dino oil vs synthetic mpg

ktmrfs wrote:

FishOnOne wrote:

soren wrote:

Cummins12V98 wrote:
"I have been using synthetic oil since 1974...."

Same here, my Dad was the first Dealer in WA. I have never bought AMZ/OIL for mileage increase but I am sure it does help "some". You can thank this company for pushing the others towards Synthetics.

In the late '70s I was a high school kid, working part time at a small engine shop. We had a valuable commercial customer who became enamored with the idea of using synthetic in his mowers. The head mechanic was not impressed, so the customer told him he could prove it was better. The mechanic started a commercial two cycle push mower, and checked the RPMs on idle. They drained the dino oil out of it, refilled with the synthetic and started again. The idle was roughly 500 RPMs faster. All of us were pretty amazed. I'm sure that this trick would be tough to repeat, given that two cycle mowers are gone, and I'm sure dino is a far better product that it was in 1978.

I'm confused.... You said they drained the dino oil and refilled with synthetic on a (key word coming up) 2-Stroke engine.

In the case of many two stroke gas engines, oil injection was very common. fill a tank with oil, and a pump injected oil to the crank at anywhere from 200:1 to about 20:1 depending on load. so he may have been draining the injection pump sump, thinking it was the engine sump.

now 500 rpm increase??? that sounds far fetched. 50rpm maybe.

this is still common in jet ski's and I believe outboard motors. seems like motorcycles and lawn mowers have gone away from oil injection back to std 50:1 mix.

two stroke does NOT mean you will always have a fuel/oil mix. In fact AFAIK ALL two stroke diesels have a seperate sump and use a supercharger for intake air. crankcase is seperated from intake/exhaust path just like in a 4 stroke. the same can be done on a two stroke gas engine, but seldom has been done.