at 70mph it would save gas I would think? it would be around 600rpm less than doing 70 with say 4.56 gears unless the engine doesnt have the power to hold speedat 1500-1600 rpm and downshifts out of od (very possible) but even then drive would be close rpms to proper gearing with OD on so...... I would think city driving is where you would dump a lot of mpg as the od wouldnt even kick on in normal city driving...and your alway accelerating.

 

well, a simple test would be to find someone with stock tires (245 70) and borrow them for about a half a tank to check the mileage.

 

Ok. So i went ahead and changed oil, and went to do the spark plugs. I got 6 of them changed but on the other 2 the metal protective casing around the spark plug hole was bent in at the bottom. I wasnt able to get them out. Anyone else have this problem? If so, how did you get it out?

 

the sheilds are threaded into the spark plugs holes so they will not pull out. they need to be twisted out. but they are probably rusty so you're gunna bend the $h!t out of them

 

mine aren't threaded. i pull the back two on each side out with a pair of channel locks whenever i mess with the plugs (or needle nose pliers depending on which one it is) and they just slide right out. mine are lubed up with oil though from the valve cover leak that i used to have.

put a hefty hose clamp on the base of the heat shield and try to compress it with that to see if you can break them free. the first time i pulled mine off i had to grab the base of them with the channel locks and close the gap to break them free.

 

I get around 320 miles to a tank, 80%highway 20% city, 2001 quad 4x4 318, 245 stock tires. I think I do well compared to what I see some on here getting. Mine when I checked, was about 16mpg.

 

what is a tank to you? a tank to me takes about 23 gallons to fill up.
when i first got my truck i used to go about 320-330 miles before i filled up and put about 23 gallons in it. right now it isn't even close to that though, i need some 4.10 gears bad.

 

Tank is about 20.5 gallon.

 

Not really. I've seen tests that show that above 60mph the increased wind resistance and higher rpm hurts mileage more.