Oil type for 1991 Silverado
Best oil? She has 269747 Miles under her
10W-30 is the recommended oil. High mileage oil would be a plus
The same oil you have been using all these years. Go a step up in weight if you are leaking out the gaskets.
Exactly, my 03 S10 Pick Up has 296,000 miles on it and I still use the recommended 5W30 with no problem. Hope that helps! Jim