Rpm

[Jimmy68]

Stock truck with stock tires. 01 Ram 1500 318/auto 4x4/3:55. What RPM at 60mph in O/D?
I'm running 1550RPM.

 

[usaf2006]

My 06 ram 1500, 5.7 Hemi with MDS runs about 1750 at 65-68 mph. Not the same, but gives you a rough idea. Yours seems about right as is I'd say. There's a formula, but I did bad in math in high school....

 

[Jimmy68]

My 06 ram 1500, 5.7 Hemi with MDS runs about 1750 at 65-68 mph. Not the same, but gives you a rough idea. Yours seems about right as is I'd say. There's a formula, but I did bad in math in high school....

Sorry. I'm running 33's. Want to know what stock RPM is so I know how far under it is. Speedo is 8% slow. I run by GPS so I don't speed.

 

[RonJon '06]

On stock tires you would be 1620 rpm.

 

[Jimmy68]

So going from a 245/75/16 to a 33x12.5/15 didn't change much. Bought the truck with 265/75/16 on it. Door sticker says 245. Wanted to know stock.

 

[ST-8]

I was about to say how are you going for a 16" to 15" wheel then realized you have a 2nd gen lol

I'm over 2k rpm at 60 haha

 

[Jimmy68]

I was about to say how are you going for a 16" to 15" wheel then realized you have a 2nd gen lol

I'm over 2k rpm at 60 haha

My steel wheels are off my 68 Jeepster parts truck. Written inside them is 75 International.

 

[crazy_luck]

So going from a 245/75/16 to a 33x12.5/15 didn't change much. Bought the truck with 265/75/16 on it. Door sticker says 245. Wanted to know stock.

The 265/75/16 and 245/75/16 are virtually interchangeable and run the same sidewall height (I switched back and forth on my '99 Ram all the time, depending on what was available). If you remember what the RPMs were at 60 with the 265's, it should be nearly identical to what the 245's the door sticker shows would run at 60.

 

[Jimmy68]

Ok. So I lost about 100 RPM. Thanks.

So a gear change was needed even as stock.