Rpm at 50 mph

[nutpantz]

Just took my bronco 2 on the highway for the first time.
My tachometer is not reading right.
At 50 mph (80 kph) it reads either 2800 rpm or 1800 rpm...
Which one is right?

I have error code 41 coming up and I was going to replace the o2 sensor. But I drove 50 miles and only burned 5.57 liters of fuel.
Wtf... I'm not fixing anything.
I may not even replace the bald tires with millage like that.

 

[jhammel85]

1800 rpm Sounds right. My truck goes into OD between 45-50 and 50 is usually around this.

 

[kmargold]

My '02 Mazda will maintain speed at about 2000 RPM so based on my experiences I would guess the 1800