> I HAVE A 79 280ZX WITH 100,000 MILES ON IT
> WHAT WEIGHT OIL SHOULD I USE? EVERY THING IS
Unless you are burning more than a quart/3,000 miles I'd stick with the recommendation in your owners manual. In Texas I run 10W-40 in the winter and 20W-50 in the summer in my '77 with 165,000 miles. Your owners manual should have a chart in it that recommends different weights for different temperature ranges and driving.