Oil Question for outboard [merc]

[mr marbles]

I bought a 40 hp mercury with oil injection,the guy before me always used tcw3 2cycle injex, the only oil i could find is tcw3 2 cycle outboard oil that says it can be used in premix or variable oil injection outboards , i think its the same oil, just didnt know what variable meant? safe for all outboards merc- johnson-etc. is it safe for me to put this oil in , im pretty sure its the same stuff, any info before i put in my motor would be very appreciated,thanx!

[wishing for walleyes]

I have a 40 HP mecury 2 stroke 4 cylinder and thats what i have been using in mine and have had no problems.I have used a gallon already this year.

[boatfixer]

The "Injex" part is specific to Phillips 66 brand. The main thing to watch for is the TCW 3 rating. Personally I have switched to Amsoil on everything I own.

[boatfixer]

If you continue to use TCW 3 2 cycle oil in you 4 stroke, you will have problems! I'm hoping you meant to say 2 stroke

[wishing for walleyes]

Ooops i corrected it above

[Kyle Sandberg]

If you don't mind my asking, whats the differenc between the TCW2 and the TCW3?

[boatfixer]

TCW stands for Two Cycle Water cooled. the 2 was the old spec., and the 3 is the latest. It's the rating standard from the NMMA (National Marine Manufacture's Association)

[theoilman]

These comments may stir a bit of a debate, but here goes --

TCW3 is the latest, but I believe it is still pre 1980 (I am sure someone will correct me if I am wrong. Even the NMMA site doesn't make it clear.)- very old by today's lube standards. Most 2-cycle oil injection engine manufacturers specs use their own internal requirements rather than the very minimal TCW3, some even requiring synthetic, some requiring "ashless" - both of which are way beyond TCW3.

[mr marbles]

Is supertech[walmart] tcw3 ok for a 2 cycle oil injected merc or should i change it when the oil resvoir gets low, i dont want to wreck a good motor ' i bought a gallon of this stuff because thats what has always been in it .thanx

[theoilman]

Is the oil you have rated for oil injection? - check the label. 2-cycle oils that are designed for pre-mix only are usually the wrong viscosity for oil injection systems. Oil injection systems are very sensitive to the oil viscosity, and need to use only oils designed for oil injection systems.

[mr marbles]

Thats what has me concerned is that it says on the back of bottle can be used in premix or variable oil injected engines [water cooled] what the heck does variable mean? also can be used in other 2 cycle applications. thanx!

[Sutty]

On newer engines the mix ratio changes depending on speed or RPM. I have an opti and I think it said it makes it 50 to 1 at most but makes it 20 to 1 or something at the other end of the spectrum. I assume that is what they are talking about.

[mr marbles]

I think your right sutty,I looked again on the bottle and it said also used in variable ratio oil injection motors, it just seems strange you can also premix this also, supertech tcw3. thanx sutty! i should be safe in using this oil in my merc! good fishin!