There is little to be gained in pulling the front shaft. The live front axle turns all the time, so in reality, the only thing you're saving is the *slight* resistance put up by the U-joint and CV-joint on the front driveshaft (and they're not running at much of an angle to start with). As already mentioned, you cannot remove the outer CV joint as it holds the hub together.
I recently began getting better mileage on my daily 40 mile commutes to and from work. I went from 15-17 to a consistent 20-22 mpg by doing two things and two things only:
1) Instead of setting the cruise control at 75 like I've done for the last 3 1/2 years, I set the cruise between 62 and 65.
2) Draft a semi when I can. I cruise around 60 in the right lane until a semi passes me. then I bump the cruise up to 62-65 to match the semi's speed (leaving adequate space to stop and so I can be seen in his mirrors, of course).
Those two changes alone have upped my mileage for the last four tanks of gas to between 20.5 and 22 mpg (and that's with the AC running most of the time). I'm still filling up at the same exact fuel station I have used for the last decade, and made a conscious effort to make my driving style the only thing I changed. So far, I'm quite happy with the results!
Here's some food for thought... On a 6000 mile trip, the difference in speeds means it would take 100 hrs at 60 mph, versus 80 hrs at 75 mph.
Now, lets say that running at 60 mph, you can get 21mpg, and at 75 mph, you get 17mpg. Figuring an average of $4.25/gallon, that 6000 mile trip will cost $1214.29 in gas at 60mph, but $1500 on gas at 75mph. That's a fuel savings of $285.72
Given those numbers, in my book, run 75mph. If you run 60, that extra 20 hours likely means one more night in a hotel, plus two or three more meals on the road, which will eat up a good chunk of that fuel savings, and it'll take an extra day. Running faster saves you a day on the road, a night in a hotel, and a couple of meals... IMHO, it's worth the trade-off.
I was bored at work this morning... Sorry if I added to the confusion.
-Joe
