best grade of oil to use in 1993 camaro

No one can tell you what oil to use without know about you, your car and your plans. Everything you ever wanted to know about oil and more - http://www.bobistheoilguy.com/motor-oil-101/

What does your vehicle manufacturer recommend? High mileage? Go to a 20W40? Cold weather, 10W30. Hot weather? Try either a straight 30 or 40 weight. Using oil? 40 weight and save for an overhaul. Any known brand is a good use. If you race it, racing 50 weight. If it is a work pick-up, use a higher weight oil. Like "tenspeed" said, we need info to give advice.

it will depend on the climate where you will be operating the vehicle, what you plan on doing with the vehicle ie drag racing or normal driving, and the milage on the engine the more miles the higher the viscosity such as under 100k you'll want closer to manufacturer recommended.

I use 10-40w on my 94 Z28.......Ive used Royal Purple and Mobil 1..............never had an internal engine problem .....way over 100k miles

yeah I used 10w30 on my intrepid in the winter and 10w40 in the summer and I never had a single problem