For most vehicle max economy occurs at the  lowest speed you can travel in the highest gear you have without lugging the engine. Air resistance is the load. As the Vanagon auto does not have a locking torque converter there is the variable of slip which is massive at lower speeds, especially under 1,800 rpm, the stall speed. So probably somewhere around 30-35 mph is best. Over 55 air resistance goes up exponentially and so will horsepower required. There was a reason that was once set as a national speed limit. 

Dennis

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of Jeff Palmer
Sent: Sunday, May 19, 2019 10:36 AM
To: vanagon@GERRY.VANAGON.COM
Subject: So what�s the most efficient speed to cruise at?

2.1 auto. Curious!
Jeff

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