gear ratio question

[pitbull]

Ok im tryin to learn a thing about gear ratio. My truck build sheet says it has a " DMDP 3.55 rear axle ratio and a DRBP Corporate 9.25 LD rear axle" what exctly does this translate to in language so I can understand. Is this geared twards power, avrage daily driving, or what ? The truck is a 2000 ram 1500 5.9 with a 4 speed trans

 

[03MopaRamman]

I'll let the 2nd Gen Gurus answer but based on experience and my buddy has a 2nd gen with 3.92's all I can say is the 355 is a dogs awrse when it comes to towing anything over 4K lbs but then again a 4 speed might be different and LD is likely an open diff. I'm sure one of the Lads will answer this in depth shortly.

 

[SmokedRam]

When I had my Gen2 I had the 318 with the 3.55...wasn't bad once you got her up and going up on the highway, but driving in town sucked.


My Gen3 has the 3.92 and it's get up and go is so much better.

 

[Stangshcky12]

3:55 is your rear axle ratio
9.25 is the type of rear axle in your truck
lower gear ratios like yours are more suited for highway driving as it allows for the engine to turn at lower rpms at highway speeds

 

[Bigboytoys]

3.55 is the differential gearing...basically your drive shaft will spin 3.55 times for every 1 time your tires turn. 9.25 is the ring gear diameter (someone correct me if I am wrong)

 

[Hotroder383]

^^^^ What he said. That is a "high" gear set, I have the same in my truck. It is good for MPG on HWY driving but not so good for towing or TQ. I want to go down to at least a 3:93 maybe 4:10. But my truck is mainly for play and towing, a good trade off is the 3:73, got a bit of "umph" at low end but not so low as to affect MPG much more than what you got.

 

[pitbull]

Thanks guys sounds to me like I might think of making a change in the distant future but not right away. I dont do alot of towing this is a daily transportation/toy but I would like to have a better take off. I dont see myself needing to tow 4K ne time soon lol. But I have a BASIC understanding if gear ratio now

 

[Bigboytoys]

I am going to 3.92s soon. Little more on take off, but can still maintain decent milage.

 

[SmokedRam]

I am going to 3.92s soon. Little more on take off, but can still maintain decent milage.

Yeah you'll like them. I average about 17.5-18 with my driving. If you keep it as 60MPH and 1650RPM's on the highway, you can easily see 21MPG. At least I do in my RCSB.

 

[Bigboytoys]

Ya...with my 3.55s the sweet spot is about 62 mph...I can average about 19 mpg, but the thing that kills me is hills, and the fact that it is hard to keep the cruise control set on the autobahn as everyone is doing about 115 mph...

 

[Stangshcky12]

Give towin a shot and see what you think about the truck
4k isn't much, you might be happy with the way 3:55 pull it