Unless you are sending in your oil for analysis, you are just guessing at how well your selected oil and interval are working.

You can read plugs and such, but that is like licking your finger to measure wind direction and speed, versus using a wind meter.

$20 and Blackstone (or Dyson) will tell you *everything* that is going on in your engine without actually having to pull the engine apart.

I do a UOA once a year for every vehicle I own, once their break-in period is over, and that is how I KNOW my choices for oils and change intervals are working.

Spend the $20 and get the peace of mind to know what is happening in your engine.

 

The MOCO recomends eng oil change at 5000 miles. doesn't matter whether its a softail like you have or a touring model. However the touring models have 4 qts of oil vs 3 qts in the sotails. You are putting a s__tload of miles on 3 qts of oil. Synthetic breaks down too, just not as quickly as dyno oil. No way I would risk my engine by doing servicing it that seldom.