The Differences Between #1 Diesel and #2 Diesel

Pull up to the pump and you might see options for #1 and #2 Diesel. But beyond the number, what’s the difference? We’ll help you see what the differences are so you can decide which one is best for you.

We’ll look at characteristics like volatility, viscosity, Cetane rating, cost and availability to help you choose the right fuel for your vehicle and driving needs.

The Difference in Diesel Fuels

Let’s take a look at the main differences between these two fuels. As you’ll see, some key points give each type distinct advantages and disadvantages.

1. Volatility

#1 Diesel has higher levels of a compound known as cetane. This makes it more volatile than #2. Higher volatility translates to a faster and more fuel-efficient start. However, lower volatility means a slower burn while driving which means better fuel efficiency while you’re on the road.

2. Viscosity

Like all liquids, diesel fuel can be measured by its viscosity or thickness. This is especially important to consider in the winter as Diesel can become thicker as the temperature drops.

#1 Diesel has a lower viscosity which means it’s thinner than #2 Diesel. So, in the winter months, #1 Diesel will work better in engines because it won’t end up too thick.

On the other hand, in hot weather, #1 Diesel may become too thin which can also be a problem for engines. In that case, #2 Diesel may work better because it will maintain some of its viscosity.

3. Cetane Rating

The cetane rating for diesel fuel is a measurement of ignition quality. It determines how quickly the fuel ignites when it is compressed in the cylinder. The rating is important because the higher the rating the cleaner and more complete the burn is.

With a higher rating, your truck will get better fuel economy, run smoother and produce less noise. A perfect cetane rating is 100.

There isn’t a certain mandated cetane rating for diesel fuels #1 Diesel falls between 45 and 50, resulting in better ignition quality. #2 Diesel typically rates between 40 and 45.

4. Cost

Typically you’ll find that #2 Diesel is cheaper than #1. The reason for this is that #2 requires less refining to be made so it costs less for the fuel suppliers.

#1 Diesel includes additives like anti-gelling agents which help increase performance in cold weather. The additives add to the cost of the fuel.

#2 Diesel is more popular than #1 Diesel. Since it is more commonly used because of its lower cost, surprisingly this high demand actually lowers the price as opposed to #1 Diesel which caters to a more specific niche market.

#1 Diesel is considered by many a premium fuel and its cost reflects that. As you’ll see, there are several reasons you may choose to invest in this higher-grade of diesel fuel.

With lubricants, help keep your fuel diesel system running smoothly, #1 Diesel produces less friction in the fuel pump and other engine parts, and you’ll extend the life of your engine.

Over time, diesel fuel systems can get dirty due to sediments and other debris. #1 Diesel contains fuel additives that can help clean your system as you drive.

This is another way that #1 Diesel can extend your vehicle’s life. It can also improve fuel efficiency since your engine doesn’t have to work as hard to get around the gunk.

Availability

#2 Diesel is the most commonly available in all gas stations. It’s also the most used one among diesel truck owners. Why is that? As we stated above, #2 Diesel is less volatile than #1. That means the fuel doesn’t burn as quickly.

This is why #2 Diesel is more fuel efficient than #1 Diesel, making it ideal for long trips and highway driving. Another reason for its popularity, and in turn, its higher availability, is that #2 Diesel is less expensive than #1.

A word of advice, if you’re using #2 Diesel, you’ll want to use fuel additives to ensure excellent fuel efficiency and longer engine life.

Should I Use #1 Diesel or #2 Diesel?

If you meet the criteria below, you should use #1 Diesel:

1. You drive in a cold climate: #1 Diesel has a lower cloud point and a lower pour point which means it flows better when it’s colder outside. This is very important in cold weather because it prevents “gelling”. Gelling is when the fuel gets tick and clogs the fuel filter. Obviously, this will make your engine run poorly or not at all. If you must use #1 use an anti-gelling fuel additive during the winter

1. You want better fuel efficiency: Even though #1 Diesel costs more, the higher cetane rating makes the engine have a more efficient combustion. This could produce better MPG which could offset the higher cost.

1. You have a high-performance engine: If you would consider your diesel engine “performance-oriented” you would want #1 Diesel due to the improved ignition quality you’ll get from the higher cetane rating. Benefits include increased power, a smoother operation and possibly a reduction in emissions.

1. You want your engine to last forever: OK, maybe not forever but typically engines that consume #1 Diesel last longer than those that do not. The additional additives like lubricants and detergents help reduce wear and tear on the engine parts. This could lead to a longer-lasting engine and less money spent on maintenance and repairs.

1. You haul heavy loads: You can check with your fuel supplier’s information board but some #1 Diesel formulas include additives that are designed for heavy-duty use. These additives protect your engine if you frequently use your truck for hauling heavy loads such as towing a large trailer or a 5th wheel.

If you meet the criteria below, you should use #2 Diesel:

1. You live where you rarely see snow: If you live in an area that barely ever gets below 32 degrees Fahrenheit and/or your winters are pretty mild, #2 Diesel is the way to go. The lower cloud point isn’t as crucial and your engine will run just fine in mild conditions.

1. You are budget-minded: #2 Diesel is a more affordable option. If your main concern is how much it’s going to cost to fill up your tank with enough fuel to get you to your next paycheck, go with #2 Diesel.

1. You like convenience: #2 Diesel is more readily available when you pull up to the pump. Especially if you live in remote areas, you’re more likely to find #2 Diesel at most gas stations. So if you don’t want to travel several miles to fill up, this is the choice for you.

1. You drive an old truck: Older trucks are not as sensitive to things like Cetane ratings compared to the sensitive, brand-new truck you just drove off the Dealer’s lot. Your old truck will handle #2 Diesel and keep churning out the miles without much trouble.

When it comes to deciding between #1 and #2 Diesel, it should be based on your individual needs, circumstances and priorities. Considering your budget, the way you drive, where you live and what type of vehicle you have, an informed decision should be easy.

Weigh the various factors like cost, fuel mileage, performance and climate and choose the best option that suits your needs. When you choose the most appropriate fuel, you’re well on your way to a long-lived partnership with your favorite truck.

If that truck needs performance upgrades or replacement parts keep us in mind. ProSource Diesel is the best source for diesel truck parts and accessories.