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Title says it all. Not much in the archives on this. With my old Corvette I ran GM's gasoline additive every 3 months or so.

Recommendations?

Regards,

Greg
 

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If it ain't broke, don't fix it?...


Last 03 5 said:
Title says it all. Not much in the archives on this. With my old Corvette I ran GM's gasoline additive every 3 months or so.

Recommendations?

Regards,

Greg
 

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I use STP (black bottle) every 2-3k miles and it's always a little sweeter and crisper afterwards, do it for the first time and you'll be surprised just how sweet the cars runs at a £5er it's worth every penny !
 

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The FI cleaner won't do anything that good gas already has. I'd suggest using a major brand of "fuel system cleaner" (which is the strongest formulation) in the last tankful of gas before an oil change. Contaminants that escape the filter are then changed out.
 

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I would worry about fuel additives. Many can foul O2 sensors and cause more problems down the road. The only car that I ever ran injector cleaner through was my Triumph, but the O2 sensors ran open loop (IIRC, after we jury rigged some problems with the wiring harness), and the injectors needed cleaning every once in awhile. I wouldnt worry about it in a beast.
:cheers:
 

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Interesting topic...

What are the practical differences between STP Injector Cleaner and STP Complete System Cleaner?

Which is the optimal way of deploying it: with a small volume of petrol, or with a full tank?

David
 

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DavidS said:
What are the practical differences between STP Injector Cleaner and STP Complete System Cleaner?
Which is the optimal way of deploying it: with a small volume of petrol, or with a full tank?
David
Generally the heirarchy goes from "gas treatment" to "FI cleaners" to "fuel system cleaners," weakest to strongest. Products in the latter category almost always claim to be able to be able to remove combustion chamber deposits, which is my initial screening criteria in the store. I used the STP fuel system cleaner when it was introduced in the American market and remember asking STP for, and receiving a very convincing brochure from them that depicted before/after scenarios.

Most of the FSC's call for mixing the bottle in 16 gallons of gas. I always use less gas, usually 12 gallons or so.
 

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Thanks, BKH!

I wonder how the FSCs clean carbon deposits...? If the depisits fall off in chunks, there would seem to be an uncomfortably high risk of cylinder wall scoring. On other hand, if the deposits are dissolved or at least broken down into tiny enough bits not to cause problems if caught between the compression ring and the cylinder wall, it would seem to be a really good idea to clean regularly.

Anyone heard of any drawbacks with the STP Complete System Cleaner?

David
 

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Just looked at the STP website (www.stp.com).

It is a nice website, but I noticed two things:

1. In the FAQ:

"Are STP® products safe for two-cycle engines? four-cycle engines?

STP® oil and fuel additives have been specifically formulated for use in four-cycle, gasoline engines. Extensive testing in these engines has covered a broad range of passenger car usage and has clearly demonstrated the value of our products in these applications. However, we have not evaluated the performance of our products in two-cycle engines. Therefore, we do not currently recommend that they be used for two-cycle applications"


If you read carefully, they do not answer their own question.
All they say is testing has clearly demonstrated value in the applications. It does in no way state there have been no issues. I wonder why...

2. In some of their product descriptions it says as a positive thing that the stuff is made from Jet Fuel. If that means normal aviation jet fuel, that is some of the worst stuff imaginable for a car engine.

Have you ever looked at the engine cowls of a turboprop aircraft? Have you noticed the soot? That is jet fuel for you. Jet fuel is basically kerosene of the lowest quality. It is all about making a fuel cheap enough to burn by the tons. An airliner uses about one ton per 100 km. (Aviators please correct this if not correct.)

STP say they "use no corosive chemicals such as alcohol in their products". Since when is alcohol corosive? You americans of the mid-west drive on about 30% alcohol when you fill the car up. That is how corrosive alcohol is to car engines.

(Anyone who remembers that US petrol is corrosive to Nikasil alloy used in certain engines from BMW and Porsche among others, should know that it is the high sulfur content of certain US petrols that is the problem, not the alcohol content.)

Anyway, although their marketing is not absolutely convincing, I doubt that a few drops of jet fuel would cause any problem when mixed with a tank of petrol, so if everone here thinks STP FSC is a good idea I might very well give a try.

David
 

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There is a product my dealer uses that is BMW-approved (perhaps even branded) for this purpose. I'll try to find out more about it next week but it's SOP for problems or during major inspections as I've seen the techs add it on a number of occasions.

