2nd Gen Non-Engine/Transmission Axle Ratio

[ANG012]

On 2002 3500 what is the fuel milage and noise different between the 3:55 and the 4:10 on the high way. I live on the east coast and do not tow heavy loads. Will be running high way speeds 65-75 mph. By the way it is a automatic trans.

 

[Udaloy]

3. 55's will allow you to cruise at those speeds without the motor going over 2000 rpm. But if you are running oversize tires (315's and bigger) I'd suggest the 4. 10's. My '02 auto 3. 55's lost mileage when I went to the bigger tires. I don't know of a noise issue with either.

 

[rkressg]

I get around 15mpg with 4:10 + 6-speed. The guys with 3:55 + 6-speed usually get around 18mpg. Not sure with autos, never really checked.

-Rich

 

[BKenny]

Yep, if your not towing big loads and climbing mountains id go 3. 55. With the 3500 you must be talking about a duely . Its harder to run big tires on them i have 4. 10s and im going to upgrade to 315s tires to drop some rpms

 

[dodge cummins]

i got a 4. 10 rear on my 96 4x4 and i am getting 20mph on winter blend fuel

 

[bmoeller]

You need to drive faster, FANZ. 20 ain't much. :-laf Couldn't resist.

 

[trqmnstr]

I'm getting 25mpg out of my 6spd 3. 55 cruising at 75mph on the highway. I've never heard of that much!!!

 

[Udaloy]

Bull****! No one is getting 25 MPG. Not over the course of a whole tank, and especially not "cruising" at 75 MPH. This website and group membership are about knowing and learning all we can about our vehicles. That is not possible unless we are intellectually honest with each other. It would not be a fair expectation by ANGO12 to get an average 25 MPG. He should expect 14 to 17. There are so many variables in the mileage a truck gets, let alone the method in which you calculate it, that it's not possible to give a more precise answer than that.

 

[archer2500]

On 2002 3500 what is the fuel milage and noise different between the 3:55 and the 4:10 on the high way. I live on the east coast and do not tow heavy loads. Will be running high way speeds 65-75 mph. By the way it is a automatic trans.

I have a '00 2500 quad cab 4x4 6-spd (not HO) and I get a solid 18 highway and around 15 city.

 

[EricBu12]

guys, heres some math for you to figure on axle ratios I saw on Extreme 4x4 show





Tire size diff ... ... ..... Axle ratio... ... ..... New ratio/ or needed Gears



31" stock tire divided by new 37" tire X axle ratio 3. 55 = 2. 97 <---That would be the new ratio.



the other way to figure it to try to get the ratio back to stock with gears is



37" new tire Div. by 31" stock X 3. 55= 4. 23 <---thats the ratio you would need to get the rpms back to stock.



I am getting 245/70-19. 5 and I have stock 265/75-16 and I have 3. 55's



so the stocks are 31. 8" Divided by the 245's which are 33. 8" X 3. 55 = a new ratio of 3. 33



So thats how you can figure out exactly what you need or have when getting bigger or smaller tires

 

[Tom L]

Axle Ratio/Mileage/Noise?

I have a 2002 2500 2wd x cab, AT w/od. Rear gears are 4. 10, tires are 265/75R Michelins. Mileage at 70 mpg empty ave high 16's over tank life. Driving 65 of course mileage goes up, Pulling trailer naturally mileage goes down dramaticlly, 9-11 ave. 3. 53 for folks who enjoy trucks and use them as a everyday means of transportation, if you are going to work the thing, 4. 10, unless you have the Big Motor then 3. 73 in my opinion would suffice. Not sure what you are asking about noise tho? TL

 

[trqmnstr]

Udaloy, that's no bull **** !!! I usually average about 19. 5mpg with 75% city and 25% highway miles. Whenever I take an empty trip I cruise between 70-75mph and I'm turning about 2000-2100rpm. My last trip was from NC to FL and my last tank of the trip I had about 420 hwy miles and the rest were city that I put on when I got home. I did the math and it was 24. 7mpg!!! The only time I dip past 19mpg is if I'm towing or I have a hot foot. Call me a liar if you want but that's the truth.

 

[SnoKing]

I'm getting 25mpg out of my 6spd 3. 55 cruising at 75mph on the highway. I've never heard of that much!!!

Maybe you are using imperial gallons. Or maybe your speedo is screwy. But then again you have a 2x4 and manual. SNOKING

 

[jraker]

I have an 01 with 4. 10's and an auto. If it is bone stock you should get ~14. 5-15 mpg cruising around. Mine seemed to get this if I went 60 or 90. I then upgraded my tire size to 315's (very nice look). I also put the Banks kit on an loaded up and drove from Seattle to Alabama. With my bed completely full of furniture and the milage was hand calculated I averaged 19. 63 mpg over the 2592. 4 mile journey. I must have had a good tail wind or gone mostly downhill. Since that time I am regularly in 17. 6 to 18. 2 range. I have an occasionally 19+ tank but then again I have an occasional 13. 4 tank.



As far as the noise goes that also depends. How big the exhaust is, the tread pattern on the tires, what size your turbo is, do you have a muffler, is there a silencer ring still in the turbo or your air box. Fact is these are loud trucks and there are many posts on here of people doing things to the interior to quiet them down. I have yet to do anything to my interior, someday maybe but I have no time now. It doesn't bother me nor my wife. The sound of the truck puts my wife out along with the kids. Then it is just me the truck and my lab.