[orange4boy]

After much frustration with the Previa's slushbox and the inability to P+G properly I have decided to try to bypass the ECT and put in a switch to get lockup in all gears. I live on an island with a low speed limit and steep hills so the TC almost never locks up. Im not sure how much this will help my FE but I'm determined to try it because I suspect it will. The manual transmission gives the Previa 16 mpg over the 15 the auto gets in city driving. That's 6% better and I bet it's more in hilly conditions. So if those losses are mostly the TC losses this should help. Trying to find a stickshift for the Previa is like trying to find something really hard to find: Hard. To find.

I looked into this and asked Christ some nagging questions and have decided to give it a try.

Most of the reasons for the lack of TC lockup at low speeds are about "driveability" and power. It reduces shift shock and at low engine temperatures, increases driveability. Who needs driveability? I have been told that many new Auto transmissions lock up the TC in all gears for better FE.

One question I have is about shift shock: would this damage the transmission or drivetrain? I drive pretty light on the throttle so I'm hoping this would mitigate the shock but I guess I will find out how strong the shock is if I get the bypass to work.

If so I may look at a way to apply lockup unless the transmission is shifting. this may require a skillset beyond my own if it means modifying the ECT.

I plan to set this up so when the brakes are depressed the lock disengages which is one of the ways it's controlled now.

Thoughts? Suggestions? Warnings? Colour commentary?