46RH overdrive ratio.

Thank you for that. Sorry if my lack of understanding is frustrating but I'm finding it hard to work this out.
Please try to be patient.

Amongst other things I'm trying to work out the speeds to switch in overdrive and lockup automatically. In the above example it looks as though switching in overdrive without lockup introduces a load more slip that would generate loads of heat in the transmission fluid and harm gas mileage.

This leads to questions about stall speed and slippage below that speed - and I got some very sarcastic answers when I last asked about that. it's pretty frustrating as we all have to start somewhere. My area of expertise is electrical systems. I have seen what seem to be some very dumb questions asked on forums that I have answered patiently and I think I have really helped people.