Just bought my Ram diesel (my first diesel) about a month ago (see signature for details). The dash tach shows redline at 3200 rpm. I notice that when I'm running highway speed (~70 mph) my engine speed is around 2300 rpm. That just seemed high to me. I don't know what readend gears I have. Is that in the range of what others are seeing? Any thoughts? Thanks!!

 

Look at the sticker inside the glove box it will tell you what rear-end you have.
blacksmoke

 

Ive got 4.10s in my 3500 auto. im running 315s on it now and at 70mph im pushing 1800 rpm. U prob have 3.73 or a 4.10 rear. If u want 2 drop ur rpms u need ether a gear swap or bigger tires. FYI with my 315s i still get 19mpg with my programmer all the way up and driving conservitly.

 

The RPM's sound about right with the 6 speed. What size are the tires? Mine ran at 2150 rpm at 65 mph, with the stock tires (265/70/17).

 

With that year model truck and a manual G56 tranny, you have 3.73 gears. It will be close to a truck with an auto and 4.10 gears.

 

Thanks for the replies.

No sticker in glove box... the stickers inside the driver's door doesn't give an axle ratio or axle code, etc.

As for the tires, I'm running 285/70/17, the 265/70/17 were stock on mine as well.

 

All G56 trucks in this year came with 3.73's.