Shift Points

[Joe Jeep]

What controls the shift light arrow on the dash? Stict rpm or...?

On my way to work this morning I noticed the shift arrow aluminating when I was around 2000rpm. The lighted arrow on the dash was telling me to put the truck into 4th at around 30mph (~2000rpm) which seems really low for a truck only having 4 speeds.

For reference, the truck idles around ~700 to 800rpms when warm on an aftermarket tach I installed.

The reason I am wondering is because I suspect the truck runs rich, but I drive it so infrequently I don't know the average mileage (in the last 5 months I have driven it 495miles). The only time the truck went on a trip, it was pulling a empty trailer and got 20mpg and loaded with ~900lbs on the way back it got 17mpg.

[Geonovast]

at 30 I'm usually in 4th, unless I'm accelerating

 

First thing I did when I bought the truck was pulled the dash and ripped out that stupid light. Did the same thing with my 88 XJ. I was getting tired of it going off in Reverse and telling me to go into a 6th gear I didn't have.

[Pete M]

I'm convinced the shift light in my 88 is simply haunted. :D

[summerinmaine]

I'm convinced the shift light in my 88 is simply haunted. :D

 

Same here. Mine "works" erratically, and is difficult to see when it does light up, so I just ignore it.

[martywarner]

the most i can figure its a combination of vacuum pressure and rpm. Kinda like the old fuel economy gauges, all theye where was a vacuum gauge. thats what the shift light is for is economy.

marty :Canadaflag:

[Oizarod115]

i shift at 2500ish until 4th which i go into at like 35-40mph depending on acceleration, and 5th is for anything 50+

 

there ya go... ;) shift points

[Pete M]

Back when the 88 was 2wd and me DD I generally shifted around 3500-4k. :D When the Dakota became my DD I gained an extra hundred or so horses from the 360 and it only cost me an extra dollar a day in gas for a 2-3 hour commute. :roll: Fuel mileage was never really a big selling point with me. Even with the diesel Libby (where 30+mpg is not unheard of), all I really wanted was the 300 ft-lbs of torque and that glorious turbo whistle.

[JeepcoMJ]

the most i can figure its a combination of vacuum pressure and rpm. Kinda like the old fuel economy gauges, all theye where was a vacuum gauge. thats what the shift light is for is economy.

marty :Canadaflag:

 

anyone know where I could get one of them economy gauges? porsche 944 has an integrated one...but I'd like a seperate one, to see how acurate they are.

[Tracker]

anyone know where I could get one of them economy gauges?

JC Whitney has 'em.