Fuel Additives Poll

[JanGeo]

Actually you want the water in small droplet size not evaporated into water vapor so that when the ignition boils the water droplets they turn to steam and expand.
Gasoline is composed of hydrocarbons and when it gets on hot surfaces the hydrocarbons react and will leave carbon compounds which have to be cleaned off valve components or you get a fouled valve.

[trollbait]

^The problem with that is the 'warnings' about raising the amount of additives to your gas that increase it's percentage of 'water retention' chemicals to beyond 10%, E10>. Alcohol is soluble with water. Now, I've used Sea Foam for instance, but it apparently can contain 10-20% of Isopropyl alcohol.

What are these warnings? Is it concerning phase separation? Undissolved water, water/ethanol mix in the gasoline can cause problems in fuel lines and engines. If you don't want to drain the tank, to get it out safely, it has be dissolved and dispersed in the gasoline using a solvent with polar and non-polar properties. Acetone and ethanol will work. Isopropanol is better because it's not hygrophilic.

Too much hygrophilic compounds can be a problem in stored gasoline, since they'll increase the water content over time, possibly to phase separation. Not all 'water retention' compounds are hygrophilic though.

PS: It appears adding salt to rubbing alcohol will cause the water and IPA to seperate. So if you don't want to add the water in the rubbing alcohol, and don't have Iso-heet....

[add|ct]

^Nice break-down. I wasn't aware of those particulars and the details, but I figured it perhaps wasn't worthy of just a generalization like the fear spread regarding Sea Foam(anything with alcohol content) and E-10 for example. I use Sea Foam once a year in my vehicles; at most, and it's usually half a can to a half tank of gas(5-10 gallons). I recently bought several of the Shell V-Power Fuel System Cleaners on clearance for 95 cents per bottle at AAP. Aside from running a tank of premium after several thousand miles, I don't reckon any thing else is needed as far as cleaning. I have been trying MMO some and TC-W3 will be next, then perhaps a blend of each.

[VX_Arky]

Originally Posted by Gforce

Very interesting information in this thread. Has anyone (but me) notice an increase in actual fuel efficiency using an additive and if so, which one?

Ok you guys are going to light me up over this but I'm going to share it and it is true. Every summer for more than a decade, I have taken my 4Runner down to the Gulf in Florida as we vacation there once or twice a year at Destin or Fort Walton Beach. I fill the truck up and use STP Gas Treatment with every tank that I use and I have ALWAYS gotten a 10% increase on fuel efficiency driving the same manner that I make other long, highway distance commutes.

I voted that I believe these are a waste of money but that's only when it comes to city driving. When I take a long trip, I have noticed a considerable difference when I use the additive and when I have not.

OK, fire away. I'm ready to be ambushed now.

[imzjustplayin]

have you done the cost benefit analysis? You don't want to have an additive that costs $5 a tank but only save $4 per tank of gasoline. Only thing I can think of is that these additives make the car run lean which helps with cruising fuel economy.

[VX_Arky]

The savings is significant enough for me to do it each year. It's not a lot but it does seem like the car runs better with the STP in it. I spend $1.75 to increase my fuel efficiency a little over 10 percent actually, which nets me an extra 45 miles for the tank. An extra 45 miles would be about 2.5 gallons otherwise, which is about $10 at today's gas prices. That's a net savings of $8.25, and the truck seems to drive slightly smoother.

[shatto]

Originally Posted by Arky

The savings is significant enough for me to do it each year. It's not a lot but it does seem like the car runs better with the STP in it. I spend $1.75 to increase my fuel efficiency a little over 10 percent actually, which nets me an extra 45 miles for the tank. An extra 45 miles would be about 2.5 gallons otherwise, which is about $10 at today's gas prices. That's a net savings of $8.25, and the truck seems to drive slightly smoother.

Therein lies the problem. Outside expensive tests with very sophisticated measuring machines, there is only one way for us average types to know if the purchased product performed:
* Fill the fuel tank completely. Write the odometer mileage on the receipt.
* Use 1/2 to 2/3, or more, of the fuel before fueling completely. Write the odometer mileage on the receipt.
* Subtract the low from the high mileage to see how far you drove;
divide the miles driven by the gallons purchased and you have your Miles Per Gallon.
* The only way to be accurate is to get an average MPG over a minimum of three fillings.
*NOW you will know if the additive has worked.

[VX_Arky]

I use two tanks down and two tanks back every time and I've always done the math on figuring out the fuel efficiency and I always top off the gas tank so the numbers are accurate. Again, I'm not a scientist, just a guy doing his part but STP Gas Treatment has had a positive effect for me. And, like I said, the truck appears to burn fuel and drive smoother but there is nothing other than my personal observation and perception to substantiate that.

[bowtieguy]

its note worthy that 60% of those replying to the pole use some type of fuel additive.