Stanadyne 12 Performance Formula

Stanadyne Diesel Fuel Additive Review – Best Engine Protection


Stanadyne 24 pack Performance Diesel Fuel Additive

A few months ago I bought my 2019 F-250 from a Chevy dealer, if you can believe that. It had 24k miles on it and was in good shape for being used. It’s my first diesel, so of course I had a lot of questions. One of the first things the mechanics recommended (notice I didn’t say salesman) was to get a fuel additive, and they recommended Stanadyne. Of course I asked if an additive is necessary at all, and they said something like “Well, you can run without it, but fuel injector replacement is VERY expensive”. Nuf’ said.


Diesel fuel is great. It’s easier to produce, and burns without a spark. Diesel engines produce massive amounts of torque- perfect for pulling heavy loads. They can run for hundreds of thousands of miles with proper maintenance.

But, diesel fuel has drawbacks. With low temperatures the fuel can gel, preventing your engine from starting. Diesel fuel retains a small amount of water. Water, of course, doesn’t burn at all, and causes corrosion when in contact with engine components. Finally, if the fuel has a low cetane count (harder to burn), your efficiency will be degraded.

Fuel additives can counter some of these drawbacks.

  • For water removal, you want to look for a demulsifier such as Stanadyne. What this means is that the smaller water molecules that would normally pass through the truck’s fuel filter are bound together into larger droplets that the filter can then remove from the fuel, via the Aquablock membrane. What you don’t want to get is an emulsifier. These products further suspend the water molecules in the fuel, effectively mixing them together. This can cause erosion of injectors, thinning of oil coating cylinder walls, and lower cetane. Ford will not warranty engine work if rust is found on the injectors.
  • Cetane number is an indication of the time between initial ignition and pressure increase. The shorter the time, the higher the value. In essence, higher cetane number translates to faster ignition. The USA requires a minimum value of 40 in the lower 48 and Hawaii. Ford recommends the same, 40. So you don’t need to boost the cetane levels in your fuel and can run without it (unless you live in Alaska). However, Stanadyne does add up to 5 points to that value. This increase can lead to better fuel economy, reduced noise and easier starting.
  • Other benefits include better engine lubrication for longevity and detergents that will clean components such as injectors over time.

Using Fuel Additives

Stanadyne comes in several different sizes, and 8 oz treats 30 gallons of fuel. You can order a 24-pack of 8 oz bottles, or a 12-pack of 16 oz bottles, or one of several other combinations if you prefer. These bottles have a long neck so you don’t have to worry about spilling or using a funnel when you’re adding it to the tank. My truck has a 34 gallon tank, so the 8 oz bottles work well when I’m low. If you’re in a state like Oregon, ask the attendant if they’ll just add the 8 oz bottle to the tank for you before they pump.

Stanadyne 6 Performance Formula

You can order a 64 oz jug as well, but then you have to mess with a funnel, or some other clever solution to keep from pouring it down the side of your truck. Fewer bottles means a lower environmental impact, and of course buying in bulk gets you a lower price, so it’s up to you.

Benefits of Stanadyne

  • All-purpose fuel additive
  • Cetane boost
  • Water demulsifier
  • All-season use
  • Not specific to diesel manufacturer or model years
  • Detergents clean and prevent build-up of contaminates on injectors
  • 2-year shelf life
  • Antioxidants keep diesel stable for a year

Who’s it for

If you have a diesel truck, or most any diesel engine for that matter, you’ll want to use a good fuel additive. It does cost a few bucks per tank, but it will save you thousands when your buddy is having the body lifted off his truck to get to the injectors at 100,000 miles.

What I Like

  • No alcohol
  • Water demulsifier
  • Cetane boost
  • Easy to use long-neck bottles

What I don’t Like

  • No specific anti-gel component
  • Stanadyne works over time. You must be patient to see improvements.
  • More expensive than some other brands

Final Thoughts

If you are concerned about engine life, fuel efficiency, shortened maintenance intervals and dirty exhaust, Stanadyne Diesel Fuel Additive is the best all-around product you can by. There are others, but based on research and recommendations of several mechanics, this product is the way to go.

If you’ve had any experience with this additive, or any other engine treatments, or if you’re interested in learning more, drop a comment below.

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