4:10 or 3:55 with 6 speed????

[E7mack96]

The new truck (2002 eth/dee) i am looking at has the 4:10. I currently have the 3:55 (2001. 5 eth/dee). I have been able to get 20mpg out of the 3:55. will I lose mileage or gain it with 4:10. I am afraid of losing mpg. Most weight i ever carry is 6,000 in the bed. Mostly empty miles though.

 

[jwinnie]

Go with the 3. 55's no question. unless your going to run oversize tires. keep the rpm's down since your not moving much weight.

 

[Ted Constantine]

My ETH has 4. 10s on it. I have gotten 21+ on road trips easily. The only thing is above 75 I am revving up a little. I think while towing if I had 3. 55s I would be in and out of 5-6 gear now a rarely shift. It runs right in the sweet spot.



Ted

 

[abledog]

Depends on the application, 2X4 or 4X4, stock tires or oversise, heavy or light load.

Do you plan on BOMING? This may have some bearing on the most desirable axel ratio.

I have a 2001 3500 4X4 ETH/DEE with 4. 10's. The truck is mildly bombed with 275's,VA and propane. I us the truck mainly for towing and am very pleased with the overall performance, The only issue I have is with the way the trans shifts!



Terry

 

[LSMITH]

If you are going over 33" tires get the 4. 1, otherwise get 3. 5 gears IMO. The 6 speed is so good that the 4. 1 gears are really not necessary even over GCVW IMO. I would not even consider a DEE with 4. 1 gears unless I had planned on 35" tires.

 

[JHansen]

Love my 4. 10's-I liked them even with the stock 265's once you got used to the RPM (last diesel before this one was a KW with 475 Cat and 15 over that turned around 1400 at 60 mph!). I don't think the 315's I run now would be a whole bunch of fun with 3. 55's-not so much a power issue as being too high-speeded for manoevering around without shifting to 4 Low. Everybody's got a little different take on this subject so I thought I'd throw mine in!



Jason

 

[UKRugbyman77]

Well I already got 355's and I'm thinking about going up to the big BFG's (37x12. 5)'s. Is that gonna be something that I'm absolutely not going to be able to live with? I mean I don't even use 1st to start off, I would think that even if it brought the gearing "up" you might be able to deal with it by "shifting" the gearing- starting in 1st etc. Does that make any sense? Somebody give me some insight. Putting these BFG's is already going to be a $5k job (wheels/lift/tires), am I gonna HAVE to lower the gearing when I do this???:{

 

[THancock]

I'm with LSmith on this one I love the 3. 5s. Hardly ever have to shift down when loaded, but when I need to, I can still pull the load at 70mph in 5th. I'm empty 90% of the time too. And I'd rather keep the revs down as low as possible at all times, stick with the 3. 5s.

 

[RustyJC]

If you're looking at a 3500, the ETH/DEE with 4. 10's has a GCVWR of 21,500 lbs. The same combo with 3. 55's has a GCVWR of 20,000 lbs. If you tow heavy like us and need the additional GCVWR, go with the 4. 10's. If you don't, stick with the 3. 55's.



Rusty

 

[jbone]

If Ted is getting above 20 mpg with 4. 10's, he is the only one I have read here that does!?! I'm getting about 15/16 mostly around town--just installed EZ--see if that help or my lead foot can be kept in check!!! R, J. B.

 

[10-G]

I just took delivery of mine on saturday, 6 speed with 3. 5s. It is a goat, with 4. 10s it could be used as a field tractor. You will have plenty of power to turn big tires. I wont be using 1st much around town. The biggest thing I pull is a #8,000 TT. In fifth it really sings. Fifth is great for merging into freeway traffic.

 

[NVR FNSH]

I drive a '00 4wd 2500 6spd w/4. 10s & 315/75s. Towing my 36ft Patio Hauler 5th wheel on relatively flat ground (I-5 from Williams to Vacaville) I'm running 66mph (per GPS) at 2000rpm in 6th gear. I get 10 mpg towing at a GCW of ~21,000lb. I'd like to run @ 60-62 mph for the MPG but it would be at too low of a RPM. 5th gear would be too slow.



I'd go with 3. 55s if 6K is the max your going to tow/haul. 6K in the bed will put you at ~13K GVW.



My first reaction to Ted's 21mpg in 4. 10 geared 4wd was BS as well. I'd like to see the data and the break down of how the engine bombing affected his MPG. I'm happy when I get 17mpg...



Brian

 

[IdaH.O.Train]

3.55's

E7, stay with the 3. 55's. I'm assuming you carry a slide-in, hence the 6K in the bed. So I don't think it's going to make that big of a difference if you go down to the 4. 10's. Besides, you're already used to how the truck drives with the 3. 55's.

