There is about a 10% reserve built in.

 

Still probably isnt great pulling remnant fuel off the bottom of the tank...but I dont know.

 

Probably not the best, but if you have a clean tank shouldn't hurt... I have done it 3 or 4 times on these filters and have 29K miles on them with only a .5psi difference from new.

 

I try to not let my tank get below 1/2 in the winter or 1/3 in the summer as you never know when an emergency will come up. In an emergency you don't have time to stop to get more fuel to get to where ever. Also in the wintertime where I live you could get caught in a snow storm and may need a lot of fuel to keep warm & alive!

I just put on 4 new Cooper STT's and saw my mpg drop just 1.26 mpg and the tank was about 3/4 full when I put them on so I think I'll see a loss of 3 mpg while I have them on this winter. But then I also have a lot more traction then the all most useless factory Michelin A/S tires in the snow or on wet grass.

 

All good points and it's alot easier to stomach a fill from 1/2 then E...Hope those tires work out for you, I cant get out of the pasture when it's wet without 4x4

 

Not a problem, your fuel is picked up from the very bottom of the tank anyway. You want all the stuff that settles on the bottom to end up in your filter. The only thing that is not good for it is the heat not being disipated from hot fuel coming from the CP3. Your fuel pump will run hotter, since it is cooled by the fuel volume.