2003 Dually: 4.10 or 3.73?

[KCJackson]

With 265/70R17E tires and 75 mph:



48RE/3. 73 in OD - 2105 rpm

48RE/4. 10 in OD - 2315 rpm

5600/3. 73 in OD - 2225 rpm

5600/4. 10 in OD - 2450 rpm



Steve's guess of 2150 is pretty darned close.

 

[sdbelt]

KC is correct. I paid very close attention to my rpms on my drive home from work yesterday, and 75 mph was indeed just a hair over 2100, not 2150 as I had recalled.



My speedo is dang near perfect, as I've checked it at numerous places. This truck has the most accurate odo and speedo I've every driven.

 

[dlessard]

I tried a '03 3500 Dually 48RE Auto 3. 73 last week-end.

At 75 MPH, RPM is only about 50 RPM more than my current truck (Y2K 2500 Cummins 47RE Auto 3. 54).



'03 Dually = approx. 2100 RPM

Current truck = approx. 2050 RPM



Denis

 

[Fireman]

Are you guys towing at 75 mph?



You won't get fuel economy for.....



Fireman

 

[Barry]

..... only when someone is trying to be smart and not let me back in the right lane... ... ... ... ... ... ... ... ...

 

[Dean Upson]

After having had a 94 auto 3. 54 I went to a stick on the 98. 5 with 4. 10s. I now have an '03 with a six speed and 4. 10s and, for me, I now have the perfect combo for towing heavy.



Dean

 

[DLeno]

Originally posted by Barry

There should only be 60 to 70 rpm differance between a manual/3:73 and an auto/4:10.

yea, and for this reason I wouldn't consider these two final drive ratios to be "almost identical". the difference is 4%, and thats worth 80 rpm (identical tires) if you drive 70.



Also, remember that as tires wear they will give back as much as 50 rpm.

 

[DLeno]

Originally posted by Peter Campbell

I ordered the 4. 10/6sp and the SRW. Not yet in "D" status. The 3. 73's have 2,000lbs less GCWR than the 4. 10's. IMHO If you are not planning to bump into 21,000Lbs GCW get the 3. 73's. I wanted every bit of "nameplate" capacity that I can get with a SRW truck. Did not want to pay for two cars going through every toll in new york. For the 6 speed GCWR that would be a reason to go with 4. 10's. My present truck is 4. 10"s and auto. With the auto if in doubt go with the 4. 10's- you can cheat later with tire size- or use it as an excuse for bigger tires

this is a great answer. and really, if you're out to get a dually you have monster payload capability and yet with 3. 73 gears you will be GCWR limited -- that extra 2,000 lbs is a lot when you're looking at some of the larger 5vers. nameplate towing capacity is not all bogus -- it may come in very handy if you're involved in an accident and there are insurance or liability questions.

 

[sdbelt]

Yes, I tow my 12k lb 5er at 75 mph. That's the legal speed limit here in AZ. In CA, I usually do whatever the trucks are doing, which is between 70 and 75 along I-10/I-5.



So far I have over 8000 towing miles with my rig, and I'm getting right around 11 mpg when running 75 mph on the highway.

 

[Snow man]

I towed my new Sunnybrook 33 ft travel trailer at 70-75 mph for 450 miles,up thru upstate Ny where there are some long hills,nothing real steep,but lots of long rolling hills. I averaged 11 mpg with my 4. 10 gears,and my tack stayed at 2100-2300 the entire time,that is perfect RPM for pulling IMO,the motor never lugged and it never felt like it was wound too high.

 

[Dean Upson]

Originally posted by Snow man

I averaged 11 mpg with my 4. 10 gears,and my tack stayed at 2100-2300 the entire time,that is perfect RPM for pulling IMO,the motor never lugged and it never felt like it was wound too high.

I really love this truck at 1900-2300 rpm and I am quite comfortable with the 4. 10 gears while towing. I usually tow around 62 mph except in hilly country when I like to give it a little more to carry the hill. The truck never lugs with this gearing and my trailer goes about 15k loaded .



Dean

 

[LStewart]

I have a 2002, quad cab, 4*4 auto; single wheel with 4:10's. The dealership I bought it from ordered about 15 with auto's and 4:10's; I would never have 3. 54's. The pickup and response is excellent and towing is much better. My dad has a 2wd reg. cab auto with the same gears and he is very pleased.



Folks we know with the same setups with 3. 54's are not happy with the power at all; both unloaded and towing. These trucks are too heavy to have auto's with highway gears in my opinion. I had a 5-speed with 3. 54's; that's not too bad.