Idle at 20mph

[BrianAbington]

Theres a side road I usualy take on my way to work...minimal stops, and minimal traffic.
The speed limit is 25mph. I found yesterday that my car will hold 20mph when I take my foot off the gas. The engine drops back to idle (like Idle in drive at a stop light) It shifts to 2nd gear at about 15mph under slow accleration.

Is this a more efficent than keeping the throtle open to hold 25mph? Because the RPMS drop from like 1,500 to 800ish

[The Atomic Ass]

You'd have to test that one on your own, probably... But I can only imagine it helps.

[95badbird]

put it this way......anytime you are not touching the gas, you are using less.

[BrianAbington]

I figured that but I didn't know if vaccume pressure would affect this any.

[whokilledthejams]

An old roommate of mine had an old Chrysler M-Body with a 3-speed Torqueflite that could be coerced into idling along in 3rd, at around 25mph. Really nice in city driving.

[cfg83]

Binger -

I think you have found a comfortable sweet-spot for your Mirage. It's especially nice that the road's speed limit makes your speed look "normal". 20 MPH is probably the drop-dead-bottom-practically-idling 5th gear speed for my car too.

I wanted to find some gear ratios for your tranny, but all I could google were these URLs :

1991 Mitsubishi Mirage

Mitsubishi Mirage pictures 1991 models

CarloSW2

[BrianAbington]

theres a good sized following for these cars but most people swap 4G63T's in to them so no one knows what the stock specs are

[NeilBlanchard]

Hello,

For me, idling in 3rd or 4th gear (15-20mph) returns great mileage: 40-50mpg. Fifth gear is a little tougher to hold a speed on level ground at idle.

Throttle position is everything in FE. If I can hold the TPS to 19-20 (my xA displays 12TPS at idle when my foot is of the pedal), then my FE is much better than if it is at 21 and above.