Get 4.10's or 3.54's?.................

[V6power87]

Looking at new trucks, 2001 4x4, quad cab, auto, etc.



What are the pro's and con's between the two ratios?



What rpm in OD do the two run at down the highway?



Thanks.

 

[KatDiesel]

4. 10 here, i got the 4. 10 ratio in preparation of lifting the truck and putting on 35 to 36" tires, which would bring it back down to roughly 3. 60 ratio if I go 36" tires.



RPM depends on what speed you travel at? Too many driving habits to list them



I currently have 285/75R/16 on my truck (orginally had 265/75R/16) so my speedo is off. Only bummer is when I get up around 100mph on the speedo I don't have much left due to the govenor, I am prolly going 105mph to 110mph tho, haven't really took the time to do the math.

 

[Barry]

With that set up, 4:10s for sure... ... ... 60 mph should put you somewhere in the 1950 rpm range... ... ... .

 

[MikeR]

The . 69 overdrive ratio in the automatic is geared to low with 3. 54's and the new taller tires to work at optimum efficiency... and I'm not just talking fuel mileage,I'm talking fluid pressures and heat buildup in the trans. A highly regarded diesel trans builder in the NW says 4:10's with the auto is the choice.

 

[Skyjacked Ram]

4. 10 with 33in tires, feel just right... . 3. 54 with 33in tires, truck is alittle slow and in my opinion alot of slippage from transmission under hard excelleration... at 75 mph with 4. 10 and 33in tires I am right at 2000 rpm, right in the middle of the "sweet spot".

 

[SnoKing]

If you are going to tow, get the 4:10's. I turn 2K at 63MPH. Towing with 3. 56's you would be out of OD all the time. Lots of power for the hills in 3rd lockup. 2700 in 3rd lockup will give you 60MPH or so on the hills. Snow King

 

[.44 mag]

I did a lot of reading on the 4. 10 vs. 3. 55 debate before ordering my truck. It seems to be if you want a 4x4 with an auto trans. then the 4. 10 gears are the way to go. If you are a speed freak on the highway and want to run 90mph all day, get the 3. 55's.

My truck sits at between 2000-2200 going down the road at approx. 70mph. It's right in the power band and pulls strong up to 2600rpm or so. It's just my opinion, but I think the 3. 55's are too high of a gear for the automatic 4x4 given the 33+" tire sizes folks are running.



Hank

 

[LSMITH]

If you are going to get larger than the factory tire size DO NOT GET the 3. 5 gears and an auto trans. The manual trans would probably be OK but not the auto. 4. 10 gears is the only way to go with the auto trans IMO, I have the 3. 5 gears and I am sorry. It is too high geared with the 33in tires I have, you are never in the sweet spot for power unless you are rinning 80 in OD or 55 in drive.

 

[Big White Beast]

I swapped from a 4:10 to 3:54.........

When I first got the truck it came with the 4:10's. Seemed like I was red line all the time trying to keep up with freeway traffic. MPG was terrible too. Toting 10K+ lbs daily it was good around town though. I found someone who wanted to swap gears which made the price right. At first thought I made a mistake.



Freeway was better but out of the sweet spot unless I was going in the slow lane (Hate That) or really pushing it at 75-80. MPG's didn't change one bit. Being that San Diego is hilly, lots of long grades, it seemed I could never get it the truck where I wanted it. I really wish they made a gear in between.



The good news is after I installed the EZ the truck seems to run great in all driving conditions. Seems the 3:54's just needed that little bit more power.



I am now happy with my swap. The RPM's are lower, I don't feel like I have to work to keep up with traffic. Again I tow very little just the daily weight, if I were towing much heavier loads I probably would have stayed with the 4:10's.



Garrett