question about oil & sending sample to lab for analysis
 

I've done oil searches here & elsewhere but honestly after a few dozen pages or so I feel like a Neanderthal stuck in the tar pits. I have a couple questions & I'll try to be as specific as possible.

My car is a '04 S with 89,000 mi. has an LN engineering IMS bearing.
It will be a fair weather driver (above 50 degrees f, but mostly summer warm to hot weather driving), garage kept & stored over winters in the Chicago area.

1.
I am changing the oil tomorrow & was going to use 0w 40. Is this the best weight oil for my car & area? If not what would be the ideal weight?

2.
Later this summer I am planning to to the underdrive pulley mod, does this change my oil preference?

3.
I have a test kit to send a sample to blackstone for analysis is it better to do that now, the car is new to me & the last oil change that I see in the records was done 7,000 miles ago but in 2014! Or should I get rid of that old oil & send a sample in in fall when I change it again before winter storage.

Thanks

One man's opinion; use the 0/40, especially for your cold area. In the really hot S/W (over 100) you could use 5/40. All the under-drive pulley does is slow down the aux rotational speed of the water pump, alternator and the A/C compressor. The idea being that it frees up some HP and lengthens the life of the aux. This really helps if you are always pedaling at or near red-line all of the time. And same oil either way. I would run the oil sample to get a base line. Your report will measure the solids which is what you are most worried about. Put a note in with the sample and tell them how old it is.

Send them a sample of the existing oil but change that stinky stuff before you drive it again. Clean fresh oil is always good for the engine especially after 7K mile/3 years old oil is removed. Also, cut open the old filter.

In the fall send them another sample after the driving season and compare results of the old with the new.

To me nothing feels better than revving an engine knowing you have new oil in it.

Instead of Blackstone ,consider RND .They had/have a deal offering a free expert analysis if you buy the JGDT40 from them.Maybe it expired ?? Others may know.
The other alternative is Caterpillar UOA.