Modern ultra-low-sulfur diesel is hard on a Cummins engine. The refining process that strips out sulfur also strips out lubricity, which leaves your high-pressure injection pump and injectors running drier than they were designed to. A good diesel additive puts that protection back, raises cetane for cleaner ignition, and keeps the fuel system free of the soft deposits that rob power and economy. For 6.7L, 5.9L, and even older 12-valve trucks, the right bottle in the tank is one of the cheapest forms of insurance you can buy for your fuel system.
We focused on the additives that actually matter for a Cummins: lubricity boosters that protect the CP3 and CP4 pumps, detergent packages that clean injectors, cetane improvers for smoother cold starts, and winter anti-gel formulas for cold-weather reliability. Below are seven real, widely available picks ranked best first, each reviewed honestly with its strengths and its weak spots so you can match the bottle to your truck and your climate.
| Photo | Product | Score | Buy |
|---|---|---|---|
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Hot Shot's Secret Diesel Extreme Best Overall Treats: up to 400 gallons per 64 oz bottle | Type: clean and cetane combo |
9.5 | 🛒 Check Price |
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Stanadyne Performance Formula Best for Injection Pumps Treats: ratio about 1 oz per 5 gallons | Type: all-season all-in-one |
9.3 | 🛒 Check Price |
 |
Archoil AR6200 Fuel Treatment Best for Fuel Economy Treats: 1 oz per 10 gallons | Type: combustion and lubricity catalyst |
9.2 | 🛒 Check Price |
 |
Power Service Diesel Kleen +Cetane Boost Best Value Maintenance Treats: ratio about 1 oz per 5 gallons | Type: detergent and cetane (silver bottle) |
9.0 | 🛒 Check Price |
 |
Power Service Diesel Fuel Supplement +Cetane Boost Best Winter Anti-Gel Treats: ratio about 1 oz per 5 gallons | Type: anti-gel winter (white bottle) |
8.8 | 🛒 Check Price |
 |
Lucas Oil Upper Cylinder Lubricant Fuel Treatment Best Lubricity Booster Treats: works for gas and diesel | Type: lubricity and injector lubricant |
8.5 | 🛒 Check Price |
 |
Opti-Lube XPD All Season Diesel Fuel Additive Best All-Season Lubricity Treats: 1 oz per 8 gallons summer dose | Type: top-rated lubricity all-in-one |
8.3 | 🛒 Check Price |
1. Hot Shot's Secret Diesel Extreme: Best Overall
Diesel Extreme is the additive we reach for first when a Cummins needs a real clean rather than just routine maintenance. It pairs an aggressive detergent package with a cetane improver, so it does double duty: it scrubs the carbon and the harder internal diesel injector deposits that cause rough idle and dead miss, while raising cetane enough to smooth out cold starts and ignition. The added lubricity is the part Cummins owners care about most, because it gives the CP3 and the more fragile CP4 pump the film strength that ultra-low-sulfur fuel takes away.
The honest weakness is that this is a concentrated treatment, not an every-fill-up additive. You run it periodically to clean the system, then keep it maintained with a lighter daily product. Because the dose ratio is heavy, a bottle does not cover as many gallons as a maintenance-only formula, so it is best thought of as your deep-clean tool a few times a year rather than something that lives in the tank year round.
- Combines a heavy detergent clean with a cetane boost in one bottle
- Adds lubricity to protect CP3 and CP4 injection pumps
- Removes internal diesel injector deposits (IDID) on stuck injectors
Pros: Strong injector cleaning that owners actually notice in throttle response; One product covers cleaning, cetane, and lubricity; Trusted by a lot of 6.7L Cummins owners for periodic deep cleans
Cons: Designed as a periodic treatment, not a fill-every-tank additive; Heavier dose ratio means a bottle does not stretch as far
2. Stanadyne Performance Formula: Best for Injection Pumps
Stanadyne is one of the few additive makers that also builds diesel injection systems, and that pedigree shows in the Performance Formula. Lubricity is the headline here, which is exactly what a Cummins fuel system wants when running on modern dry ultra-low-sulfur diesel. It also adds a useful cetane bump, includes detergents to keep injectors clean, and carries a water demulsifier that helps separate water so the filter can catch it. As an everyday, every-tank additive, it is one of the most well-rounded options on this list.
Where it falls short is cold weather. The standard Performance Formula is an all-season product, not a hard-core anti-gel, so if you park outside in deep winter you will still want a dedicated winter blend or the Stanadyne winter variant for those months. The detergency is also a slow-and-steady clean rather than a shock treatment, so for a badly gummed-up injector you would pair it with a heavier cleaner first and then maintain with this.
