Harley Davidson Recommended Fuel: Worth Pumpin’ Premium?

Last Updated on September 19, 2023 by Chase Manhattan

The type of fuel you use in your Harley Davidson can significantly impact its performance, lifespan, and overall running issues.

This article delves into the Harley Davidson recommended fuel, the implications of deviating from these specifications, and the potential running issues that could arise.

Chase Manhattan

What’s The Harley Davidson Recommended Fuel? (Just Use Premium)

Harley-Davidson motorcycles are known for their high-performance engines. As such, they require fuel that can withstand high compression without premature detonation. Harley-Davidson recommends premium unleaded gasoline for all its fuel-injected models.

But why premium fuel? Premium fuel has a higher octane rating, often between 91-95, making it more resistant to pre-ignition caused by the high compression in Harley’s V-Twin engines.

This resistance to premature combustion is due to octane’s high compression tolerance. The more octane in gasoline, the better it withstands combustion, allowing the spark plugs to ignite the fuel mixture at precisely the right time for optimum efficiency.

What Happens If You Don’t Use Premium?

If you opt for regular fuel, you might be compromising your motorcycle’s performance and engine health. The lower octane content in regular fuel means it is more prone to premature ignition when subjected to the high compression in Harley’s engines. This premature ignition, also known as pre-detonation or knocking, happens when the air-fuel mixture in the engine starts to burn before the spark from the spark plug ignites it.

Potential Running Issues

If your Harley Davidson is not running smoothly, it could be due to several reasons, including improper fuel usage. Here are some potential running issues that might occur:

1. Sputtering When Accelerating (misfiring)

If your Harley Davidson is running on a lower-grade fuel, it might sputter when accelerating. This issue is usually due to misfiring, where the fuel-air mixture in the engine cylinders does not ignite correctly or at the right time. Misfiring can cause the engine to run unevenly, leading to sputtering or jerking during acceleration.

2. Abnormal Idle (High or Low)

Another symptom of using inadequate fuel in your Harley Davidson is abnormal idling. If the fuel’s octane rating is too low for your motorcycle’s high compression engine, it can lead to pre-detonation or knocking, causing the engine to idle high or low.

3. Difficulty Starting

Lastly, starting issues can also arise from using the wrong fuel. If the fuel cannot withstand the compression in the engine, it may ignite prematurely, leading to difficulty starting your bike.

Can You Get Away with 87 Octane In A Pinch?

The key to remember here is that the octane rating is not a measure of the fuel’s quality or power, but rather its resistance to ignition under compression. Therefore, using 87 octane fuel in your Harley Davidson in an emergency shouldn’t cause immediate damage.

However, depending on your motorcycle’s engine and its compression ratio, it might not perform optimally and could cause long-term damage if used regularly.

What Are The Benefits of Premium Gas?

Apart from preventing premature combustion, premium fuel offers other benefits to your motorcycle. It generally contains more additives that can help keep your engine clean by preventing the buildup of dirt and deposits.

Otherwise, premium fuel can potentially deliver slight gains in performance and fuel economy, although these improvements are often too small to justify the higher cost of premium fuel.

Are There Downsides to Premium? (Besides Cost)

While premium fuel is beneficial for high-performance engines like those in Harley Davidson motorcycles, it does come with a couple of downsides.

The most obvious one is the cost – premium fuel is significantly more expensive than regular fuel. If your motorcycle doesn’t require premium fuel, using it would only result in unnecessary spending.

FAQs and Related Questions

Do Harleys use premium gas?

Yes, Harley-Davidson recommends using premium gas in their motorcycles due to the high compression of their engines.

Can I run 87 octane in a Harley Davidson?

While you can use 87 octane in an emergency, it’s not recommended for regular use in Harley Davidson motorcycles. The lower octane rating means it’s more prone to pre-ignition, which can damage the engine over time.

Should I run premium gas in my Harley Davidson? Why?

Yes, it’s advisable to run premium gas in your Harley Davidson. Premium gas has a higher octane rating, making it more resistant to pre-ignition. This resistance ensures that the fuel-air mixture in the engine ignites at the right time, improving efficiency and performance and reducing the risk of engine damage.


In conclusion, while the decision to use premium fuel in your Harley Davidson might seem like an unnecessary expense, it’s a small price to pay for the health and performance of your motorcycle. With the right fuel, your Harley Davidson will perform optimally, run smoothly, and last longer.

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