Fuel Treatments...thoughts?
 

I figured this would best be considered a "tuning" question...

What are your thoughts on fuel treatments? I just bought my first (used) cobra with 11k miles on her and was thinking of running a gas treatment through the engine. I've heard conflicting information regarding it. Some say it is worthless, harmful, or it does, in fact, work well.

PULP at 98 octane is plenty for a street car, keeps the inlet and chamber carbon to a minimum.

With an EFI car in closed loop, fuel economy (cents per kilometre) ends up cheaper because the car gets better MPG.

Last spring I revived a motorcycle that had been sitting for about ten years. Even with determined soaking and cleaning, some of the smallest passages in the carburetor were not completely clear, so it ran and idled a little rough. I researched the same question you asked and ultimately decided to try a product called Sea Foam. I added it in the recommended amount to the fuel and within three gallons (140 miles) the bike ran noticeably smoother. I don't know if it was the Sea Foam or just running a tank of fuel through the carb that made the difference, but I don't think it hurt anything. ... You may hear lots of strong opinions about additives, but I doubt you will discover any objective evidence supporting them.

X 2 On Tommy's Sea Foam. Used on 3 different cars over time.

Sounds like you're looking for a fuel system cleaner. Sea Foam has an excellent reputation. Over the years, I'v used B-12 Chemtool and Chevron Techron with good results.

First of all, in 1965 no gasoline had any Deposit Cleaner Additive (aka Techron). All name brand gasolines today have anti-oxidants, corrosion inhibitors and deposit control additives. Sure, in extreme cases you can use a fuel/carb cleaner and see improvements. For the normal day-to-day stuff it is a feel-good thing. Emotionally you know you spent some money and you really think it helped. But really, it did not help anything! Water is by far our biggest worry with 10% ethanol. Keep the water out and you won't have any problems. Since most of us park our Cobras inside, we don't have anything to worry about. Has anyone had problems with their Cobra in the spring after sitting around all winter? I would like to know.

You didn't say if the car is carb or FI
 

brewme For fuel injector cars we have a pressurized cleaner that go into the fuel rail and clean JUST the injectors and combustion chambers. A couple of companies sell this stuff at Dealerships. It comes with a warrantty and does help on car that have sat for months. Granett, BG, and dealerships have there own cleaning fluids. Carb system is a pour into the gas tank and down the inlet with the motor running. Sea foam, One of the best on the market. The cleaner we use at the dealership are NOT to be USED or POURED into the fuel tank. It will over time damage the electric fuel pump and shorten the life of it. Also keep a min of 1/4 tank of gas in the tank. This helps cool the fuel pump and extends the life of it. This is more important in the summer time.
Gas stablizer is another good product to use before putting car away for the winter.
There are partials in the fuel that get through the fuel filters and end up in the injectors or passages of the carb. On a carb the best way to fix this is remove from motor, sit down with a complete diagram and gasket kit and rebuild it. clean everything, don't mess with the adjustments until carb is back on motor and running.
There are a couple of companies that clean injectors and flow test them and blueprint if wanted. They flow within 2% when done. This is great from smoothing out a motor.
Last note, over the last couple of years, the problem of rubber hoses and ethanol is popping up. Ethanol is breaking down the rubber for fuel lines and small black partials are getting into the carbs and injector giving drivablity problemsd of rough idle, stumble, poor power, running lean, and a list of other issues. All hi bred cars and trucks now run plastic fuel lines and emmission systems due to ethanol or alcohol. This will tell you something has changed.
Most important thing, read the instructions BEFORE using the product in ANY car or TRUCK. Last month a guy with a diesel screwed up his fuel system, $12,000.00 dollars for a new system, injectors, glowplugs, lines, heater for fuel, Fuel management module, filter housing, 26 hours for repair, front to back of truck with the wrong additive being used in the tank. Truck runs but smokes on accelleration more than normal, Compression is at bottom of spec and has blowby. My lastest info on the question. Rick L.

Great responses! Thank you all for your time posting.