I am looking at a 2011 Ram 1500 CC 4x4. It has the 5.7 and 3.92 rear gears. It also has the anti slip differential and trailer brake controller. I am trying to get a little information on highway and fuel performance. How does that low of a gearing ride on the highway and is the MPG's really bad because of it?

 

I have the same setup and find that engine rpm's are actually quite leisurely on the highway; around 1600 at the legal limit of 60-65mph.
Others have stated that city mileage is actually better with this gearset than the 3.55's.

If anything, do a search on this forum for the many owners wanting to change to the 3.92's with the LSD. I doubt that I've ever seen anyone wanting to go the other way.

And trust me, it is WAY cheaper to do this oem compared to fiddling around buying new gear sets and finding someone to install them properly.

BTW, my mileage with the 3.92's is about 24 at 60mph and 22 at 70mph.

 

You will not take a noticeable mileage hit with the 3.92's. In fact around town you may fair even better than other gears because the Hemi is in its sweet spot more often. I think the advantages in towing and acceleration far outweigh any small mileage hit. Plenty of posts where folks regretted not getting the 3.92's, but I have yet to ever see anyone wanting to switch to the 3.55's or 3.23's

 

3.92, without a doubt. Definitely performs better, just drive one with 3.55 and you'll see, plus, I regeared our F150 and it was about 2200 bucks total. I drive 80 miles round trip to work, mostly highway, and get 17.6 - 18.4 on the EVIC in warm weather. This is even traveling at 70 mph and with MDS disabled. Almost bought a Tundra with 4.30 gears but the Ram Sport with the integrated duals was just no comparison imo. I just hate this crap MDS system Dodge is into and think it is more noticeable with the 3.92 gears but there are a few ways to disable it temporarily or permanently.

 

very interesting! I have driven a few 3.55's but have not driven the 3.92 yet. I am very surprised that someone has said that the 3.92 will do better around city driving. I am in Mobile, Al. and the city driving is horrible. I get 13 miles a gallon in my V6 Dakota. Is it a much more noticeable difference with towing. I realize it makes the truck go from an 8550 capacity to 9950.

 

Guys, Have you ever heard of someone having equipped his 2011 4x4 RAM Quad Cab SLT Hemi 5.7L 5sp Auto, with 3:92.1 front axle ratio, and 4:10.1 for the rear axle? Well my front axle won't take more than 3:92.1, while @ the back I can reach 4:10.1 max...@ the dealership they told me that it is possible, but I am not quite convinced of that
Any advises?

 

It would only work with out severe damage in mud.

 

Front and rear gears must be same.

 

If you NEVER engage 4wd you will be fine.

If your good in math you can change the size of your tires to match the numbers of the rear gears and that size of tires. Then you could use 4wd with different ratios.

 

How come I was advised by our local RAM dealership that front and rear axle ratios don't have to be the same???
Me not using 4 Wheel drive is like asking the pope not to pray
I am really confused now as my RAM, and according to this same dealer, originally came with 2 different axle ratios