I searched the archives but didn't see this mentioned...so apologies if I've missed the boat!

Suppose I change my oil regularly every 3K. In that case, does it really matter whether I use regular oil such as Castrol GTX versus a synthetic blend (MC or Castrol syntec blend) for our year truck? Both Castrols purportedly meet Ford's spec. I assume 3K isn't long enough to significantly breakdown what's in the crankcase.

I still drive my old Toyota 4-banger and just passed 200K on the clock. It has never seen a drop of synthetics and compression is still up there. I don't burn much oil if any between changes. Any reason why our trucks would be so sensitive to require a synthetic blend?

The reason I ask is cuz I blindly went out and bought a box of regular 5W-20 and then realized MC oil is a blend instead.

 

no it won't matter. but the castrol tends to show higher wear metals in oua's and not very many detergents in the oil. the mc/conoco oil is good. i would use chevron 5w20 or havoline 5w20 if you can find it.