99.9 miles per gallon???

[Jeg Norge]

Originally Posted by AzNMpower32

That's because with the torque converter locked up, the engine uses no fuel. Technically the computer sees 0 l/100km, but there's no good sign for "infinite" US mpg.

As folks around here know, I use metric readings, so that means km, °C, 24 hr clock, l/100km consumption, and I ignore the mph on the speedometer. Legally, I switch over the odometer to miles once a year for the state safety inspection.

locked up? i didn't notice anything strange while driving...

[JCL]

It isn't when the torque converter is locked up, that happens both up and down hills. It is when you lift your foot off the accelerator going down a hill, and the engine is in over-run, ie turning faster than the throttle setting calls for, like when you are engine-braking down a hill. The fuel injectors shut off in that condition.

[AzNMpower32]

Originally Posted by JCL

It isn't when the torque converter is locked up, that happens both up and down hills. It is when you lift your foot off the accelerator going down a hill, and the engine is in over-run, ie turning faster than the throttle setting calls for, like when you are engine-braking down a hill. The fuel injectors shut off in that condition.

Wouldn't that apply to any time the throttle is closed and the vehicle is above ~40km/h or so? The transmission has the lock-up clutch which provides a direct connection (like an MT) beyond a certain speed. On the diesel 6AT this occurs in 2nd gear under normal circumstances.

[JCL]

Originally Posted by AzNMpower32

Wouldn't that apply to any time the throttle is closed and the vehicle is above ~40km/h or so? The transmission has the lock-up clutch which provides a direct connection (like an MT) beyond a certain speed. On the diesel 6AT this occurs in 2nd gear under normal circumstances.

Yes, it can occur any time the throttle is closed, but there is a few seconds delay, so it is seen most often going down a hill as opposed to just lifting the throttle on the flat. It just doesn't depend on the torque converter lock up, that can be open or locked. It happens all the time with our MT vehicles, and they don't have torque converters, let alone lockups.

[Penguin]

Originally Posted by JCL

Yes, it can occur any time the throttle is closed, but there is a few seconds delay, so it is seen most often going down a hill as opposed to just lifting the throttle on the flat.

Yeah, I was always surprised when I took my K75S motorcycle to ride the Colorado mountain roads rather aggressively -- I actually got better MPG than cruising across Nebraska or Kansas. Apparently I picked-up more on the downhill with the injectors turned-off that I lost on the uphill with heavy throttle.