I do add a couple more PSI's per tire.. I also have been drafting the big trucks.
I've been aware of these tricks for years. Back when.. I'd draft a semi with my VW bug and almost remove my foot from the gas pedal.

It sounds feasible, but dangerous.... Looking up 'Prius recalls', the first thing I noticed was about the tires blowing out. Better to get LRR (low rolling resistance) tires to improve your mileage, and ease up on the pedal a bit. I do the 'pulse and glide' a little, speeding up to or near the speed limit, then coast a way. If I see a light ahead is red, I take my foot off the gas entirely and coast to a stop or til I need to accelerate again.

Try a more delicate or gentle touch on the gas. Stomping it only wastes gas.

You don't need to do these things all the time, just try to do them a few times, more and more. Combine trips. Drive less whenever possible. Skip the mall or movies, stay in. Telecommute or have an on-line meeting instead of flying. Don't buy polyester fabrics (besides using petroleum to make them, they are uncomfortable!)

I didn't realize a lower viscosity oil would help, I'll be doing that. I won't draft (not that there's many trucks to draft on my route) but I do coast a lot more. I use the cruise control for really long stretches though, lots of hills in my area.

Good tips, couldn't hurt to try some of them.

Every few years the RCMP are in the news, warning people about not drafting right after a messy crash that results from drafting.

Geese do it and it works for them, but the lead goose isn't a giant vehicle that might not be able to see the small guys behind it.

I've been drafting for years. One time, years ago I was in my fully loaded Tercel wagon on a 1100 mile trip. I was lucky and found a rig that didnt mind me drafting about 2 car lengths behind and I was able to draft for over 200 miles. On my next gas fill up my mileage had increased about 30% for that tank full.

Mythbusters even did a test on the drafting technique and proved that it is very effective. But they also posed the question "is saving a few $'s worth possibly losing your life?"
Wiki linky

You may be dead, but hopefully you will have saved up enough money for the funeral.

Seriously though, you should be maintaining a safe following distance.

Three seconds is cutting it close (and at that distance you cannot be drafting), however you should really maintain six seconds of distance at high speed.

With trucks, you want to make sure that they can see you in their mirrors.

"Drafting" is one of the most UNSAFE practices on the road.