Frequently Asked Questions

Diesel Fuel Additives

What Additive should I use?

For most customers, our most common recommendation is XPD All-Season. It is our most popular diesel fuel additive because it covers the most common fuel concerns in one product, including lubricity, injector cleanliness, water separation, corrosion protection, fuel stability, cetane improvement, and cold-weather support.

Customers in warmer states often use XPD All-Season year-round for the lubricity, cleaning, water control, and performance benefits, even when anti-gel protection is not needed.

For customers with a more specific need, another Opti-Lube product may be a better fit. For example, XL Extreme Lubricant is best when maximum lubricity is the main goal, Boost! is best when cetane improvement is the main goal, Winter is best for severe cold-weather anti-gel protection, and Single Clean is best for a stronger one-time cleaning treatment.

What is the shelf life of the product?

Unopened product stored in good conditions can last up to about 5 years. After opening, we suggest using the product within 1–2 years for best results.

Shelf life depends on storage conditions, including temperature, sunlight, humidity, how tightly the container is sealed, and how much product remains in the container. Store sealed, upright, and out of direct sunlight when possible.

Do your additives void my warranty?

No. Opti-Lube fuel additives are compatible with all makes, models, and equipment when used as directed. They are safe for fuel systems and emissions equipment, including diesel particulate filters (DPFs), when used properly.

What types of engines can it be used in?

Virtually any diesel engine. All diesel engines benefit from the features in Opti-Lube Diesel Fuel Additives, including those with the latest emissions equipment and the oldest diesels out there.

What is the treatment rate? How much do I use?

Treatment rates vary by product, so always follow the directions on the bottle or product page.

For quick reference, XPD All-Season is commonly used at 1/4 oz per gallon of diesel fuel. That means:

5 gallons of fuel = 1.25 oz
10 gallons of fuel = 2.5 oz
20 gallons of fuel = 5 oz
32 gallons of fuel = 8 oz

Using a little more or less than the recommended amount usually is not a problem, but the best value and performance normally comes from staying within the recommended treatment range.

Can Opti-Lube be used with biodiesel or renewable diesel?

Yes. Opti-Lube diesel additives are compatible with commercially available diesel fuels, including ULSD, biodiesel blends up to B20, and renewable diesel such as R99. These fuels can still benefit from added lubricity, cleaning, corrosion protection, water separation, and fuel stability.

Can Opti-Lube be used with kerosene?

Yes. Opti-Lube diesel additives can be used with diesel fuel that has been blended with kerosene. Kerosene can reduce lubricity, so adding a lubricity-focused additive such as XL Extreme Lubricant or XPD All-Season can be helpful.

Do Opti-Lube diesel fuel additives contain harmful alcohol, Teflon/PTFE, or solid particles?

No. Opti-Lube diesel fuel additives do not contain harmful alcohols, Teflon/PTFE, solid particles, or anything designed to remain suspended in the fuel that could harm the fuel system.

Some fuel additive ingredients may be alcohol-based for performance reasons, but Opti-Lube diesel additives do not contain harmful alcohols such as methanol or ethanol.

What is Cetane, and why boost it?

Cetane relates to how readily diesel fuel ignites during combustion. A higher cetane number can help improve cold starts, reduce ignition delay, smooth engine operation, and support more efficient combustion.

Diesel fuel quality can vary by supplier, region, and season. Winter-blended fuel and some lower-cetane fuels may leave certain engines feeling rougher, louder, harder to start, or less responsive. A cetane-improving additive can help offset those issues.

Can I mix Opti-Lube Diesel Additives?

Yes. Our diesel additives are completely compatible with each other. Though Opti-Lube's diesel additives were designed to be used alone, when attempting to pinpoint a specific benefit or cetane increase, mixing the products can be beneficial. For example, we have many customers that have found mixing XL with Boost! has yielded great results.

How should I add the product to my fuel?

Add the recommended amount directly to the fuel tank, preferably before or during fueling. Filling the tank afterward helps disperse the additive, but no special mixing is required. Normal driving and fuel movement in the tank will finish blending the product into the fuel.

Does it do anything besides reduce wear and friction?

Yes.

These are multi-functional additives; each product helps improve water separation, prevent corrosion, extend fuel storage life, and clean injectors. Depending on the product, they boost cetane and contain anti-gel additives. Many customers report improved fuel economy, but results vary depending on fuel quality, vehicle condition, driving habits, and operating conditions.

Can I mix Opti-Lube with a competitor's product?

Generally, yes, but we do not recommend it. Some additives on the market can reduce lubricity or handle moisture differently than recommended by engine manufacturers. For best results, use Opti-Lube products as directed.

What is the difference between XPD All-Season, XL Extreme Lubricant, Summer+, Boost!, and Winter?

