I'm not sure if this thread is in the wrong category, so I won't be surprised if a mod moves it.


Apparently there are fuel additives that you use at every gas fill-up (versus the once in a while fuel system cleaners) that advertise that you will get better mpg and experience reduced engine friction.

Specifically, I know someone in real life who says that he saves almost 1/4 tank of gas when he uses STP carburetor and STP gas treatment together. I didn't believe it, but he says he's sure of the results. What's more surprising is that his car is fairly new.

So, what has your experience been with STP gas/carb treatment? If it did work, why don't gas companies include these chemicals in their gas?

I googled the issue and only came up with these conclusions:

-many people on forums agree that most additives do not work and can harm the engine, but do not quote any well-documented resource.

-many people on forums also agree that fuel system/deposit cleaners MAY work only on vehicles that are old/have been neglected, usually based on personal experience (it worked for them). Many also say that the Techron fuel additive is used in auto dealerships as a service item.

-of the in-depth experiments on additives that I could find, additives are generally shown not to work. Some live up to their claims (even improving mpg), but wreak havoc on other systems.

-I couldn't find any scientifically viable resource regarding the effects of STP gas/carb treatment. The only thing I could find were user reviews where the drivers sometimes say that they save gas when they use these products (similar to the person I talked to in real life).

 

Gasoline has additives to keep injectors clean, etc, no need for more except on rare occasions. Rare occasions being an injector is actually is starting to have a problem, this would result in rough running symptom.

The dealer does use Techron but they disconnect the fuel line and run it straight into the injectors not pour it into the fuel tank.

Older cars may be have more problems because of ethanol use in vehicle not designed for the fuel.

It is no surprise you are finding only subjective information.

This stuff does work but in most cases is not needed.

Might check past posts at the Toyotanation website on fuel additives and opinions.

 

This discussion has been going for years on bobistheoilguy.com. If you want to read until you pass out I suggest you check out the site.
I have used Techron but have had surprisingly good results with Redline SI1. Supposedly it has a high percentage of PEA - a synthetic cleaner.
I have tried the majority on the market and most don't seem to have any result I can identify.

 

Concur.

Modern fuels already have cleaning chemicals. If a system isn't plugged up, cleaning may not make it any better.

Techron was used by Toyota dealers but injected into the fuel rail, not via gas tank.

Most of these products have the same common chemicals and very high mark up on price, which is why they are heavily promoted.

If your engine is running OK, you don't need an additive.

 

Agree with above. I've never seen any results from using additives.

 

Iam a true believer in Sea Foam It's some great stuff always got some in the shop

 

I used Sea Foam in a 95 Accord and I didn't notice a difference. I'm sure all that white smoke out the pipe did mean that it had done something though. I have also heard some horror stories about it though.