Best 4 Cycle Motor Oil?

[darwin]

Sparky with a 30 wt it takes longer to get flowing to the top of the motor and to do its job. A 10 wt will do its job a lot sooner. They say 80% of engine wear is at startup.

 

[Accender]

I belive that clean oil is good oil. 10/30 is what I use but for no crucial reason.
I changed my oil after the first 1 hour of riding on a new engine. All the machining
shavings come off in the first 30 minutes. After that I change it every 100 miles,
but Im a oil change freak. One quart = 8 oil changes. Keep it clean.

A

 

[Accender]

Sparky with a 30 wt it takes longer to get flowing to the top of the motor and to do its job. A 10 wt will do its job a lot sooner. They say 80% of engine wear is at startup.

Agreed

A

 

[Skyliner70cc]

Personally, when I see that the oil's gotten really black and it's been 3000 miles, I change it. Who cares if it's designed to last 25,000 miles. There are particles in the oil, and soot. That's abrasive. I take good care of my vehicles, car or motorized bike.

If I followed your advice, I'd be changing my oil every 5 miles in both of my diesels. That's how long it takes for the oil to turn black. The oil is designed to suspend particles, carbon in this instance, so it doesn't fall out of suspension and actually clog internal passages.

Viewing oil appearance is not a reliable means of determining usable oil life. Its almost as silly as tasting your oil to see if it is dirty.

The only reliable means of determining the useable life of your oil is to do a trend analysis using oil analysis. For vehicles, changing your oil more frequently than is required (like every 3k miles) is not only a waste of money but adds a burden on our natural resources in terms of acquiring the oil and disposing of used oil. Here is an interesting study between various synthetic oils http://neptune.spacebears.com/cars/stories/oil-life.html

As for small engines and oil changes in engines without oil filters, I'd probably do a 25 hour oil change interval. A good synthetic would probably go longer but oil analysis is not cost effective for a small engine that uses very little oil in the first place.

Notice I said hours and not mileage. Mileage is a very unreliable means of determining when to change oil in any engine. 5,000 miles cruising at 50 miles puts only 100 hours of use on a oil as opposed to a car involved in heavy stop and go driving and lots of short trips. Same goes for our MB's bikes with 4 stroke engines.

Yep, all my cars have hour meters and I keep an eye on hours in addition to mileage before I change my oil.

Mark2y, guess what? Army helicopter turbine engines do not have a specified oil change interval. Instead, oil samples are pulled at regular periods and oil is changed when lab says to do so. I've flown engines that have had the same oil in them for years.

 

[Warner]

Oil is such a hot topic. Rather than explain exactly why, I'll just say that I use the Brad Penn racing oil in my aircooled high performance car engine. (my two stroke MAB engine doesn't need engine oil) I know of extensive testing that was done that led me to the Brad Penn product. If you're interested in all the technical info (and there's a fair amount of it), I'll be happy to point you to it.

Warner

 

[Pablo]

www.bobistheoilguy.com

 

[Skyliner70cc]

www.bobistheoilguy.com

Yep, the best place to ask an oil question is not here but at BITOG.