Hi, I'm new here and picked up an 2002 ranger 2.3L auto 2wd truck for very cheap. All the filters, plugs, spark wires, and coil been replaced and soon will change all the fluids to synthetic.
I check the mpg saturday and got 24.3 doing 70-75 on the highway at 3k rps. Then sunday I got 29.5 doing about 63-65 at about 2500 rpms. To me, that means the rear-end has 4.10 gears.
My main question is, Is it normal for the 5sp auto tranny to turn 2500 rps at 65mph? And how do I know what gearing is in the rear end?
Thanks,
Roger

 

You don't just "match rpms to speed" to arrive at your rear end gear ratio.

Get down under, there's a tag on one of the rear diff bolts that has the code and it's pretty obvious, like "410" equals 4.10 gearing. Also I believe it's on the inside of your door also.

Edit: I remember years ago being in my friends Chevy 1500 and it was doing like 1000-1500? Doing 65 on the highway and I was jealous cause that is much less than my ranger

 

Thanks! I check it out after work.

 

Ford Ranger Rear Axles - The Ranger Station

 

Thanks! I got 4.10 gearing. Right on the tag.