Mitsubishi: Thank you and new question, overdrive switch, speed sensors


Question
Dinger,
Cain again-91 mitsu eclipse 1.8l automatic.

I wanted to thank you for all of your help. It came back to the dist.- guess thats what happens when you go to autozone... Got a new one. Runs great and so far no more dying out.

Now on to the new (easy) questions. I have an overdrive switch on the shifter. My past experiences tell me that OD is meant for 55 mph and up. However I was also told that these trannys were supposed to be in OD most all the time, doesnt make sense to me but thought I would ask to be sure, which is correct?

Second, I want to put new rims under this car. What are the max. on rim size these cars will allow, without wheel rub? And once changed, does the speedo need recalibrated for a bigger size or does the ECU take care of it?

Thanx again for all the help,
Cain  

Answer
Hi Cain,

Didn't I mention about a pick-up and you said it's part of the distributor that you already replaced??? I think I have a nomination coming on this one! I answer 20 some odd questions a day, though I remember you, I don't always remember my answer! LOL

Yes, always leave the car in OD setting. Actually, OD kicks in around 40 to 45 mph on most cars.

Tires and wheels today are crazy... You can go with a bigger or wider tire/rim, but you must keep the same height. There is no way to recalibrate the computer to one, read the right speed, but two, you have two speed sensors on the transmission and the wrong tire height will mess up shifting patterns, click on the check engine light and eventually destroy the transmission. So be careful! The ECU will cause the light to come on because it will think the transmission is slipping due to the input and output speed sensors won't match. The only way to change that is by calling NASA and have them figure out the ratio with the new tire config and have them make a pickup gear for you to put on the differential inside the transmission!

I am so glad your car is running great! Good luck Cain!