Wanted to get some ideas on what engine oil to use. I have older tractors that I farm with,1466 international and old two cylinder John Deer. I like to use 30wt I can get Shaeffer 7000 para synthetic for $23 a gallon from a rep or get rotella t1 from tsc for $14 gallon. I usually change once a year because I put around a 100 hours a year on them. I don’t mind spending more if it will actually make the engine last longer but don’t want to waste money either.Thanks