I just got some M1 T&S 5w40 to try in my '93 3VZ-E, replacing the M1 10w30 I've been using for the past 12K. The truck has used 10w30 for 95% of its life (short stint with 10w40), now @ 130K. I'm eager to see what happens on the short road trip coming up (6-700 miles). Previously, I'd lose about a quart per 1K during highway driving (70-80 MPH). I'm hoping this will lessen with the thicker oil.