[elhigh]

When coasting to stops, leaving it in gear will increase your fuel economy.

The reason is your engine's EFI computer will detect the engine overspeeding the throttle input - that is, your engine will be revving faster than the throttle setting would indicate that it should be. Detecting this, the EFI will reduce the amount of fuel injected into the cylinders at each cycle in an effort to reduce what is perceived to be a call for reduced engine speed. On many vehicles, the resulting injector duty cycle can drop right down to 0 - no fuel gets injected at all.

It doesn't matter if your torque converter is locked or not, at this point we're only talking about what the engine is doing.

It also reduces wear on the brakes. There will be some debate, and good points to be made, that transmissions aren't for braking while brakes ARE, and while brake jobs aren't cheap they're still a hell of a lot cheaper than transmission repairs. As far as that goes, use your own judgment. My truck has 200,000 miles and I coast in gear, engine off, to stops. I only replaced the clutch this spring and am still on the original gears. How much damage that kind of use might do I cannot say but I think some of the alarmists are a bit overwrought.

NOTE: do NOT turn your engine off for coasting. You have an auto, engine-off coasting can do terrible things. Exception: if your vehicle is approved for flat towing (for instance, behind an RV with all four wheels on the ground all the time) then it's probably OK to turn your engine off, assuming you still have adequate steering and brake control. Caveat emptor!