I changed my oil as I normally do at home and the spec amount says 4.8 qt w/ filter - the oil comes in 5 qt containers - Last change it was spot on in the middle of min-max - this time it went to the max level or just a hair over - being that i added an additional 0.2 qt ( all 5 qts) - is this an issue which can cause damage - or should i drain some out ?
Thanks

 

The normal range on the dipstick is anywhere between the lower and upper line. Your oil fills will vary depending on numerous things.
The oil quantity in the service fluid capacities was derived from a new engine never having a drop of oil.
It has always been the best case to fill almost to the recommend fill and then start the engine warm it shut it off for several minutes and recheck it
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As long as you don't go below the dipstick lower line or above it you will be fine. A smidge over the top line is OK..
The issue going over the top line more concerns oil windage that could be created in the oil pan area. But the balance shaft assembly sort of prevents that anyway. I just don't want anyone to think I said it was ok to go over the top without an explanation.

IIn the Mazda's head area alone, there are several casting pools that do not fully drain that can hold oil many measurable amounts which can affect how much gets replaced during a filter and fluid service. Likewise, the pan itself can hold several once's that does not get drain either. All these and a fe more can reasonably change the oil replacement amount.
The only way way to know exactly how much to replace oil draining is to measure it and also drain and measure the oil in the filter.

 

As long as you're not deep enough that the crankshaft counterweights hit the oil in your pan, you're fine.

 

How is the OP to know how close the crank on his CX is to the oil in the pan?

 

Doesn't need to. Common sense says the tiny amount of extra oil won't be enough to cause a problem.

 

If the oil level was so full it reached the crankshaft in engines without a balance shaft it would create windage, parasitic drag on the crankshaft and foaming of the oil all would translate into a loss of power and if extreme level of oil were in the crankcase oil sump a very very very slim chance to hydro lock the respirating assembly. With a balance shaft if you over filled the Mazda by at least 2+ quarts you would hear a notable difference in the sound of the engine almost a growling sound.

 

Well for the unofficial and we will call it DIY record to fill oil above the oil pan flange it would take 1/2 quart. and to reach the crankshaft above the balance shat it would take +2 quarts over the indicated top line on the Mazda dip stick.
Don't look you will not find this information on the internet. I measured it when I had my pan off while I was designing a deep pan for my Mazda.