The 6.7L Power Stroke is a strong engine, but its Bosch CP4.2 high pressure fuel pump is famously sensitive to poor lubricity in modern ultra low sulfur diesel. A good additive is cheap insurance for that pump, and it also bumps cetane for cleaner starts, separates out water before it reaches your injectors, and keeps fuel flowing when the temperature drops below freezing. The wrong additive, or none at all, can leave you with rough idle, hard cold starts, and in the worst case a CP4 failure that contaminates the entire fuel system.
We focused on what actually matters for a 6.7 Power Stroke owner: real lubricity protection for the CP4, honest cetane gains, water demulsification or absorption, injector cleaning, and reliable anti-gel performance for winter drivers. Below are the seven additives we trust most, ranked best first, with an honest look at where each one falls short.
| Photo | Product | Score | Buy |
|---|---|---|---|
 |
Hot Shot's Secret Diesel Extreme Best Overall Cetane booster plus injector cleaner plus lubricity, dual concentration treat rate |
9.5 | 🛒 Check Price |
 |
Stanadyne Performance Formula Diesel Fuel Additive Best for CP4 Protection Made by a fuel system manufacturer, all season lubricity, cetane, and detergency |
9.3 | 🛒 Check Price |
 |
Archoil AR6200 Fuel Treatment Best Lubricity Concentrated lubricity and combustion catalyst, treats large fuel volume per bottle |
9.1 | 🛒 Check Price |
 |
Power Service Diesel Kleen Plus Cetane Boost Best Value Summer cetane and detergent additive, widely stocked, silver bottle |
8.9 | 🛒 Check Price |
 |
Power Service Diesel Fuel Supplement Plus Cetane Boost (White Bottle) Best Anti-Gel Winter anti-gel and cold flow improver, protects to deep sub freezing temps |
8.7 | 🛒 Check Price |
 |
Lucas Oil Upper Cylinder Lubricant and Injector Cleaner Most All-around Upper cylinder lubricant and injector cleaner, works in diesel and gas fuel |
8.4 | 🛒 Check Price |
 |
Opti-Lube XPD All-Season Diesel Fuel Additive Best All-Season Lubricity All season formula, top tier lubricity score, with cetane and detergents |
8.2 | 🛒 Check Price |
1. Hot Shot's Secret Diesel Extreme: Best Overall
Diesel Extreme is the additive we reach for first on a 6.7 Power Stroke because it does the three jobs that matter most in one bottle. It lifts cetane for noticeably easier cold starts and a quieter idle, it carries a genuine detergent package that scrubs deposits off the injector tips, and it adds the lubricity the CP4.2 pump desperately needs from today’s dry low sulfur fuel. Owners who run it as a periodic clean out frequently report the truck pulling stronger and idling smoother within a tank or two, which lines up with what we saw.
The honest weakness is that it is built as a performance and cleaning additive, not a winter product. It has no meaningful anti-gel or cold flow improver, so if you live where diesel waxes up you will still need a dedicated anti-gel alongside it. It is also at its best when you run the heavier clean out concentration first, which uses more product, before settling into the lighter maintenance dose. Treat it as your cetane and CP4 protection workhorse and pair it with a cold weather additive in the winter months.
- Raises cetane up to seven points for smoother, quicker starts
- Cleans coked injectors and removes internal diesel injector deposits
- Adds lubricity to protect the CP4 pump from dry ULSD fuel
Pros: All in one cetane, cleaning, and lubricity package; Strong reputation among 6.7 Power Stroke owners for restoring lost power; Concentrated, so a little treats a full truck tank
Cons: Not an anti-gel, so winter drivers still need a separate cold flow product; Strongest results come from the more aggressive clean out dose, not just maintenance
2. Stanadyne Performance Formula Diesel Fuel Additive: Best for CP4 Protection
Stanadyne carries unique credibility because the company designs and builds diesel fuel injection systems, so when they formulate an additive for lubricity and injector health it is coming from people who understand the hardware on your 6.7 Power Stroke. The Performance Formula is a sensible all season choice that improves lubricity to protect the CP4 pump, keeps injectors clean, demulsifies water, and adds a light cetane lift. It is the additive we recommend to an owner who wants steady, low drama protection rather than a dramatic clean out.
The trade off is that this balance means nothing is maxed out. The cetane gain is real but modest, the detergent action is gentle rather than aggressive, and the winter cold flow protection is fine but not class leading in deep cold. If your truck already runs well and you simply want a manufacturer backed shield for the fuel system, this is excellent. If you are chasing a noticeable power and idle improvement from a heavily carboned engine, a more aggressive cleaner will move the needle faster.
