alfredmay wrote:
Read the article in the link below. It speaks of a never change the oil engine in a lawn mower. Mowers have no oil filters, operate in dusty conditions and are air cooled which means cooling may not be optimal. The way Briggs does this is by using automotive style engine parts and tolerances. So much for this factory feeling that acid builds up over time or the oil wears out. I don't know what they think of regarding dirt in the oil.
http://archive.jsonline.com/business/new-briggs--stratton-lawn-mower-engine-never-needs-an-oil-change-b99433283z1-290423731.html
We will see how that turns out. My gut feeling is that the increased sales from new owner perceived convenience will surpass the cost of engine replacements or dickering over warranty claims.
The rest of the article dealing with the technical changes is marketing drivel. B&S is making the same engine as they have in the past.
Changes in oil contamination or breakdown of constituents in the original oil are not all related to combustion. The oil picks up metals and materials as it runs across wear surfaces and those materials, combined with the thermal dynamics inside the engine, serve to change engine oil. Also, as viscosity additives, friction modifiers, and surfactants break down, the oil becomes less lubricant. Beyond that, oil also picks up carbon and dirt from it's daily life.
Years ago, with the advent of synthetic oils and with engineer testing, Saab released their engines touting a longer 20K mileage oil change interval. After many replacements and warranty claims, the engine warranty was extended to cover early failures because of that interval.
Although it may not be ultimately convenient, changing oil in our engines at shorter intervals, especially in the earliest years of use, will add to the longevity of the engine. If you don't care about that, extend the interval.
