can older tcw-2 oil be mixed with tcw-3 oil?

[indyboy]

Thankfully I didn't do this myself but I have a friend that has a 1957 3 hp Sea King that calls for 24 to 1 fuel/oil ratio. He bought fresh 93 octane gas today and used some 20 year old tcw-2 oil and the other half of the oil was new tcw-3....Can that be safe????

 

[jimmbo]

If the old oil had not been opened and exposed to air, it shouldn't be a problem. Would I have done it? No

 

[indyboy]

Thanks for your input.....I think the old oil was a new can but why risk it? If anyone has info or horror stories tonight that would be great because i am meeting up with this motor owner tomorrow... I need ammo!

 

[flyingscott]

Ammo for what the motor was designed to run on 30 weight and tcw-2 is better than that. The 93 octane was a little overkill

 

[indyboy]

initially the owners manual recommended a 16 to 1 ratio with 30 weight oil but that was quickly updated to a 24 to 1 ratio with better oil. I'm sure using any current modern tcw-3 oil. i assume 24 to 1 is enough. let me know if you have a different opinion

 

[F_R]

TC-W2 formed more carbon than TC-W3, but I doubt you are going to be running on it long enough for that to be a concern. I'd run it without a second thought (yes and mix them). The difference between 16:1 and 24:1 is only a couple ounces per gallon. Considering how long a gallon will run it, those 2 oz are the proverbial drop in the bucket.

 

[ondarvr]

Oil oxidizes over time and becomes less efficient, while some oil companies show shelf lives of 4-5 years, or maybe a bit more, 20 is way too old, plus it's an older formula to start with. On the other hand the motor used a less refined non 2 stroke specific oil to start with. Would I use it...no...will it cause any harm...probably short term use wouldn't make that much of a difference, especially if it was blended with a more current product.

Forget the 93 octane, it's of no value in this motor.

 

[indyboy]

Thank you all for your input. :joyous: