Q How do you know it's working?
Possible DIY (Do It Yourself) tests include:
Start using a magnetic sump plug:
Make a note of how much metal collects on the sump plug normally (or take a picture) and then check how much you get after adding Xcelplus.
2) Fuel Economy
Use the same type of petrol each time (E10 (ethanol), octane ratings 91, 93, 96, 98, etc...) preferably bought at the same service station and using the same pump. Fuel can vary even if you use the same chain to refill e.g. BP or Shell.
E10 (10% ethanol) in particular can have a marked effect on mileage (~10% less than petrol without ethanol).
Gas (LPG) is a mix of butane/pentane and thus can vary a lot e.g. Some gas is pentane entirely which will give better mileage than a mixture of both gases.
Test across all cylinders and write the readings in your log book before treatment. Repeat compression test after treatment.
Make a note of engine noise noting the location and type of sound. Use a sound meter if possible.
Note how long it takes to start the vehicle before and after (number of turns)... or how hard it is to turn the engine over. How cold the day is makes a big difference N.B. Starting on cold days drains the battery more than on warm days and is likely to show the greatest improvement.
Measuring amperage or starting voltage is often a simple way to establish easier starting i.e. lower voltage or lower amperage means easier starting.
6) Exhaust emissions
Note the colour of your spark plugs before & after. The lighter the plug the cleaner the burn.
Note the amount of carbon collecting at the end of your exhaust pipe. The less carbon the cleaner the engine.
Note the amount of smoke your vehicle blows and the colour (blue or black) before & after.
Your local mechanic probably has an emissions tester: Levels of 02 (oxygen), CO2 (carbon dioxide), CO (carbon monoxide), NOx (Oxides of Nitrogen) and total level of HC (unburned hydrocarbons). Do a before and after test.
Use a dynamometer as "seat of the pants" testing is notoriously inaccurate. Engines become more responsive after treatment N.B. Quieter means more power not less!
If you keep a log book you should log any breakdowns before and after. Note if they change. Most engines today are very reliable so this is no longer as useful as it used to be.
Many electrical parts last longer because they are less stressed e.g. Brushes in starter motors last longer as it takes less power to turn an engine over and less turns to start. Batteries will last longer because it takes less power to turn over an engine. Spark plugs can last longer because they are less likely to become fouled.
Keep a log book and compare your vehicle to similar vehicles to see if the incidence of problems is reduced. These are long term tests usually stretching over many years.
The type of measurements you undertake can reflect the kinds of problems you encounter and the type of engine you are treating. This list is there only as a starting point. Make sure you give the treatment enough time to work before testing.
Permanent thermocouples are a lot more accurate because the point at which the temperature is measured can not change (small changes in location can result in big changes in temperature) and you will get constant readings (less prone to fluctuation).
N.B. Testing temperature is usually only possible on air cooled engines (or engines without a thermostat). On a water cooled engine the thermostat will work to keep the temperature constant. Thus car temperature gauges will usually not tell you if the temperature has dropped.
Air cooled engines have the greatest potential for a reduction in temperature because their oil temperature (130˚C - 160˚C or more) normally runs much hotter than the oil temperature of water cooled engines (~80 - 100˚C).
Remember to keep all variables constant:
Temperature testing is often very hard to carry out due to variations in atmospheric Temperature (T) and Pressure (P). Atmospheric Temperature and Pressure (ATP) can change very rapidly and your engine temperature fluctuates when they do. Even small changes can have quite marked effects. Air cooled engines are the most susceptible to these effects as they rely on ATP for cooling.
Try running an air cooled engine in one place to get a static reading and see how the temperature rises if you idle it for too long.