I know I've seen it before but I don't remember the out come so here we go. I was going to order a 2005 Ram3500DRW 4X4 with the 3.73's. I only tow approx. 1,500 miles a year. The 5th wheel weighs approx. 11,500#. The rest of the time, I tow a light motorcycle trailer or nothing at all. I only put around 12,000 miles a year on my trucks and only keep the for around 4 years. Anyway, the local dealer ship has a 2005, automatic 3500 on the lot with just about the exact equipment that I would order it with but it has 4.10's with antispin. How much poorer will my fuel mileage be with the 4.10's vs.3.73's?

 

4.10 drives up your rpms

 

Hedgehog, you're in pretty much the same predicament I was in when I went to order a truck. I wanted 3.73's but the truck that was there had 4.10's. I have no regrets having 4.10's; and can get almost 21 mpg on the superslab.

 

3.73s all the way if it were up to me. My last cummins had 4.10s and anytime i went out on the interstate i wish i had a different ratio. Unless i was running huge tires or pulling alot more heavy miles i would wait and look for a different rig. At 70mph+ the differance can be 2-3 miles to the gallon. If you drive 60 mph or less, i dont think it matters much. Good luck!

 

I have 3.73 with the 6spd and I'm always trying to shift to 7th above 65mph. I wish I had 3.55's. When it's time for new tires, I will go to 285 or 295 just for the gearing. I have towed a 7k travel trailer 4000 miles with ease. It even starts in 2nd gear when I forget to use 1st.

 

If it were me I would get the 3.73:1 ratio. I haul a heavy load about 30-40% of my milage. The rest of the time i'm basicaly empty. 3:55:1 would be nice then! If I hauled a load 50-60% of the time I would go with the 4.10:1 with a 6 speed for sure. The 3.73:1 are nice to travel with empty.

 

3.73 would be ideal for your current situation but I think the fear of 4.10 is out of proportion to the facts. You will lose about 1 mpg and yes it will rev higher but my truck still tops out at 105 mph. Marine diesels run at 3000 for days at a time without any problems. At 70 mph you are going to turn around 2500 rpm. No big deal for this engine. And somewhere down the road if you need heavier towing capability, then you will have it. If you want the truck badly, don't let the 4.10 axle scare you off.

FWIW. Casey

 

The 1 mile per gallon rule with 4.10s doesnt hold when speeds above 70 mph are calculated in. At least thats been my exp.

 

I live in the land of no speed limit autobahns and I need 3.55s. With 4.10s, the first 2 gears are useless. I am in 3rd before I cross the intersection. I never had a vehicle that accelerates harder in 4th than in 1st. The fuel economy is only a little bit worse with the 4.10s though. I don't tow, but I carry heavy machinery.

 

I have the 4:10 and am going to install the "GearVendors" overdrive unit. It bolts behind the tranny and when engaged will reduce the axle ratio from a 4:10 all the way down to 2.98s!!!

 

Man that sounds awesome. Out on the slab i wish i had that setup or a 7th gear.