Safe to Run??? Fuel Questions

[my69camaro]

Is used syn oil ok to run or does it need to be dyno stuff? Used tranny fluid and gear oil ok? I just wanna start burning anything I can get my hands on in my multi fuels..

Example... I have a few old chevy trucks that I'm going to scrap, if I drain all fluids (other than coolant) and mix then filter will it destroy something if I try to use it?

 

[Alredneck]

I put synthetic in mine no probs yet, gear oil needs to be thinned way down and filtered really well. Tranny fluid as in ATF filter and run. Other than than thin it down. By thinning it just use more gas. Pure oil and ATF (new ) can go right in the tank. Have fun!