Harley-Davidson Fuel Tank Capacity: More Gallons Equals More Miles

For many ‘newbies’, owning their first Harley is a dream come true!

A common query about the super popular Harley-Davidson is in relation to the legendary motorcycle’s fuel tank capacity.

If you ask me, it’s a good thing to check the fuel tank capacity of any motorcycle before you buy it. The reason is, the range of your motorcycle will depend on how much juice it can carry.

And once you choose a particular fuel tank size, there’s no going back. So, for hardcore, long-distance riders, fuel tank size matters.

Like all other motorcycles, a Harley Davidson’s fuel tank capacity depends on the model and the corresponding engine size. Generally, it varies between 3 to 6 gallons.

Want to find out more about the fuel tank capacity of Harley motorcycles?

You are in the right spot. Let’s start.

How many gallons does a Harley Davidson hold?

Honestly, this is something that I find odd.

Manufacturers will keep going on about various factors like torque, load capacity, the performance of high-end motorcycle tires, and more. But the fuel tank capacity remains as ignored as the piece of white crayon.

Still, for day-to-day commuters, the tank size and fuel consumption rate can make or break the decision to choose a bike.

To start with, let’s take a look at 10 of the best-selling models from Harley, and their fuel tank capacities.

Harley Davidson Motorcycles	Fuel tank capacity in gallons
Street Glide Special	6
Road Glide Special	6
Tri Glide Ultra	6
Iron 883	3.3
Iron 1200	3.3
Low Rider S	5
Road King	6
Electra Glide	6
Sportster S	3.1
Pan America 1250	5.6

Look closely at the specs and you’ll notice that the fuel tank capacity is related to the engine size.

Obviously, motorcycles with a larger engine size will consume more fuel. That will require a fuel tank of a higher capacity.

For example, the Harley 883 has an engine size of 883 ccs and a tank capacity of 3.3 gallons. 

On the other hand, the Street Glide Special comes with a whooping 1868cc of engine displacement. To feed this hungry beast, a fuel tank size of 6 gallons is needed.

So, the distance they will travel on a full tank isn’t the same.

In case you’re wondering what cc means, it’s the Cubic Capacity of the motorcycle engine. It’s the available space inside the engine chamber where the combustion of the air-fuel mixture takes place. The larger it is, the more powerful the bike is.

And another thing.

Some older Harley motorcycles come with a reserve tank that serves as a backup when the fuel in the main tank runs low.

Note, the reserve tank isn’t a separate fuel tank. It’s a part of the main fuel tank with a capacity of around 10-15% of the total fuel tank volume.

In normal riding conditions, the fuel in the reserve tank is stopped from flowing out by a fuel valve that acts as a barricade. 

It’s operated by a flip switch in three positions. This switch is usually located below the fuel tank or the seat.

During normal riding conditions, the switch remains in the “ON” position. Once you switch the reserve fuel switch to the “RES” position, this valve barricade is removed and the fuel stops flowing.

That gives you some additional time to find a gas station before the bike runs dry.

However, this is mostly found in older models with a carbureted engine. Modern Harley motorcycles with a fuel injection system will not have a reserve tank. In that case, there will be no control switch, nor any mention of the reserve tank in the user manual.

 If the motorcycle doesn’t have a reserve tank, it’s not a cause for concern. These motorcycles will have a low-fuel indicator light.

In case your motorcycle has a reserve fuel tank, you need to use it occasionally. This ensures that the fuel in the tank doesn’t get spoiled.

How Much Distance Can a Harley Motorcycle Go on a Full Tank of Gas?

Let’s face it. Finding exact information on a motorcycle’s fuel efficiency is difficult. 

And let me tell you, the engine specs in ccs, don’t give you the complete picture either.

In other words, you’ll need to do your own calculations to find the mpg of your motorcycle. It can be calculated by using a simple formula.

Miles ridden / gallons used = mpg.

Let’s assume that you have ridden for 150 miles and used up to 3 gallons of gas. 

150 miles / 3 gallons of fuel = 50 mpg.

So hypothetically, your motorcycle will run 50 miles per gallon of fuel.

In theory, if you have a 6-gallon tank, you’ll be able to cover 300 miles on a full tank of gas. 

Harley motorcycles usually deliver 30-45 MPG in the city and around 40-60 MPG on highways. Compared to the products from brands like Honda and Yamaha, these are relatively lower numbers.

The reason for this is the big V-twin engines with a relatively heavier structure.

(Not to forget looking that good comes at a cost)

While this will not be the exact figure, it gives you an idea about the fuel efficiency of your motorcycle. Knowing this will also help you to calculate the fuel cost for a trip.

But how many miles a full fuel tank will allow you to ride can change depending on various other factors. Take a look.

• The type of the engine and its fuel consumption rate plays an important role in the mpg numbers of any motorcycle. 
• If you prefer to ride your bike like Johnny Blaze, your mpg will drop. The higher the RPMs, the lower the mpg is. Additionally, the proportion of idle time while on road can also increase the fuel consumption rate. In fact, this also depends on complex factors like the overall aerodynamics of the motorcycle.
• The type of terrain you’re driving on also influences fuel consumption. Mileage will drop while driving on roads that demand a lower speed. Factors like the slope of the road and its bumpiness will also play a role.
• The more weight you’re carrying on the bike, the higher the fuel consumption rate. So, pack for long trips wisely.
• When the temperature drops, so does the mileage. Riding in warm conditions will make the fuel in the tank last longer.
• If the motorcycle isn’t well maintained the mileage will be affected. Factors like under-inflated tires, clogged filters etc. are some of the main reasons behind that.
• Lastly, if you have modified the air-fuel mixture to produce a rich mixture, the fuel economy will come down.

My point is this…

For frequent long-distance riders, a small fuel tank is as bad as pineapple toppings on a pizza – sorry, pineapple-on-pizza lovers! So, make sure that you pick the right model.

Frequently Asked Questions

How many gallons does a Harley Davidson hold?

The capacity of a Harley Davidson motorcycle’s fuel tank capacity in gallons depends on the engine size. The higher the engine size, the larger the tank capacity. Generally, this varies between 3 to 6 gallons.

What is the Harley Sportster gas tank size?

The Harley Sportster comes with a 3.1-gallon fuel tank.

Which bike has the highest fuel tank capacity?

The BMW K1600GT with a 7-gallon tank is one of the toppers in the market. The Honda CRF1100L Africa Twin Adventure Sports has a 6.47-gallon tank capacity which is another motorcycle with a high fuel tank capacity.