 

[Chipstien]

Originally posted by UKRugbyman77

Well I already got 355's and I'm thinking about going up to the big BFG's (37x12. 5)'s. Is that gonna be something that I'm absolutely not going to be able to live with? I mean I don't even use 1st to start off, I would think that even if it brought the gearing "up" you might be able to deal with it by "shifting" the gearing- starting in 1st etc. Does that make any sense? Somebody give me some insight. Putting these BFG's is already going to be a $5k job (wheels/lift/tires), am I gonna HAVE to lower the gearing when I do this???:{

I think you would almost need to go to 4. 10's. I have 35's and did a few calculation once and found out that running 35's and 4. 10's is the same as running 265 with around a 3. 68 rear end ( if they made such a size ). 37's and 4. 10 gears will put you right where you are now with stock tires.

 

[Ted Constantine]

Jbone, Brian and any one else.



I am refering specifically to one trip a month and a half ago. Bozeman, MT to Moab Utah and Back. In a weekend.



The mods at the time:

JRE 4"

JRE cold air heat shield w/ AFE cone

275s

Comp 1/2 or 2/2

295/75r16 BFGs

DOR bumper w/ warn 12k

cab level topper

amsoil F to R 75w90 (axles), 5w30 (engine & transmission)



The load was me at 185 lbs a fifty pound dog and 300lbs of other stuff.



I ran 68-73 mph on highway with the exception of a traffic jam in Salt lake. No notable wind on the way down and got 21. 5 mpg calculated by hand. I was ecstatic! I was being conservative and smart with the go pedal. On the way back there was a good head wind for the beginning of the trip and weather was not as good I got 20. 45 mpg. I filled up in bozeman leaving, in moab on arrival, moab after arches and then in bozeman again.



I have no viable data on effects of each bomb on the mileage. They started while the engine was still breaking in and have happened in groups. I have gotten as bad as 12 mpg and I rarely have the restraint to drive normally. At 26 years old I am still a yahoo.



I ran out of fuel yesterday although the gauge read just under a 1/8. This tank was mostly my father taking the truck to haul furnature for my sister. All highway driving. He is more restrained than me. 845. 127 corrected miles and 36. 127 gallons for a total of 23. 39 mpg. This is with my DD2s.



Here is the ran out of fuel thread



Ted

 

[Karl2500]

I got 20. 1 MPG on a run from Long Island to Charlotte in mid Sept. calc. by hand. Stock everything and fairly slow speeds, 55-65. almost empty just me an the wife.

 

[K-Man]

3.55's

I have a Y2K 3500 with a 6 spd and the 3. 55 rear end. I tow a 13K (fully loaded) horse trailer and really like the setup. I only drop down into 5th gear when making long pulls on some pretty good mountains (Bradshaw Mtns north of Phoenix, Tehachape and the Grapevine in California, etc). I like the fact that the motor spins a little slower and just seems to run a little easier. With this motor torque and pulling power are no problem at all...

 

[juicedcummins]

355's are the only way to go because of the lower overdrive ratio in the 6 speed.

Some people seem to think that these things should scream all day. That's better left to the V8's!

 

[Joel Richards]

Originally posted by jbone

If Ted is getting above 20 mpg with 4. 10's, he is the only one I have read here that does!?! I'm getting about 15/16 mostly around town--just installed EZ--see if that help or my lead foot can be kept in check!!! R, J. B.

I get 21 mpg with my 4. 10's. Before the mods, I got 16. I personally would not be without 4. 10's. Great for towing heavy, great for wheelin'... Had them on my '98, most likely will have them on the next one too. If you can stand the 2500 rpm at 75 mph , go for it...



Joel

 

[PRout]

Sounds like different strokes for different folks here. Almost everyone likes what they have.



Im with LSmith also, and love my 3. 55's.



W. the 6 speed theres no reason to go with 4. 10s, as theres a gear for everything. In fact, 5th gear is stronger than 6th, so if you downshift up a grade, your right where you want to be. Or you can still use that INHERENT torque of our CUMMINS (just rubbing it in to our FlowerStroke & Dcrack readers), and pull 70+ over grades in high gear.



Why would I want to limit myself going to 4. 10's. 3. 55 have a very comfortable cruise rpm w/ 33inch tires.



I have to question the guys that get claim 23 mpg's w/ 4. 10's though. Maybe with big tires, or a tailwind, but Ive seen 20 only once or twice, and it goes down at higher r's. Avg is about 18. 5.