Tue Aug 10, 2004 7:07 pm

Rudi wrote:1. Why should anyone put synthetics in the Cub?
Rudi, I can't speak for anyone else, but my 48 was developing low oil pressure (6 pounds) when hot and at idle. Oil useage was minimal, but it was overhauled 17+ years ago. Going to a 20w50 blended is keeping the oil pressure at about 12 pounds when hot at an idle. I apparently need crank bearings, but that is a project that is going to have to wait a while. Missy is now doing the hard work, so the 48 can take it easy for a while.

Tue Aug 10, 2004 7:18 pm

1. Why should anyone put synthetics in the Cub?

I did and it makes my oil pressure guage look better after running C2 mower 3 hours at full throttle.

Tue Aug 10, 2004 7:30 pm

Historically, conventional oils lack the performance of synthetic oils in the areas of low-temperature performance and high-temperature oxidation stability. Conventional motor oil is made up of an inconsistent mixture of long and short chains of carbon and hydrogen atoms. In the extreme heat of an engine, short-chain molecules can evaporate, and unstable molecules can oxidize and break down. Conventional oils also contain much greater amounts of impurities, such as sulfur, reactive and unstable hydrocarbons, and other undesirable contaminants that cannot be completely removed by conventional refining of crude oil.


Tue Aug 10, 2004 7:33 pm

Yep, basically the synthetic oil will maintain its viscosity across a broader range of temperatures, hence the ability to start easier when it's cold (conventional oil would be gelled), and hence the ability to maintain higher oil pressures when hot (conventional oil would get very thin.)

Tue Aug 10, 2004 8:43 pm

There is no doubt that when it comes to oils, there arguements from East to west and north to south. So just to put my 2cents in , I beleive you have to compair apples to apples. If you put the cheepest non deturgent oil in your cub at say 30w. and then change it to 50w. Your oil presure is going to almost dubble. Your pushing a heavier voscity product through the same size hole .However modern tecnoligy takes the back seat to nothing. Synthetic oil is top shelf. "Jack" :wink:

Thu Aug 12, 2004 12:05 am

OK... I'm sold.

Should I do anything to flush out the system before changing to the synthetic? My old cubs have been running low ash non detergent oil. I assume that synthetics are high detergent oils :?:



Thu Aug 12, 2004 8:02 am