- Comes from a company that actually builds diesel fuel injection systems
- Improves lubricity to guard the high pressure pump and injectors
- Cleans injectors and adds a modest cetane and water demulsifier package
Pros: Engineered by a fuel injection equipment maker, not just a chemical blender; Balanced all in one formula safe for everyday use; Trusted across many diesel platforms, not only the Power Stroke
Cons: Cetane and cleaning punch is gentler than a dedicated performance additive; Winter anti-gel performance is only adequate, not the strongest in this list
3. Archoil AR6200 Fuel Treatment: Best Lubricity
If your single biggest worry on a 6.7 Power Stroke is the CP4.2 pump, Archoil AR6200 is one of the strongest lubricity plays you can run. It is built around boundary lubricity and combustion improvement, so it pads the wear surfaces inside the pump and injectors while helping the fuel burn more completely. Owners commonly report less smoke, smoother running, and in some cases fewer regen cycles. Because it is so concentrated, a small dose treats a lot of fuel, which makes it easy to run continuously as protection.
What it does not pretend to be is a winter additive or a deep detergent flush. There is essentially no anti-gel capability, so cold climate drivers must pair it with a dedicated cold flow product. It also will not blast years of injector coking out the way a strong cleaner can, since its mission is protection and combustion, not aggressive cleaning. Use it as your everyday lubricity and efficiency layer, and bring in a cleaner or anti-gel as the situation demands.
- Adds strong lubricity to reduce wear on the CP4 and injectors
- Improves combustion efficiency for cleaner burn and reduced smoke
- Highly concentrated so one bottle treats a large amount of fuel
Pros: Excellent lubricity protection, a priority on the CP4 equipped 6.7; Helps reduce regen frequency and smoke for some owners; Very economical per gallon treated thanks to concentration
Cons: Little to no anti-gel, so winter drivers need a separate product; Not primarily a heavy injector clean out additive
4. Power Service Diesel Kleen Plus Cetane Boost: Best Value
Power Service Diesel Kleen in the silver bottle is the additive most 6.7 Power Stroke owners can find on any store shelf, and it earns its place as our value pick. It bumps cetane for better starts, runs a detergent package that keeps injectors clean, and includes Slickdiesel lubricity to help protect the high pressure pump. For an owner who wants a dependable every tank maintenance additive without overthinking it, this is a genuinely sound, easy to source choice.
The catch to remember is that the silver Diesel Kleen is the warm weather formula and has no anti-gel protection, so it is the wrong bottle to lean on in winter. For that, Power Service sells the white Diesel Fuel Supplement, and confusing the two leaves you exposed when temperatures crash. As an all around performer it is also a step behind the most aggressive cleaners and cetane boosters, but for routine upkeep at a friendly value it is hard to argue with.
- Boosts cetane for easier starting and smoother idle
- Detergent package keeps injectors and the fuel system clean
- Adds slickdiesel lubricity to protect pump and injector wear surfaces
Pros: Available almost everywhere, easy to restock on the road; Good blend of cetane, cleaning, and lubricity for routine use; Strong value for how much fuel each bottle treats
Cons: This silver bottle version is a summer formula, not an anti-gel; Cetane and cleaning are solid but not the most powerful here
5. Power Service Diesel Fuel Supplement Plus Cetane Boost (White Bottle): Best Anti-Gel
When winter sets in, the white bottle Power Service Diesel Fuel Supplement is the anti-gel we trust on a 6.7 Power Stroke. It lowers the cold filter plugging point so wax crystals do not clog your fuel filter, includes an anti-icer that disperses water to prevent fuel line freeze up, and still carries cetane and lubricity so you are not sacrificing protection to get cold flow performance. For drivers in genuinely cold regions, this bottle is the difference between starting on a frigid morning and being stranded.
The honest limitation is that it is a seasonal tool. In summer it is more than you need, and it is best rotated in only when temperatures threaten to drop. It also has to go in before the fuel gels, because no additive reliably reverses fuel that has already turned to wax in the lines and filter. Add it preventively as the cold arrives and keep a bottle in the truck, and it earns its anti-gel crown.
- Prevents fuel gelling and lowers the cold filter plugging point
- Anti-icer disperses water to stop fuel line freeze up
- Adds cetane and lubricity while protecting against cold weather
Pros: Excellent winter protection for cold climate Power Stroke drivers; Combines anti-gel with cetane and lubricity in one bottle; Easy to find and trusted by diesel owners for decades
Cons: A winter specific product, overkill in warm summer months; Must be added before fuel actually gels, not as a thaw fix
6. Lucas Oil Upper Cylinder Lubricant and Injector Cleaner: Most Multi-purpose
Lucas Upper Cylinder Lubricant is the jack of all trades in this group, and that flexibility is exactly why owners like it. It lubricates injectors, the pump, and upper cylinder surfaces, helps offset the dryness of ultra low sulfur diesel, and works in gasoline engines too, so one bottle can serve a whole driveway of vehicles. On a 6.7 Power Stroke it gives you an easy, inexpensive lubricity layer to help protect the fuel system between heavier treatments.
Because it is a generalist, it does not specialize in the things a 6.7 owner often cares about most. There is no meaningful cetane boost and no anti-gel, and while it adds lubricity, it is not marketed or formulated specifically around CP4.2 protection the way the dedicated diesel additives above are. Think of it as a handy, budget friendly supplement and household multitool rather than your primary line of defense for the high pressure pump.
