Fuel Additives: Do They Work?

Car by the side of the road

Source | Jay Toor

You may be wondering if fuel additives are effective and if they work as well as advertisements claim. After all, the Environmental Protection Agency (EPA) requires that all fuel sold in the U.S. contain a minimum amount of deposit-control additives to prevent a dangerous buildup in car systems. Isn’t that enough?

Well, it depends. There are benefits to using fuel additives (read on to find out what they are). But it’s important to choose the right additive and to have realistic expectations. Here are a few things to consider.

Types of fuel additives

One point of confusion over fuel additives comes from the baffling array of available products. There are many types of fuel additives, and they aren’t one-size-fits-all or miracle cures. Each additive aims to relieve a different pain point. Here are a few of the most common types of fuel additives and what they do.

  • Fuel stabilizers. These are designed to maintain fuel’s efficacy during periods of disuse. They prevent hard starting due to gas separation and engine corrosion in seasonal vehicles like boats and RVs.
  • Octane boosters. These are designed to increase fuel’s octane rating. They include a lubricant to protect the cast-iron valve seats often found in classic cars.
  • Fuel injector cleaners. These are designed to protect fuel injectors from the gumming properties of Ethanol. Clogged fuel injectors perform poorly in cold weather and have sluggish acceleration.
  • Anti-gel diesel additives. These are designed to unclog diesel fuel filters and reduce hard starting during extremely low temperatures.

The bottom line is it’s all about finding the right additive for your vehicle’s needs, and then use it according to directions. Using an additive correctly can keep your engine working well and prevent costly repairs.

Pro Tip: Look for fuel additives that contain polybutene amine (PBA), which can clean out deposits from carburetors, fuel injectors, and intake valves.

Will an additive improve my fuel economy?

Not likely, according to a study conducted by the EPA. They tested more than 100 products claiming to improve fuel economy by 12 to 25 percent, including additives. Their findings? None of the products stacked up to their own claims and many could cause actual harm to an engine.

Now, will your vehicle run more efficiently if you use an additive to, say, de-funkify your fuel injector, and will better gas mileage be a natural by-product? Maybe. But if better gas mileage is your primary aim, you’ll be disappointed with the results. If you’re looking to save money on gas, there are plenty of other effective ways to improve fuel economy without ever leaving your driveway.

A word of caution

Don’t overdo it. Using too much of any particular fuel additive can damage sensors and other features. You’ll end up spending more in the long run than you would have dealing with typical deposit damage. So select the right additive, read the instructions carefully, and check your owner’s manual when in doubt.


What do you think? Is there an additive you’ve found helpful? Share your thoughts with other vehicle owners.


  1. Lucas Gas Additive works very well, it does help get extra mileage.I recommend using a bottle with each fill up.
    I also recommend Lucas Oil Treatment with each oil change.
    I think Lucas makes some of the best products on the market today. I would recommend them to everyone.

  2. The ingredient you want is polyether amine, which isn’t found in every brand. The known brands to contain PEA are chevron Techron, any Gumout with the label “Regane”, as well as Redline and Amsoil fuel system cleaners.

    There is plenty of junk out there that doesn’t contain PEA and the two worst ones you can buy are Lucas or STP, of which contain no PEA at all! Just a proprietary blend of mostly kerosene carrier.

  3. Bill Hellmueller says:

    well the information on fuel additives was not very helpful.. No where did it mention some brands that are good to use….

  4. Brad Grems says:

    Anyone know of a good additive for engines designed to burn leaded fuel. These are mostly older hobby and collector cars that need something to protect the valves and valve seats, which is what the lead used to do.

  5. Sea foam. Been around since the great depression. I had a mechanic of 50 years sell me on this product. I put a can in 2 or 3 times a year with a fill-up. I have 170,000 miles on my 2003 Tacoma and it runs like new.

    • I also have had great results with Sea Foam. Resolved idle and hard start problems with 150 Hp Blackmax outboard and eliminated a engine shut down problem on a used Johnson Faststrike 150 out board on a nice used bass boat I bought. Used one can per 15 galoons of fuel in both cases as recommended by a sharp old marine engine Tech yesrs ago. Good advice then and now as far as I am concerned.

  6. Peggy kingery says:

    I used seafoam as directed and my van hasn’t been the same since. I have had to take off throttle body and clean. Still does the same sputter and sometimes will start most of the time not. I wonder if the seafoam didnt cause some crud to plug it up somewhere.

  7. Robert Mansour says:

    Have any of you ever tries Lubrication Engineers LX 2300 Gasoline Additive or their BTU+ Diesel fuet additive? … I’ve tried their LX 2300 and I not only felt a power boost, but I’m using less furl for the same driving distances and I get 8 fillups with one bottle, the Mix ratio is 1:400
    Please let me know If any of you have tried it

  8. OnlyGermanCars says:

    Liqui moly valve cleaner is the best if you can find it. Made in Germany. If not, use She’ll nitrogen premium gas. More costly, but in the long run, cheap investment for your engine.

  9. Techron, Sea Foam and Marvel. Take your pick. New cars, Techron. Broken in 50-100.000 miles = Sea Foam. 100.000 + miles, it’s a toss up between Seafoam and Marvel. Sea Foam for highway, Marvel for local.
    None of these mostly money-wasting additives can replace using premium Gas though.
    P.S. @ Only German Cars. Liqui Moly is almost non existent here in the states. But it works well. 400.000+ miles on my Benz D Car with an occasional gallon of #1 Kero and it runs as good as it did the day my grandfather brought it here from the old country.

  10. 2003 Chevy Silverado 6.0L says:

    The Chevrolet dealer said I had some bad injectors. I thought I’d try some injector cleaner first. I saw a ” before and after” Youtube video of piston carbon deposits after using Gumout tune-up fuel treatment. It sold me. I tried it in two tanks of gas and my truck is running like new.

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