Seems that things are moving well in the industry, ExxonMobil just introduced a new generation of high drain motor oils (5000, 7500 and 10000 miles) they guarantee.
Here is the link to the news:

http://www.imakenews.com/lng/e_artic...4klrks,bSW7v3P

I would say the semi blend at $2 per quart should fit Mazda requirements and protect our engines much better than the OEM oil. I am not sure if it comes as 5W20 though.

 

Problem isn't the oil wearing out so much these days...the formulations...especially the synthetics are vastly superior than in years past....it's the buildup of dirt and acids in the oil that cause the problems

My opinion....oil is cheap...change it often