- Lubricates injectors, pumps, and upper cylinder areas
- Cleans and lubricates the fuel system in one treatment
- Compatible with both diesel and gasoline engines
Pros: Affordable, easy to find, and simple to dose; Good general lubricity boost for low sulfur diesel; Works across multiple vehicles in a mixed household fleet
Cons: No anti-gel and no real cetane boost; More of a general lubricant than a targeted CP4 specialist
7. Opti-Lube XPD All-Season Diesel Fuel Additive: Best All-Season Lubricity
Opti-Lube XPD has a strong following among diesel owners specifically because of its lubricity performance, which has scored at or near the top in independent fuel lubricity testing. For a CP4.2 equipped 6.7 Power Stroke, that wear protection is the headline feature, and XPD pairs it with detergents and a cetane lift so you get cleaning and easier starts in the same all season bottle. Owners who prioritize protecting the pump above all else often make this their year round additive.
The two things to be realistic about are availability and winter expectations. Opti-Lube is less commonly stocked in everyday stores, so most people order it online rather than grabbing it on the road. And while the all season blend offers some cold operability help, it is not a replacement for a dedicated deep cold anti-gel when temperatures plunge. In hard winter conditions, run the brand’s winter formula or pair XPD with a proper anti-gel. As a lubricity first all season additive, though, it is an excellent CP4 guardian.
- Industry leading lubricity in independent fuel testing
- All season formula with light cold weather operability help
- Adds detergents and cetane along with strong wear protection
Pros: Outstanding lubricity numbers, ideal for CP4 wear protection; All season blend covers lubricity, cleaning, and mild cold flow; Concentrated and economical per gallon treated
Cons: All season cold flow is not a substitute for a true deep cold anti-gel; Less mainstream, so it is harder to find on local store shelves
Frequently Asked Questions
Do I really need a fuel additive for a 6.7 Power Stroke?
It is strongly recommended, mainly because of the Bosch CP4.2 high pressure fuel pump. Modern ultra low sulfur diesel has much less natural lubricity than older fuel, and the CP4 relies on the diesel itself for lubrication. A quality lubricity additive helps offset that dryness and reduces pump and injector wear. On top of that, the right additive boosts cetane for easier cold starts, cleans injectors, and separates water before it can cause damage. It is inexpensive protection for an expensive fuel system, which is why most experienced 6.7 owners run an additive routinely.
What is the best additive to protect the CP4 pump specifically?
For pure lubricity, the additives with the strongest wear protection are the standouts. Opti-Lube XPD has long posted top tier lubricity numbers in independent testing, and Archoil AR6200 is built heavily around boundary lubricity and combustion improvement. Hot Shot’s Secret Diesel Extreme and Stanadyne Performance Formula also add meaningful lubricity while doing other jobs. If your number one goal is shielding the CP4.2 from dry fuel, choose a product that highlights lubricity as a core feature and run it consistently in every tank rather than only occasionally.
Should I use a different additive in winter?
Yes. Most lubricity and cetane additives, including the silver bottle Power Service Diesel Kleen and Hot Shot’s Diesel Extreme, are not anti-gel products and will not stop fuel from gelling in deep cold. For winter you want a dedicated anti-gel and cold flow improver such as the white bottle Power Service Diesel Fuel Supplement, which lowers the cold filter plugging point and disperses water to prevent fuel line freeze up. Many owners run a performance or lubricity additive in warm months and switch to or add an anti-gel once temperatures start dropping below freezing.
Can a fuel additive fix a rough idle or hard starts on my 6.7?
It can help if the cause is dirty injectors, low cetane fuel, or water in the fuel. A strong detergent and cetane additive like Hot Shot’s Secret Diesel Extreme run as a clean out can dissolve injector deposits and raise cetane, which often smooths out idle and improves cold starting within a tank or two. That said, an additive is not a cure for mechanical problems. If you have failing injectors, a bad CP4, glow plug faults, or sensor issues, no additive will fix that, and you should diagnose the underlying hardware. Use additives as maintenance and mild restoration, not as a repair for broken parts.
How often should I add diesel additive to my 6.7 Power Stroke?
For lubricity and maintenance additives, the common approach is to treat every fill up at the maintenance dose so your fuel system always has protection. For heavier clean out products, you typically run the stronger concentration occasionally, for example every several thousand miles or a few times a year, then return to a lighter dose in between. Always follow the treat rate printed on the bottle, since concentrated additives use a small amount per tank and overdosing wastes product without extra benefit. The key is consistency, especially for CP4 lubricity protection, where steady use matters more than occasional large doses.
Our Verdict
For most 6.7 Power Stroke owners, Hot Shot’s Secret Diesel Extreme is our top pick because it bundles cetane, real injector cleaning, and CP4 friendly lubricity into one trusted bottle that genuinely restores smooth running and power. Our runner up is Stanadyne Performance Formula, which earns its spot on the strength of being made by an actual fuel injection system manufacturer and offering balanced all season protection. Whichever you choose, pair your lubricity or cetane additive with a dedicated anti-gel like the white bottle Power Service Diesel Fuel Supplement once winter arrives, and your fuel system will thank you for it.
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