You need a blend for typical use. The first number should be a 5W or 10W (weight) The 5W for winter starts, below 40F & the 10W for summer. The second number should be a 30W or 40W. So a 5W-30 for winter use is good, 10W-30 for moderate temperatures and average use, go to a 10W-40 for harder use (long highway runs or towing) These are typical suggestions. When you get into the 20W-50 oils, they are really thick and can damage your engine over time, mainly from the start up in cooler weather. Some people use 20W-50 to help worn piston ring problems and push the life a bit further before the engine gets tossed or rebuilt. Carburated cars usually won't start at cold temperatures without a couple of throttle pumps, so before you pump crank the engine for 10 seconds or so a couple of times, this will pump the oil up to the valve train and lube it before starting. Then pump it & start. Synthetics should only be run in late model engines or new rebuilds that can handle them - can't be mixed with conventional fosil types. Stick with a brand that works, frequent oil changes with a new filter. I'm not a mechanic, but these suggestions came from good mechanics, common sense guidelines.
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Wally
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