Alcor TCP Fuel Treatment FAQ & Tips

If a little bit of TCP is good, is some extra a little better?

Definitely, NO. The effectiveness of TCP is maximum at the concentration specified and any increase or decrease reduces its effectiveness as per the following chart:

How well does TCP mix with the gasoline in your tank?

This is a question that is often asked. To answer this question, ALCOR conducted two flight tests using a Cherokee 235 and the phosphorus content of the fuel going to the engine was measured to establish phosphorus content versus time.

For TEST A, the Alcor TCP was added before filling the tank, which was 15% full of untreated fuel. In both cases, the time between adding the TCP and take-off was kept to a minimum, twelve minutes for TEST A and ten minutes for TEST B. The following results were obtained, which indicate that the initial higher concentration following treatment is normalized within only a few minutes.

If the airplane had been allowed to sit overnight, the initial increased concentration of TCP would have been considerably reduced based on laboratory tests. So if one forgets to add the TCP before filling his gas tank, it can be injected afterward without too much initial increased concentration of TCP.

If I accidentally put in too much TCP, say treat it twice, what harm might I do to my engine?

No data exists from aircraft engines to answer this question; however, a 70% increase in exhaust valve life was experienced in automotive engine tests with double the concentration of TCP specified by ALCOR. These data were published by The Ethyl Corporation.

Will TCP benefit engines rated on grade 100/130 octane fuel the same as engines rated on 80/87?

Definitely, yes, by reducing spark plug fouling. Controlled tests conducted in two Barons showed that the time between plug changes could be tripled by using ALCOR TCP Concentrate. If such an improvement justifies the cost of TCP treatment, one cent per gallon, then TCP is a real benefit.

Should TCP be added to Grade 80/87 fuel?

Yes, to obtain maximum results, because 80/87 contains one-fourth the lead content of LL100. If you are using TCP-treated LL100 and you add 20 gallons of 80/87, then add one-fourth the TCP concentrate you would add for LL100; i.e., that for 5 gallons.

Does TCP affect any property of the fuel such as octane rating?

No, it should therefore be used in 100 octane rated engines utilizing 100 octane fuel if lead fouling problems exist.

Why isn't TCP approved for turbocharged engines?

TCP has not been approved for turbocharged engines because earlier testing gave excessive turbocharger deposits in a particular engine. No data is available as yet concerning whether TCP will cause deposit problems with present-day trubochargers.

What is the suggested method for adding TCP to bulk storage tanks?

For fleet operators where bulk fuel storage tanks are available that can be dedicated to servicing non-turbocharged aircraft only, it is practical to treat bulk fuel. Otherwise it is suggested that TCP be put into the individual aircraft fuel tank at the time of servicing. TCP treatment of fuel should be according to the quantity and type of fuel added, as specified in the blending table on every label of TCP cans. To simplify treatment, a dispenser kit is available from ALCOR.

How much AvGas will a gallon of TCP Concentrate treat?

4960 gallons Grade 80/87, 1240 gallons LL100/130, 640 gallons regular 100/130 (4.0 ml TEL/GAL)