There are a few special problem areas for motorcycle oil. Most motorcycles have wet clutches, which means the motor oil runs through the clutch. If the motor oil has too much molybdenum in it, there are fears that the clutch can start slipping. No one I know has ever actually had this happen to them, but the warnings are all over your owners' manual and the oil companies' web pages. On the back of all certified oil cans is a circular stamp with the certification. Avoid oils that say "energy conserving" in the bottom half of the donut. These oils contain friction modifier additives that could cause clutch slipping over time. Essentially all 0w-20, 5w-30 and 10w-30 oils are energy conserving, and should not be used in your motorcycle.
Most motorcycles run the engine oil through the transmission, and the transmission gears are very hard on the oil's VII package. This means that over a couple thousand miles, the oil's viscosity can break down. Standard car oils are only good for typically 1500 miles before they've lost about half of their viscosity. Remember, 10w-40 oils contain a lot of VIIs which tend to shear in your transmission, so I believe 10w-40 oils should be avoided. You can't use 10w-30 because of the friction modifiers. This doesn't leave much. Commercial 15w-40 oils are a good choice, because they have relatively few VIIs which are the more expensive shear-stable sort. Synthetics typically don't contain much of a VII package, so shear is not as big an issue with them.
Some people use their motorcycles only sporadically. This means the oil can all drain completely into the sump, leaving no protective film on the bearings. The first start after a long period of non-use can be particularly hard on an engine. Film strength is very important if you're a sporadic rider.
There are several key advantages to using Synthetic Oils:
Synthetic oils have a higher viscosity index than mineral base oils. Synthetics have better resistance to thinning at high temperatures and thickening at low temperatures. Since synthetics have little or no VIIs, synthetics last longer in service without radical changes in viscosity.
Synthetics have a much higher film strength than petroleum oils, so it takes a lot longer for the oil to drain completely off your bearings and into your sump.
Diester synthetics are polar molecules with solvent properties which dissolve residues and combustion byproducts.
Three synthetics stand out from the rest: Mobil Delvac 1, Mobil-1 SUV and Shell Rotella T Synthetic. These are C certified industrial oils meant to be purchased in 55 gallon drums and used by companies which run a lot of diesel engines. The Commercial oils, have more expensive additive packages which are meant to prolong engine life and oil life, as opposed to being cheap to buy at Pep Boys and helping the car companies meet their CAFE requirements. These oils meet all the automobile requirements through SJ, and also have extra additives to help pick up gunk in the engine, to keep the oil from becoming acidic, and to maintain the oil's viscosity over a long time. In fact, the manufacturers talk about their oil's viscosity resistance to shear forces - exactly what a motorcycle needs. Shell Rotella-T Synthetic is available at Wal-Mart for $13 / gallon, so I consider this the motor oil of choice. Delvac-1 is very hard to get in the west - there are only two places in all of California where you can buy it. Mobil-1 SUV is readily available everywhere for about $4.50 / quart. When used with the correct filters, these oils are certified for 50,000 mile oil change intervals, and are frequently used for 100,000 to 150,000 miles in diesel long-haul trucks. Now, before you get all excited about the possibilities, you must also keep in mind that the diesel engines don't run their oil through their transmission, and the large diesels all have two oil filters, one a normal paper filter, and the other a 1 or 2 micron filter that catches pretty much everything. We don't have these secondary ultra-fine oil filters on our bikes. Also, the large diesel engines hold eleven gallons of oil - a oil and filter change costs these guys $350 if they use synthetics, $150 if they don't.
http://motorcycleinfo.calsci.com/Oils1.html
oil in various brands, mostly synthetic, and once or twice dino oil. I now have over 80,000 miles on my Voyager, and I have never had any clutch slippage using these oils. I have found that most that did have clutch slippage problems, were because of other causes not associated with the type of oil they run. Back in the 70's, it was a known that wet clutches with all metal plates were more susceptible to clutch slippage because of using additives like STP. At that time, it was said that clutches with both metal and fiber plates (like most wet clutches today) were not affected by these additives like the all metal clutches were. I do feel that synthetic is the way to go for my Voyager and at present, the Mobil 1 seems to work a little better than some other synthetics I used. Just my opinion. If you want to spend more, then use the motorcycle specific, for me, the synthetic car oils seem to work fine.
you did good with one exception, you shouldn't have told the wife what happened to her measuring cup! 
