To my knowledge, the short answer is no. Red and silver may hybridize, but not sugar maple with the other two.

Ditto............it is unheard of. The red/silver cross saccharum alludes to is the well-known hybrid Acer freemanii, of which "Autumn Blaze" is a well-known cultivar.

Sugar and silver are too dissimilar to yield an interspecific cross.

+oM

Two different sections of the acer genus. I don't know if species from different sections can cross but it is at least much less likely.

How about blooming time, does it occur simultaneously for these two species?

Around here, reds and silvers bloom anywhere from late Feb through mid March, and Sugars usually not until about early to mid-April.

You know there are techniques available where a cell from Sugar Maple could be fused with a cell of Silver Maple. Assuming these cells would be viable, it would be interesting to see what would result. Potentially you could end up with a very fast growing tree that is also very tough. Have 4 or more complete sets of chromosomes often result in very vigorous plants. Many of our crop plants have 8 or even more sets of chromosomes. Then there is the potential of hybrid vigor. The issue would be getting someone to pay for the lab work, then tissue culture work with no certainties. And for those of you who get uncomfortable with the ideal of combining species, it happens every day. The freemanii Maple is a excellent example. Venus Dogwood is another, along with the Stellar series. Then there are all the crop plants......

Arktrees

My neighbor has a large maple with thick leaves that look like the sugar maple. It releases it's samarras in late summer/fall. It is not a small maple, it is as big as any red/sugar maple, if not for the seed drop time near fall, I would think it was a sugar maple, it has great yellow fall color, so it isn't red maple and I know 100% sure it's no crappy sugar maple. I've wondered this for the past 4-5 years, but just now am asking.