I'm changing over to Mobil 1 synth 75w90 LS in transaxle/diff (4x4) along with 1 oz per qt Tufoil.
Going with Mobil 1...0W30 synth oil in the engine (+ 1 oz Tufoil / qt) along with a Pure One PL30001 "Mustang" oil filter on a 1.5L engine. Oil can be found at Walmart for $23/5 qts.
Can see why I never did this before...since the almost 6 quarts of gear oil needed can be had for around $20 in dino...and around $60 in synth...and this isn't Redline or Amsoil. But it's good for 30K...so an extra $12 a yr.
I use the filter on the right....the one on the left is typical for the 3AC engine....
Intend to run the motor oil for 12K...with a filter change at 6 months. Hopefully no more than 3 extra top up and filter quarts will be needed over 1 yr.
Might change my user name to Slick.