Hi all. What is the minumum compression reading for a healthy 1990 Non-Turbo GTU Engine? In addition, the compression reading of my current engine is #1) 80 and #2) 95 How is this reading? Lastly, what is the recommended oil viscosity for the 1990 13B non-turbos?

 

85 minimum. Oil viscosity is very subjective. I use 10/40 in winter (however the car isn't driven very often) and 20/50 or 15/40 in warmer weather.