What weight oil should you use in an old small block Chevy?

For older small block Chevy engines, typically produced between 1955 and 2002, the proper oil weight depends on various factors such as the engine's condition, mileage, and climate. Here are some guidelines:

1. Moderate Climate:

* Engines in good condition with less than 100,000 miles: Use a multi-grade oil like 10W-30 or 10W-40.

* Engines with higher mileage or showing some wear: Consider using a slightly thicker oil like 15W-40 or 20W-50.

2. Hot Climate:

* Newer engines or those in good condition: Use a multi-grade oil like 10W-30 or 10W-40.

* Older engines or those showing some wear: Use a thicker oil like 15W-40 or 20W-50.

3. Cold Climate:

* For extremely cold conditions: Use a multi-grade oil like 5W-20 or 5W-30 to ensure better flow at low temperatures.

Always refer to your vehicle's owner's manual for specific recommendations based on your engine specifications and operating conditions. Additionally, consult with a trusted mechanic or automotive expert if you have any concerns or questions about selecting the right oil for your old small block Chevy.