Do fuel/engine additives really work?

Question

We see additives ranging from octane booster, fuel injector cleaner, engine tune-up, engine oil flush, to engine oil stop leaks. But do these products really work in your car, and up to what degree do these products work.

If I were to use such products, I would go with STP or Liqui-Moly

Answer 1

I'm not a fan of any "cure in a can" type of fix. If they worked, they are only temporary until you get the car sold. Sealers work by attacking the seal material and causing it to expand temporarily stopping the leak. But that depends upon the seal material and the chemical make up of the sealer product. Radiator stop leak can plug your heater core making your heater useless. I'm sure manufacturers will say, "You're not using our product correctly." Right! STP and products like that are thickeners. Makes it a little harder for oil to leak past a seal. They claim it makes oil stick to parts needed lubrication during engine start.

Answer 2

depends on the additive My 1964 was designed to run on leaded fuel so I put a Lucas lead replacement Zinc

additive to replace the Missing lead



there is a carby and fuel injection cleaner which works But Used brake fluid will do the same Job



and Metholated spirits one pint to a full tank removes water in the Tank

Answer 3

Mostly no. But a few do work. See this post on Do addtives really work

Answer 4

Engine flush works well to clean the crankcase, and you will feel how heavy the oil filter gets full of crud after flushing. Techron works well. Slick 50 works well as I personally saw in an engine I tore down after 80,000 miles. STP is for worn out engines and does not repair them.

Answer 5

Some cars need more octane and good boosters work. If you don't need octane nothing happens.



Injection cleaner helped many cars years ago. Not just because it's cleaning the injectors but because it's cleaning carbon and sludge buildup on valves and pistons. Fuel is much cleaner today and I only face engines that need this help rarely.



Flush. What are we flushing out is my first question. There are likely deposits and sludge on an abused engine but a maintained vehicle has nothing to flush out.



I appreciate the idea of stop leak. In a high dose it swells rubber too much. "High mileage" oil has just a little with each service and will hopefully keep rubber from hardening and shrinking. The jury is still out but I've resealed plenty of engine that started leaking everywhere to pay attention and see if helps.



Many chemicals help certain situations. The ones I use are often not sold on stores shelves. You need nothing if you maintain your car.

Answer 6

Some of these products do provide some benefit, but the answer to how well they work lies in the nature of the problem you are trying to alleviate. None of them can FIX a problem however.

Answer 7

Basically snake oil, but Lucas does work quite well as an engine assembly lube for cam bearings.

Now that you can get Mobile1 for $32 5 quart bottles, that's the best engine oil you can expect to get.

If you have an old engine(s) without the hardened valve guides, they do sell the tetraethyl lead additive.

Answer 8

If you need a higher octane level, it costs less to buy higher octane fuel. MOST vehicles are designed to use the lowest octane fuel sold and won't benefit from higher octane fuel.



While fuel system cleaners CAN help occasionally, there are actually cleaners included in the fuel you purchase at the pump, and you are ALREADY getting them.



As oil circulates in a closed system, the only way to clean oil is called an oil change.



Anything that claims to stop leaks does so by CLOGGING the leak and tend to clog more than just the leak.



Short answer, NONE of them are long term solutions for anything.

Answer 9

You don't need octane booster unless you're running 13:1 compression in a built motor and 103 octane race fuel is unavailable.

The only good and safe way to stop oil leaks is to repair the leaking seal or gasket.

If you use oil flush in a slugged up motor all the sludge gets into the oil pan and plugs up the oil pump and pickup which then starves the motor of oil and seizes the bearings.

Most folks don't need fuel injector cleaner due to the clan gasoline with additives being produced.

if you just have to try some I'd only use Chevron's "Techron" products.

Some motors tend to carbon up. Seafoam upper end cleaner works.

One additive that is worth using is LUCAS power steering additive. It reconditions dry power steering rack seals and with in 6 to 8 weeks the rack seals will stop leaking. I've used it on many customer vehicles and use it in my own car as a preventive maintenance product that actually works!

Answer 10

They are all snake oils. Fix your vehicle properly.

Answer 11

Some of those stop leaks that shrink seals work, but, you have to keep using them. The $20 variety used car dealerships use is best. Techron and Aircraft fuel additives are best for gas. Most good gas has plenty of cleaners in it, already. Only if your vehicle sat a while with old gas would these cleaners really be useful. There are Zn and P additives for older engines that required leaded. MdS2 low friction additive for flat tappets. (Note. TEL is No longer sold as an Additive. Illegal. Leaded 100LL and racing gas still available at airports, race depots, and motorcycle shops.)

Answer 12

Only fools buy these useless chemicals. Stupidity is what the manufacturers rely upon.