I believe that methanol is considered corrosive and is now generally regarded as a no-no, ethanol is OK and is what is used in gasoline. Inexpensive deicers used to use methanol, for example.
 

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BKH,

Thanks for looking into the BMW cleaner!

I know methanol is extremely tough on certain plastics, but so is ethanol to some degree too. Maybe Methanol in the fuel causes breakdown of the oil?

I don´t know, but is there a thin oil film on the cylinder walls above the compression ring? If so, I can see why methanol would be very bad, washing the oil-film away on each intake cycle.

You run model airplane engines on methanol, so it can´t be that bad for metal, can it?

David
 

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This thread is still young, I'm surprised no one has brought up Techron yet.

30% alky on a full tank? that seems high, but it would have ethnol as the mix as Methnol would be hard to keep mixed and start when cold.

When methnol sits for a time it will attract water and also turn to jelly unless the system is pickled with fuel and oil.
 

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DavidS said:
Have you ever looked at the engine cowls of a turboprop aircraft? Have you noticed the soot? That is jet fuel for you. Jet fuel is basically kerosene of the lowest quality. It is all about making a fuel cheap enough to burn by the tons. An airliner uses about one ton per 100 km. (Aviators please correct this if not correct.)
David- The issue with sooting on aircraft is a two part problem. First off they are not cleaned often, and second there is a limited exhaust duct for soot to catch on. But I do agree, in terms of aviation fuel (of ANY type) and cars, it doesnt mix at all. Jet-A might run in a diesel engine, but putting it in a normal car is bad bad bad.
It's too hard to generalize on fuel burns with aircraft, as all are different. Even two 737's made within the same month will have a slightly varied fuel burn.
For comparison, older 727's burned about 3500lbs per hour per engine. That is a lot! Newer Airbuses like an A320 burn around 2200lb/hr per engine IIRC.
:cheers:
Sorry for being OT.
 

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On the OT:
Never run Av-gas in a car, the fuel was made to run at higher altitudes.

Model plane fuel uses methnol,nitro,oils in the mix but they are small diesels.

Now back to the subject:
I like the questions of where it goes?
Well out the exhuast to the O2 and Cats to coat them if not done right.
 

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The issue with running 100 low lead in a car (most common av gas for GA airplanes) isn't the fact that it is made to run at high altitudes but that it is still leaded. Leaded gas in an engine designed for unleaded leads to very expensive repairs of CATs and other exhaust hardware. Kiss the O2 sensors good bye, and prepare for the joys of limp home mode.
In 10 years of flight training I have never heard that the fuel composition of 100LL is for high altitude operation. It can't be true though, as turbocharged GA aircraft still use 100LL, and they get pressures equal to sea level until the wastegate fully closes. We just do what every other internal combustion engine does; pull the mixture out so the fuel/air ratio remains within the limit of combustability, and accept the power loss (unless the aircraft is FI).
Ok, sorry again for getting OT.
:cheers:
 

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Here's one experience that is worth mentioning..


On an old E30M3 I had a ticking noise that wasn't cams and sounded like injectors, so I used STP cleaner on two tanks and the niose didn't change. BUT the car ran heaps better afterwards, lots crisper, cleaner revving, seemed quicker and very willing to rev, smoother etc, etc

I then had the injectors cleaned by ultrasonics (quite expensive) They seemed NO different to how they were after cleaning with STP.

I finally replaced them ! Assuming that one of the injectors was faulty (convinced it was an injector making the noise) The car had done 70k miles or so and was 15 years old. So In thought what the hell.

When they where replaced (expensive) Again they were no different......:crying2:

I concluded that the black bottle STP cleaner was good enough for me !
 

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Still OT

From Chevron fuels
"It is carefully manufactured, blended and inspected to achieve optimum performance while meeting the wide range of strict temperature, altitude and power requirements of aircraft operation. Due to differences in physical and chemical properties, motorcar gasolines should not be used in aircraft engines and aviation gasolines should not be used in automotive engines."

After looking a the MSDS reports I'm never going to use a noozle without gloves. I'd suggest finding your favorite fuels and looking at the sheet so we all know whats in the stuff we feed our cars.
Sometimes it has fuel system cleaners added.
 

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The only reason Chevron states that is the fuel resists going in vapor lock, which varies with altitude. It really is the same deal as automotive gas too. Modern cars would not have an issue with this, and it isn't the reason.
The chemical composition of a fuel doesnt care at what altitude it is burned, it cares if it is in the correct air fuel ratio. Not trying to beat you up, but it is important to have correct info on subjects.
:cheers:
 
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