XPD All-Season is the best all-around choice for most diesel owners. It provides lubricity, injector cleaning, water separation, corrosion protection, fuel stability, a cetane boost, and cold-weather support.

XL Extreme Lubricant is the best choice when maximum lubricity is the main goal.

Summer+ is a warm-weather formula focused on cetane, lubricity, detergency, and fuel economy.

Boost! is primarily for customers who want a stronger cetane increase.

Winter is best for cold-weather anti-gel protection and should be used before the fuel gels.

Single Clean is a stronger cleaning treatment used when injector deposits, smoke, rough running, or fuel system cleanliness are the main concern.

Should I use XPD All-Season if I do not need anti-gel protection?

Yes. XPD All-Season is not just an anti-gel product. In warm climates, customers still use it for lubricity, injector cleanliness, water separation, corrosion protection, fuel stability, and overall fuel quality. The anti-gel portion simply adds extra protection if temperatures drop.

Should I use XL Extreme Lubricant or XPD All-Season?

Use XPD All-Season if you want the best all-around additive with lubricity, cleaning, cetane, water separation, corrosion protection, stability, and cold-weather support.

Use XL Extreme Lubricant if your main goal is the highest lubricity improvement and you do not need anti-gel protection. XL is a great choice for warm climates, older diesel engines, equipment, or customers who want to focus mainly on reducing fuel system wear.

Can I use more than the recommended amount?

A small amount over the recommended dose usually is not a concern. However, using significantly more than recommended normally does not provide extra benefit and may not be cost-effective. For most situations, stay within the recommended treatment range listed on the bottle or product page.

For cleaning concerns, it is usually better to use the correct cleaner, such as Single Clean, rather than heavily overdosing a maintenance additive.

Do I use Single Clean instead of my regular additive?

Single Clean can be used as a stronger cleaning treatment when needed. It is commonly used when a customer wants to address injector deposits, smoke, rough running, or fuel system cleanliness. After using Single Clean, most customers return to their regular maintenance additive such as XPD All-Season, XL Extreme Lubricant, or Summer+.

Are Opti-Lube diesel additives compatible with ULSD, DPF, DEF, EGR, and modern emissions systems?

Yes. Opti-Lube diesel fuel additives contain no sulfur and are compatible with modern diesel fuel systems and emissions equipment when used as directed, including vehicles equipped with DPF, DEF, EGR, and SCR systems.

Some customers report cleaner operation or less frequent regeneration, but results vary depending on fuel quality, engine condition, driving habits, and operating conditions.

Will a 2-micron fuel filter remove the additive?

No. Opti-Lube fuel additives dissolve into the diesel fuel. They are not solid particles, so a normal fuel filter, including fine filtration systems, will not filter the additive out of the fuel.

My additive looks cloudy or has white particles. Is it still okay to use?

In some conditions, especially after exposure to cold temperatures, certain components may temporarily crystallize or make the product look cloudy. This does not mean the product is bad.

Warm the sealed bottle in a warm water bath, around 90–110°F, for 20–30 minutes, then shake well. Once the product returns to normal appearance, it can be used as directed.

How should I store Opti-Lube additives?

Store additives sealed, upright, and out of direct sunlight when possible. A cool, dry location is ideal, but normal garage storage is usually fine. Avoid long-term exposure to extreme heat, freezing temperatures, or direct sunlight.

If the product has been exposed to cold and appears cloudy or has crystals, warm it gently and shake before use.

When should I add anti-gel?

Anti-gel additives should be added before the fuel reaches its cloud point or begins to gel. They are preventative products, not emergency thawing products.

For best results, add the product before or during fueling so it can fully mix with the fuel. If the fuel is already gelled, use an emergency product such as Gel Melt and follow the label directions.

Can Opti-Lube help with black smoke or rough running?

It may help if the issue is related to fuel quality, cetane, or injector deposits. Single Clean is the best choice for a stronger cleaning treatment, while XPD All-Season, XL Extreme Lubricant, and Summer+ are better suited for regular maintenance. If the issue is mechanical, tuning-related, air-related, or emissions-system related, an additive may not correct the problem.

Gasoline Additives

Does your Additives void my warranty?

No, our fuel additives are completely compatible with all makes, models and equipment. No damage will be caused to your fuel system or emissions equipment, including if using the product correctly.

What types of engines can it be used in?

Virtually any gasoline engine. All gasoline engines benefit from the features in Opti-Lube's Gas Additives, including large and small engines. We use it in our lawn mower and ATV's all the time.

What is the treatment rate? How much do I use?

This varies by product, please see individual treatment rates on each product listing or on the bottles themselves.

How should I add the product to my fuel?

Does Gas Enhance contain PEA?

No. Gas Enhance does not contain PEA. It uses a PIBA-based detergent package designed for regular use to help keep gasoline fuel systems clean.