Gumout (brandname) sells many products; one of them is an engine cleaner and and another is an octane booster.
My posts have been discussing the octane booster.
The chemical composition of both is very similar...

 

Minor hi-jack:
So should we be doing some kind of regular additive? I'm of the mind that most brand name gasoline has such additive in it and, for any decently maintained car in normal conditions, the aftermarket bottles are a nice place to burn any cash you don't need.

 

Well, before I used the last bottle of Gumout Fuel Injection cleaner, the car got to the point that it would idle "rough" while sitting in traffic with the AC on (for example). "Rough" means the engine sounded and actually felt like a cylinder was misfiring. Also, it would misfire (sometimes) significantly at low RPM's under load (like when taking off from a start.

I know rough running conditions at low RPM's is sometimes caused by bad plugs, wires, or the "coils". I remember someone at the dealer telling me these cars have coil over wires. However, if any of these conditions were the cause, I wouldn't think the fuel injection cleaner would improve the idle or or how the engine runs through any other part of the RPM range.

Also, when the Gumout fuel injection cleaner is in the fuel, I can bark the tires "even easier" than normal. It just seems to have more power. It idles smoothly sitting in traffic with the AC on, accelerates smoothly from a stop, even with the additional load of the AC or hard acceleration...it just runs better.

I checked and was told by an SA at the dealer that the replacement of the plugs (on my DBS at least) could be as much as $3800. While I know this is an Aston, that just sounds ridiculous to me. I am searching for other options to get the plugs replaced. My regular Indie that did all of my Jags out-of-warranty does not want to do the Aston (for some reason).

 

A couple of questions:
How many miles on your car?
Do you use the car to commute in?

Although it's not normally needed in today's modern engines, it sounds like you might need an "Italian tune up", or a day at the track.

http://en.wikipedia.org/wiki/Italian_tuneup

 

Mileage is 48,684...it is my daily driver.

Italian tune up sounds good, but as you say to safely and legally do that I would need to do it at the track.

 

If you're having actual misfires, that should show up on a OBD2 scan.

 

It's not throwing any codes, but I will hook up my OBDII scanner today and see if there are any codes in memory

 

The purpose of adding octane boosters is to allow the ECU to maximize its timing advance as much as possible without detonating/pinging. In a car with knock sensors and adjustable timing (most modern cars), using octane booster ensures you are using 100% of the cars potential instead of around 95% (which is what most run at given the lack of consistent good quality gasoline). Modern ECUs will stop getting benefits once you pass 96 octane, anything higher than that and you are just wasting money. By allowing the ECU to run at its max, the powerband becomes incredibly smooth because the ECU maxes out all the parameters, whereas normally its constantly having to make adjustments on the fly 10x a second (if not more). Put a car on a dyno and do a before & after run and compare... You may only make 4-5 hp tops... The the shape of the curve will be increadibly smooth. Its the smoothness you notice the most, not so much the power.

The best over the counter injector cleaner is seafoam... However it is not the best injector cleaning service. If you really want to kake your heads and combustion champers spotless as well as clean your cats and everything else, I highly recommend the BG injector cleaner service. This service actually connect directly to your fuel rail (with fuel pump fuse removed), then the car runs off the entire can of BG injector cleaner until it is completely finished. You will see lots of smoke come out the tail pipes, this is normal, its all the carbon & gunk being burned off inside the engine as it comes out the tail pipes. Normally you only do a service like this at roughky 50k miles or mroe, however our cars do run notoriously rich so you could justify doing it as early as 30k.

Most over the counter stuff will not do much, it may slightly improve the feel but its no where near as effective as the methods I have described above

 

The octane rating basically tells you how fast the fuel burns, your ECU has a table it uses to calculate timing based on certain factors (rpm, air temp, air flow and fuel are just a few), if your ECU is not programmed to handle 100 octane, you will see little to no gain in HP or anything else and it can even add carbon build up from the unused gas. Another thing, your ECU has to learn to handle different fuels, example being when gas refiners change from summer blend to winter, ever notice your runs a little rough, that is your ECU learning the new blend.
I would like someone to show a before and after on any carbon cleaner, because I do not see how a little bit of cleaner that burns off in a half a second or less can clean off carbon from your engine. Just my 2 cents.