very poor to aweful fuel mileage when towing

[RLJ10X]

The times that you catch a tailwind instead of a headwind, that will have a bigger effect on mpg than 3.21/3.55/4.10 rear end gears.

In the 545RFE, 4.10s do pretty good mpg wise, until about 60 mph. Above 60, things deteriorate rather rapidly, at least in my truck.

With the 545RFE, the 4.10s really earn their keep when Towing.

No doubt, an 8 speed with 3.92s would be cool. But if you have a good, low mileage 2011, which isn't horribly expensive to re-gear; Re-gearing is much more cost effective than trading up to a newer truck.

That money that the one or two mpg that the 8 speed saved you, went ****! when you had to service it. No free lunch either way you go.

 

[farout75]

Well considering the year and the transmission with five speeds (am I right?) that to me seems pretty average. My 17 RAM with the 5,7 and 8 speed gets 10to 12 when I tow a enclosed 18' trailer.
Most likely your truck is paid for, and if you had a brand new RAM that got, say 12 mpg towing then add the payment it adds up. Your doing great is gas and insurance is all you have to pay for. Besides with 44,000 miles its barely broke in. My 17 RAM has 88,000 miles on it. You are blessed!

 

[teammontana]

I have a 2015 2500 6.7 with auto and 3.21 gears. When towing a 26’ toy hauler loaded at 70, I only get about 9mpg. Unloaded it runs 18-19. Only have 29k miles. Has all the power I need to pull mountains, etc., but seems like wind is the biggest factor. Disappointing economy compared to my old 2004 with 6speed that got @11 over the same trips.

 

[tjfdesmo]

I have a 2015 2500 6.7 with auto and 3.21 gears. When towing a 26’ toy hauler loaded at 70, I only get about 9mpg. Unloaded it runs 18-19. Only have 29k miles. Has all the power I need to pull mountains, etc., but seems like wind is the biggest factor. Disappointing economy compared to my old 2004 with 6speed that got @11 over the same trips.

I think you mean 3.42's?

 

[srwa]

Am pulling a 14k 5th. wheel with an 01 Dodge 2500 Cummins 6 speed @ 70 mph. Average 11 mpg. No load; 21 mpg.

 

[Robert Fly]

I headed out for Alaska in May of 2016 with my new Ram 1500 5.7 8 speed 3.92 gears and a 5th wheel trailer. The Lyometer came out to 10.5 average for the entire round trip. I had budgeted $5K for fuel, oil and what nots for the truck and came in right on the money.

 

[RaptorHD]

An Eaton-Fuller in a 1/2 ton? A Roadranger? The transmission alone probably exceeds the payload rating of the truck.

No, not a road ranger (Wtf?) Do you beleive that Eaton fuller only makes the road ranger?---NO... I recommend you go to this forum, plenty of trucks doin the Eaton swaps :https://www.cumminsforum.com/forums/