I know I can stop faster than an 18 wheeler but I don't like driving behind a vehicle I can't see through or around. I also don't like the idea of have a 100 lb tread thrown at my windshield unexpectedly.

Interestingly, Mythbusters did a pretty good test on drafting and proved that it increased mileage until you got to a certain point at which point it became more difficult to maintain the spacing so he was using more gas.

I've also heard that truckers will get PISSED if they know you're back there. I would be too considering that they are paying for the increase in your mileage. Nothing comes for free in physics.

 

It also breaks my heart with every little rock I hear coming in contact with my paint.

 

Apparently the lights are only on the moon roof version, which I don't have.

 

ah ha!

that is odd

 

Found it in the manual

 

probably cause there isn't really any room for them in the typical place in middle of the roof in the moonroof version.

but my envoy had an entire dvd console in that spot?

I dunno?!

 

'twould make sense, were it not for the fact that the non-moon roof lights are near the front.
The front personal lights wouldn't illuminate any reading material for a back seat passenger.
I guess they think people without moon roofs prefer it dark??

 

Well, some do, and some don't. Some don't mind as long as they know you are back ther, and some hate it.

I have found that you can follow at a safe distance and get a slight mileage increase if you happen to be in the right place at the right time. This means not chassing a truck so you can draft it, but if a truck is going the same speed you want to go and you are close I don't see a reason to not use a bit of their wake to shield your car.

And for the physics, you are not increasing the drag on their vehicle, so their mileage will not decrease, so yes you are getting something for nothing.