is it better to go with the flow on the hwy?

[MetroMPG]

i actually do the opposite. i don't like following trucks for visibility reasons (want to see ahead as far as possible), so when i find one going the speed i want to travel at, i usually get out ahead of him by 5 or 6 seconds.

that way the truck acts as a "blocker" for faster cars coming up from behind.

my rationale: people barreling down the highway while not paying attention are much less likely to run into the back of a giant truck than into the back of a little car. i'm thinking that a big truck enters a driver's awareness sooner than a tiny car, so traffic flows more safely if it "breaks" around him rather than me.

and i don't impede the truck - i keep an eye on the mirror and if he speeds up (e.g. approaching hills), so do i.

you're probably right about getting higher mpg behind the truck though. at approximately 2 seconds and closer, the scangauge shows the benefit. you can usually tell you're getting there by a change in the sound of wind buffeting the car.