I owned a TNT 3 for many years and used 30 weight motor oil which VPI approved. In my new VPI Prime Signature 21, I used 30 weight synthetic motor oil and VPI said that's good.
Part of the reason I buy VPI is because they are so well made I don't need to worry a lot. But I'm not a guy who would pull apart my turntable, which sounds like fun, but i'm getting a bit old for that.
Once my roof leaked during a rain right on top of my TNT 3. In that case, I sent it back to VPI. When they sent it back to me, they told me to oil the turntable with 30 weight motor oil. One can will last many lifetimes.
I used to have the JMW Memorial 12" uni-pivot arm. They told me to use a lighter oil on that, but I purchased my new turntable with the gimbal arm, so no more worries about that, I think. Unless the gimbal arm needs oiling. I haven't thought of that until now. I'll contact VPI.