Merimat (and others here)Frankly, I think you guys are missing the point in the discussion so far.
There is no question that oil will be needed for the next 20 years or perhaps longer so in that sense it is not a sunset industry for at least a generation and for sure long after I am dead at my ripe old age. If you are happy with minimal capital gains and dividend income then sure hang on to your SU shares.
The point is that as investors, most are looking to maximize their risk adjusted returns. This is more important the younger you are. History has shown over and over that if you invest in industries where there are in competing technologies that reduce the growth prospects of an "old school" industry, you can make more money investing in the growth industries than those that are facing limits to their growth.
Yes sometimes it will take a while for the "sunset" business to meet their doom. It took about about 25 years for that to happen to Kodak when the first digital camera was invented in 1975. But it did happen.
Back in the 70s , I invested in companies (NT to name one) that were working on a digital switch and did very well with that investment (yes - I got out before the sheet hit the fan for them on a tip from one of their engineers). Back then people people who invested in traditional hardware didn't do so well and eventually went broke if they didn't change their views. That's how the world works in a nutshell.
You guys obviously can do what you want but a word from somebody who has "been there...done that" you are barking up the wrong tree if you want to maximize your investment returns. If you are happy or just need modest returns to meet your invetment objectives then by all means stick with SU. If you want to do better than other than actively trading and succesfully playing the swings, you need to wake up or the future will pass you by.
As I mentiond in an earlier post, at my age, when I look at the world today there is very little that is left from when I was a kid. People who stuck with the stuff that is longer needed are broke!!