Fully Synthetic Oil Verses Mineral Oil?

[MonsterMadMarty]

I've always used Shell Advance Ultra 4 10W-40 fully synthetic oil and I buy it in 20 litre drums (to save a few dollars!). Recently I rebuilt the engine in my '93 M900 replacing the pistons and rings, the JE Pistons I used stated not to use synthetic oil during the running in process. So I've used the Shell Advance AX5 15W-50 mineral oil. 

With six Monsters in my collection and my obsessive nature I like to change the oil and filters every three months regardless. So, my questions:


Is fully synthetic oil necessary when the oil is changed on a regular basis and the bikes are never ridden hard?

Will the AX5 do the job, or will saving a few bucks now cost me long term in regards to engine life?


Cheers in advance,
Marty 

[brad black]

every 3 months?  man, you're nuts.

[Yogi]

Is fully synthetic oil necessary when the oil is changed on a regular basis and the bikes are never ridden hard?

Marty 

One of the advantages of modern REAL fully synthetics is that they can be used for extended periods of time, some Turbo cars run two years before oil change as recommended by the manufacturer. There is an article all about oil in the Tech section.
I personally think 3 months is too soon and I wouldn't waste synthetic oil by changing it every three months. You have to take into consideration advancements in oil technology since your bike was produced and what the manufacturer recommended then. I remember when I was a franchise car mechanic 20 years ago everything had an oil change at six months regardless of mileage.

[MonsterMadMarty]

20 years ago everything had an oil change at six months regardless of mileage.

I think the theory 20 years go was that mineral oil started to break down after six months of use.  An old aircraft mechanic got me into the habit of changing oil more often than recommended, straining the old oil through a paper filter and cutting the oil filter open to inspect.  I understand oil technology has come a long way but I do like the idea of screening the oil and filter on a regular basis to give me a better picture of engine wear!

And yes, I'm nuts! 

[ducpainter]

Change whenever you want...at 3 months you need serious help.

Don't let them sit with old oil. Not because of breakdown, but because of contaminants that can damage bearings,

[the_Journeyman]

One of the advantages of modern REAL fully synthetics is that they can be used for extended periods of time, some Turbo cars run two years before oil change as recommended by the manufacturer.

Example - VW TDIs have a 10,000 mile service interval for oil & filter.

I use Delvac in my Monster and change it every 5,000.

JM