendations can vary significantly from one vehicle to another.
For example:
- A used Jeep Grand Cherokee with the Pentastar V6 uses different fuel than a Grand Cherokee SRT.
- One Dodge Charger may be perfectly happy on regular gasoline, while another equipped with a high-performance engine recommends premium.
- One Ram 1500 may use regular gasoline, while another with the new Hurricane High Output engine performs best on premium.
- A used FIAT 500L and a FIAT 500 Abarth have different fuel recommendations, even though they’re both FIAT vehicles.
Don’t assume every vehicle from the same manufacturer uses the same fuel. When in doubt, check the owner’s manual, look inside the fuel door or ask one of our product specialists. We’re always happy to help.
Fuel Quality Matters, Too
Regardless of the octane rating, we recommend purchasing fuel from reputable stations that sell Top Tier™ Detergent Gasoline whenever possible. Top Tier gasoline contains enhanced detergent additives that help reduce deposits on fuel injectors, intake valves and combustion chambers, helping modern engines stay cleaner over time. It’s one of the easiest ways to help protect your investment.
In Summary …
- Many Chrysler, Dodge, Jeep, Ram and FIAT vehicles are engineered to run perfectly on regular 87-octane gasoline.
- Some HEMI-powered vehicles perform best on 89-octane mid-grade.
- High-performance vehicles like the Wrangler 392, SRT models, Grand Wagoneer Hurricane, certain Hurricane-powered Ram trucks and several FIAT performance models are designed for premium gasoline.
- Diesel trucks require Ultra Low Sulfur Diesel.
- Electric vehicles don’t require gasoline at all.
The important thing isn’t buying the most expensive fuel. It’s buying the right fuel for the vehicle you’re driving. If you’re ever unsure, stop by Mount Airy Chrysler Dodge Jeep Ram FIAT. Our team will gladly help you identify the correct fuel for your vehicle, explain why it’s recommended and answer any questions you may have. Because getting the most out of your vehicle starts with putting the right fuel in the tank.