- Made by an injection system manufacturer, so lubricity is the focus
- Restores up to a measurable cetane increase for smoother starts
- All-season formula with detergency and water demulsifier
Pros: Lubricity protection from the company that builds injection systems; Balanced all-in-one you can run every tank; Improves cold start and reduces injector deposits over time
Cons: Not a dedicated winter anti-gel, so very cold climates need a separate product; Detergent action is steady rather than aggressive
3. Archoil AR6200 Fuel Treatment: Best for Fuel Economy
Archoil AR6200 takes a slightly different angle. Instead of leaning hardest on detergency, its strength is combustion efficiency and lubricity. By helping the fuel burn more completely, Cummins owners often see a real bump in mpg, lower exhaust gas temperatures, and fewer DPF regeneration cycles on emissions trucks, which is a meaningful benefit for a 6.7L that spends time towing. The lubricity side is excellent too, giving the injection pump strong protection on dry low-sulfur fuel.
The trade-off is that AR6200 is not the fastest-acting product and it is a premium treatment in value terms. The efficiency and smoothness gains tend to appear over several tanks as combustion stabilizes, so a single bottle will not transform a truck overnight. If you want an instant injector blast for a misbehaving engine, a heavier detergent serves better. For steady long-term efficiency and pump protection, though, this is one of the most respected bottles you can run.
- Improves combustion efficiency for better mpg and fewer regens
- Strong lubricity that protects high-pressure pumps
- Reduces smoke, knock, and exhaust gas temperatures
Pros: Owners frequently report measurable mpg gains on long-haul driving; Excellent pump and injector lubrication; Quieter, smoother running engine and fewer DPF regens
Cons: One of the pricier ways to treat per gallon in qualitative terms; Benefits build over several tanks rather than instantly
4. Power Service Diesel Kleen +Cetane Boost: Best Value Maintenance
The silver bottle of Power Service is one of the most popular maintenance additives among Cummins owners, and for good reason. Diesel Kleen +Cetane Boost delivers a solid cetane bump for smoother, quieter power and easier starts, includes a Slick Diesel detergent to keep injectors and the pump clean, and restores lubricity lost to ultra-low-sulfur fuel. It is sold nearly everywhere, which makes it an easy product to keep stocked and run every fill-up without thinking about it.
The catch is seasonal. The silver Diesel Kleen bottle is the warm-weather formula and does not provide cold-weather anti-gel protection, so in winter you switch to the white-bottle Power Service Diesel Fuel Supplement instead. It is also a maintenance product rather than a deep cleaner, so a heavily deposited injector needs a stronger shock treatment first. As a year-round-minus-winter daily additive that delivers strong value, though, it is hard to beat.
- Cetane boost up to a noticeable increase for smoother power
- Slick Diesel detergent keeps injectors and pumps clean
- Adds lubricity to compensate for low-sulfur fuel
Pros: Widely available at almost any parts store or big-box retailer; Great value for an every-tank maintenance additive; Reliable cetane and detergency that owners trust
Cons: The silver bottle is a warm-weather product, not an anti-gel; Not a deep-clean treatment for badly fouled injectors
5. Power Service Diesel Fuel Supplement +Cetane Boost: Best Winter Anti-Gel
When the temperature drops, the white bottle of Power Service becomes essential gear for a Cummins. Diesel Fuel Supplement +Cetane Boost is built to stop fuel from gelling, lowering the cold filter plugging point so the fuel keeps flowing through your filter on the coldest mornings. Crucially, it can also de-ice a filter that has already started to gel, which can be the difference between a no-start and getting to work. On top of the winter protection it still carries cetane and lubricity, so you are not giving up the daily benefits.
The honest limitation is simply that this is a seasonal product. In summer or in a mild climate it offers no advantage over the standard silver-bottle formula and would be a waste to run year round. The smart move for most Cummins owners is to keep both bottles on the shelf and swap to this white one once nighttime temperatures start dropping below freezing, then return to the warm-weather formula in spring.
- Prevents fuel gelling and lowers the cold filter plugging point
- De-ices frozen fuel filters to restore flow in deep cold
- Adds cetane and lubricity along with anti-gel protection
Pros: Proven anti-gel performance for cold climates; Can de-ice an already gelled filter, not just prevent it; Includes lubricity and cetane, not just winter protection
Cons: Only needed in cold months, so it is a seasonal buy; Overkill for owners in mild or warm climates
6. Lucas Oil Upper Cylinder Lubricant Fuel Treatment: Best Lubricity Booster
Lucas Upper Cylinder Lubricant is a long-standing favorite for one main job: lubricity. Ultra-low-sulfur diesel runs dry, and this treatment puts a protective film back across the injectors, pump, and upper cylinder area where it matters most for pump longevity. Cummins owners often run it specifically to baby a CP3 or to quiet down noisy injectors, and it cleans as it lubricates. It is widely stocked, economical to run, and simple to dose, which makes it an easy maintenance habit.
It is not a do-everything additive, though, and that is the honest caveat. The cetane improvement is modest compared with dedicated cetane boosters, and there is no anti-gel protection, so it will not help you in deep winter on its own. Think of it as a focused lubricity and cleaning supplement that pairs well with a cetane or winter product rather than a single bottle that covers every base. For pump protection at a sensible value, it earns its spot.
