2400 rpm at 75mph... is this normal???

[dehdlee Duo]

Hey all haven't posted in a while but wanted to find out what to do.

I have a 99 Ram 2500 cummins 5spd, running stock 3.55 gears with 285 75 16 tires. The stock tires are 245 75 16's. When driving on hwy at 70-75 I am still getting 14-16 mpg but my rpms are like 2400. Is this ok to run? I plan on not going any higher than 70 in this truck. We are also looking for a trailer to tow with for trips.

Would it be a good idea to get near gearing? I have heard if I went to 4.10's it would make my rpm's jump. What is a good idea? I am stuck...

Thank you all in advanced for information.

 

[gtomike60]

If you go to a 4:10 gear,your rpms will be higher than with the 3:55s you have now
You need a taller gear(numerically lower) to drop rpms
A taller tire will lower your rpms if there's room for them

 

[dehdlee Duo]

If you go to a 4:10 gear,your rpms will be higher than with the 3:55s you have now
You need a taller gear(numerically lower) to drop rpms
A taller tire will lower your rpms if there's room for them

So would it be good to go with a 4:10 and a 35 inch tire for towing? I want to keep my current tire setup since it is perfect for how I want it to look. I am not wanting to spend more money if I don't absolutly have to. I am working on getting a chip so I can use towing options and better performance so I am not worried about gearing since it is a big job.

I will be getting an exhaust and Fass fuel system to help with those pesky gen 2 issues.

 

[PaPitt]

What issues are you talking about on the Gen 2's ..
Pesky issues ..
I'm going to say GEN2'S DON'T HAVE ISSUES .
i WORKED FOR A DODGE Dealership for 11 years back in the service dept.
Now the dodge 2005's up until about 2010 sure had bad nasty issues.. Fuel systems killing motors . Is that the issues your talking about .
........ But the loud diesels motor didn't have the fuel issues. It was after the Quiet motors came out .

 

[Rob2gen]

Long time ago my 98.5 2500 12 valve 4x4 Auto reg cab (bought new) had top speed of 82mph with OEM tires and chrome rims... had 4.10 gearing and got about 17mpg, mostly highway miles. Trying to remember the rpm's for that speed but 2800 comes to mind. Switched over to a 33 inch mud tire and Eagle rims and top speed increased to 87mph.

Wish I still had that truck.

 

[LameUsername]

What issues are you talking about on the Gen 2's ..
Pesky issues ..
I'm going to say GEN2'S DON'T HAVE ISSUES .
i WORKED FOR A DODGE Dealership for 11 years back in the service dept.
Now the dodge 2005's up until about 2010 sure had bad nasty issues.. Fuel systems killing motors . Is that the issues your talking about .
........ But the loud diesels motor didn't have the fuel issues. It was after the Quiet motors came out .

He is talking about the VP44 fuel pressure issue with the stock lift pump, and I really don't want to slam you but the way you describe loud and quiet Diesel "motors" I highly doubt you did anything other than stocked parts at a dealership.

 

[LameUsername]

Hey all haven't posted in a while but wanted to find out what to do.

I have a 99 Ram 2500 cummins 5spd, running stock 3.55 gears with 285 75 16 tires. The stock tires are 245 75 16's. When driving on hwy at 70-75 I am still getting 14-16 mpg but my rpms are like 2400. Is this ok to run? I plan on not going any higher than 70 in this truck. We are also looking for a trailer to tow with for trips.

Would it be a good idea to get near gearing? I have heard if I went to 4.10's it would make my rpm's jump. What is a good idea? I am stuck...

Thank you all in advanced for information.

Those RPM's are normal at that speed with that generation truck, My 95,96 and 99 with 47RH and 4.10' would run those RPM's with stock tires. I put 35's on all the trucks to bring it down a little.

 

[PaPitt]

Well Lame.. you name fits you so well.
Service department all those years. Had 8 techs working.
.......................
...... When I left I had over 200 phone calls to my cell.. THANKING ME FOR MY SERVICE. & They said they could alway appericiate how I explained their situation. Even when It wasn't what they wanted .. They believed me in what i EXPLAINED TO MY CUSTOMERS .
......
Lame please don't turn this web sight into an bickering name calling sight like Pirate4x4 .& some others. This sight does an excellent job of helping . New members Build their Rides. I've been a member here for many years . back before this sight was bought out & started over. I joined somewhere about 2007. & My 1972 with a 4BT CUMMINGS in it .. WAS BUILT WITH a lot of help & Parts purchased from members from this sight. & I believe it's been running & driving since 2010 . It's very handy on my Farm. I used it about like a tractor. Dragging trailers, Hay rakes, Grain Drills, Hunting & SIMPLY Cruising the Pastures & Country roads..
Now go add some quality info to your 3 post..
Thank You.