Confused dipstick says use 10W30

"Hi again all. Went out this m

"Hi again all. Went out this morning to change the oil in 4.3 engine first time. Entire engine is brand new, not rebuilt, 20- hours, put in Feb. this year. After reading about the 30W on here, that is what I bought to use, but then see on the stick use only 10W-30? Should I use the 30W? I know most new automobile engines now use 10w-30 and run at 190-195* but a new marine engine? I know they run much much cooler but harder. I take care of my things and always use Mobile 1 10w-30 synthetic in my other vehicles with excellent results. Don't want to wear out a new engine."

"I'm running Mobil 1, 15W-

"I'm running Mobil 1, 15W-50 in My 4.3l.......

No Problems at All.......

You can run anything that's as Good, or Better than the recommended oil...."

"Thanks Bondo, sounds good to

"Thanks Bondo, sounds good to me! I've even always used 10w-40 in all my lawnmowers since the 80's! Have not had one blow up or anything yet. Personally, I have never used straight 30W in any engine."

"wait a moment. wait till the

"wait a moment. wait till the engine is broken in before running synthetic oil. could cause problems. rings dont wear in properly, and you will burn oil."

"Sure will do. Thought about t

"Sure will do. Thought about that after I got to town. (age taking a toll!) How many hours you think on a marine engine is good before I switch to synthetic? Think for the first time, will use the 30W like everyone else until the rings seat good. Don't like the 10w-30 dipstick idea."

"What does the owners manual s

"What does the owners manual say? Most manufacturers recommend straight 30W. I guess because the marine engine is always under load and 30W thicker. Probably doesn't breakdown. Synthetics are good but personally I don't see the point. Maybe if I had a racing engine worth some big bucks. Here is the problem. Oil gets dirty, synthetics get just as dirty as petroleum oils. Dirt causes wear. So why get a synthetic when it needs to be changed every 3000 miles or 3 months? It may last for 10K miles without breaking down but it's going to be black as tar. You really shouldn't be going 7-10K miles between oil changes. I guess you could just change the filter on an engine that was running synthetic oil. I change my oil on the boat every 50 hours and use good ol Super Tech 30W from wal-mart. I have for years and never have had a problem. Even use their filters and throw in a can of good ol STP oil treatment. Have close to 900 hours on my 5.7L it doesn't smoke. Took the valve cover off and its clean as can be, no sludge. OK, lemme get my bullet proof vest on...."

"Owners manual says 30W, but t

"Owners manual says 30W, but that is for a 1987 engine and this engine is a new 2007 and dip stick says 10W-30. That is why I was weary. Anyway, put in 30W and will run it until I think the engine is broke in enough and switch to the 15w-50 like Bondo. Maybe at least 30 hours should do it on a marine engine being it runs at high rpm's and a strain all the time. In a car says don't use synthetic until after at least 200 miles on a new engine. I have been using synthetic oil a long time and have excellent results with it. I use synthetic in a 1993 ford F250 4x4 super cab (10W-30), 351 gas engine, 181,000 miles, no ticks, no oil burning, no oil leaks, still as strong as day I bought it! Also a 2000 police interceptor I got in 2000 when in police school and still drive it, it has 91,000 miles now and same results. Better gas mileage, more hp, easier starting, and engine stays much cooler in hot weather temperatures but still change oil and filter every 3,000 miles. It comes out tan but not black like when I used regular oil. It is worth to me a little extra money to pay for synthetic as I am sure I get some back with the gas mileage. Everyone has there own opinions and all the oil now is good. I just seen the difference and will stick with my Mobil synthetic! Happy boating!"