- Lubricates and cleans the injectors and upper cylinder
- Neutralizes the low-sulfur fuel lubricity loss
- Works in both diesel and gasoline engines
Pros: Excellent lubricity for protecting injectors and pumps; Very easy to find and economical per treatment; Helps quiet injectors and smooth idle
Cons: Lighter on cetane improvement than dedicated boosters; No anti-gel, so not a winter solution on its own
7. Opti-Lube XPD All Season Diesel Fuel Additive: Best All-Season Lubricity
Opti-Lube XPD has built a reputation among diesel owners largely on the strength of its lubricity, which has scored at or near the top in independent fuel additive wear testing. For a Cummins running a high-pressure injection pump on dry modern fuel, that film protection is exactly what extends pump life. XPD is also a genuine all-in-one, blending detergents to keep injectors clean, a cetane component for smoother running, and cold-weather operability so it can serve across the seasons with the correct dose.
The main downside is availability and dosing discipline. It is more of an enthusiast and online purchase than something you grab at a roadside station, so you need to plan ahead and keep it stocked. The dose ratio also changes between summer and winter, so you have to pay attention rather than pouring a fixed amount. Those minor hassles aside, for owners who prioritize pump protection above all else and do not mind ordering ahead, XPD is one of the most respected bottles in the diesel world.
- Top-tier lubricity score in independent injector wear testing
- All-in-one with detergents, cetane, and cold-weather operability
- Includes a measured pump bottle for easy dosing
Pros: Among the best lubricity ratings of any additive tested; Single all-season bottle covers most needs year round; Strong following among 6.7L and 5.9L Cummins owners
Cons: Not as easy to find on store shelves as mainstream brands; Dosing requires attention to the summer versus winter ratio
Frequently Asked Questions
Do I really need a fuel additive for my Cummins?
For most owners, yes, and the main reason is lubricity. Today’s ultra-low-sulfur diesel has far less natural lubricating ability than the fuel these engines were originally designed around, which leaves your high-pressure injection pump and injectors running drier than ideal. A good additive restores that protection, and many also raise cetane for smoother starts and add detergents to keep injectors clean. Running a quality additive every tank is cheap insurance against expensive fuel system repairs, especially on trucks with the more sensitive CP4 pump.
Which additive is best for protecting the CP4 or CP3 injection pump?
Lubricity is what protects these pumps, so look for products that score high on that specifically. Opti-Lube XPD and Stanadyne Performance Formula are both known for strong lubricity, and Stanadyne carries extra credibility because the company actually builds injection systems. Hot Shot’s Secret Diesel Extreme and Lucas Upper Cylinder Lubricant are also good lubricity choices. For the fragile CP4 pump found in some later 6.7L Cummins trucks, running a high-lubricity additive every single tank is one of the smartest preventive habits you can adopt.
What is cetane and does a higher cetane number help my Cummins?
Cetane measures how readily diesel ignites under compression, similar to how octane works for gasoline but in the opposite direction. A higher cetane number means the fuel ignites faster and more completely, which gives you easier cold starts, quieter and smoother running, and often slightly better throttle response and economy. Additives like Power Service Diesel Kleen and Hot Shot’s Secret Diesel Extreme include cetane improvers. The gains are real but modest, so do not expect a dramatic power jump, just a cleaner and smoother running engine.
What additive should I use in winter to stop my Cummins from gelling?
In cold weather you need a dedicated anti-gel product, not just a maintenance additive. The Power Service Diesel Fuel Supplement in the white bottle is the go-to choice because it lowers the cold filter plugging point and can even de-ice a filter that has already started to gel. Many summer-formula additives, including the silver Power Service bottle, offer no meaningful anti-gel protection, so swap products as the seasons change. Keep a winter bottle on hand once nighttime temperatures start dropping below freezing.
Can I mix two different diesel additives in the same tank?
Often yes, but do it thoughtfully. A common and effective combination is pairing a focused lubricity product like Lucas Upper Cylinder Lubricant with a separate cetane or detergent additive, since they target different jobs. What you should avoid is doubling up on similar all-in-one products, which can over-treat the fuel and waste money without added benefit. The cleaner approach is to pick one all-in-one for daily use, then add a dedicated cleaner or anti-gel only when you specifically need that function.
Our Verdict
For most Cummins owners, Hot Shot’s Secret Diesel Extreme is our top pick because it does the most in one bottle, cleaning injectors, boosting cetane, and protecting the pump with added lubricity, making it the ideal periodic deep clean for any 5.9L or 6.7L. Our runner up is the Stanadyne Performance Formula, the best every-tank choice thanks to its injection-system pedigree and excellent all-around lubricity. Pair a deep cleaner like Diesel Extreme a few times a year with a daily maintenance additive, and swap to a white-bottle anti-gel in winter, and your Cummins fuel system will stay healthy for the long haul.
