Gear ratio for RV ?

[Cranky]

When I bought my diesel back around 2000, I was using it a good bit but haven't so much as of late since I sold my race car but also, the rear gears were starting to whine a bit so I changed the rear end oil and added some STP and that helped but I knew they were not long for this world and well, they are not whining anymore.....they're yelling lol. Anyways, I got my 5th wheel hitch installed in it the other day (man, those are a pita!) and I'm ready to make a test tow. I want to see if I should change my ratio before tearing into it. It has a 3.54 now but it also has 31" tall tires. The trailer isn't that heavy (5800 title weight) but has a fairly high profile. I've towed some heavy trailers with it but none had such a high profile and I'm wondering if the wind resistance will dictate a 3.73 at least? Guess I'll find out soon enough....if the 3.54's don't decide to take a complete crap first.

 

[Budnicks]

My rig is a 4x4 Turbo Diesel dually with 4.10:1 w/6sd OD w/granny low, with just under 31" diameter all weather tires it likes the lower gears, especially towing or driving in the mountains, if I lived in the flat lands, I would have went with probably 3.73:1 gears or something close to that ratio, they are a great compromise, but it never sees over 3500rpm while towing & about 2500rpm @ 70mph in 6th gear OD, the trailer is I think around 8200lbs loaded {about the same as the truck loaded GVWR}, with, cloths, bedding, fresh water 100gals & water hose, groceries & libations, cookware/dishes, TV's & Radios, waste/dump hoses Grey water tank, 30amp & 50amp electrical hook ups & extensions for everything, cable & phone stuff, various thicknesses of extra wood blocks for easy leveling set-ups, trailer axles wheel chock/locks, awning, tarps/carpet for outside, fishing stuff, guns stuff, golf equipment & other toys, chemicals, propane, generator, batteries & fuel, lounge chairs, folding table, out-door & BBQ stuff... The weight really starts to add up fast...

 

[Cranky]

Dang man! Way too much 'stuff' to take. All I want to do is go some place and kick back and relax...ice chest and some beer is all I need lol

 

[Budnicks]

Yep

Dang man! Way too much 'stuff' to take. All I want to do is go some place and kick back and relax...ice chest and some beer is all I need lol

:iamwithstupid: I thought the same thing, I know it starts pilling up quick, especially if your bringing a woman along...

 

[moparsteve636]

Budnick,What kind of fuel mpg you getting? I pull a 44' with LQ and just about the same amount of stuff!The trl.though weighs in at a hefty 11,000#s.Just curious,What they chg.at racetracks for food and such not to mention motels!it cheaper in the long run carrying all that stuff.BTW mine is an 06 cummins,auto with 3:73 gears.I avg.15-17 mpg.

 

[Budnicks]

Budnick,What kind of fuel mpg you getting? I pull a 44' with LQ and just about the same amount of stuff!The trl.though weighs in at a hefty 11,000#s.Just curious,What they chg.at racetracks for food and such not to mention motels!it cheaper in the long run carrying all that stuff.BTW mine is an 06 cummins,auto with 3:73 gears.I avg.15-17 mpg.

You get way better than I do, Pops drives it more than me & pretty much babies it, it's a 2002 F-350 4x4, 7.3 Powerstroke, 6spd OD, 4.11:1 gear, 31" tire, 4" mandrel exhaust, 40 gal. tank, re-timed pump, Power Chip & K&N filter, average 13-14mpg hwy to "maybe" 15-16mpg max on flatland freeway/hwy & a little less like 11-12mpg in the mountains with fully loaded truck & trailer... Both are around 8200lbs each fully loaded... The truck really needs a wing so it isn't fighting physics/aerodynamics, just haven't done it, the truck has 95K mile on it now, Pops uses it like its his personal commute car... He's an ex-School Bus Driver, that may explane some stuff... I liked my old 95 Ram 4x4 5.9ltr Cummins much better...

 

[Cranky]

Last time I pulled long distance, it got 17 running 80 most of the way but the trailer and car was only about 4500 lbs total. The truck has hit 25 running empty and usually gets 19 in town but since they changed the makeup of the fuel (less sulfer and oil), it hasn't hit 25 again. If they keep refining it to be cleaner, it'll be gas before long.

 

[Budnicks]

Damn 19 & 25mpg, I don't get that even rolling down hill, coasting in neutral, loaded or not... My old wore 295,000 mile out 95 Ram 3500 4x4 w/5.9ltr Cummins 3.54:1 gears, would get 17-19mpg average, my 98 Ram 2500 4x4 w/5.9ltr. Cummins w/35" M&S tires, much lighter rig, did marginally better, it had a jacked up pump, big Garret turbo, higher flow injectors, bigger Inter-Cooler, 4" into a 5" exhaust, 3.73:1 gears & 1000 ftlbs of torque & 650+hp, but that was also driving around in the San Joaquin valley around Sacramento Ca. kind of flat land, not the mountains like were I'm at now... Also we have a ton of additives {EPA Ca. Reg. stuff, doesn't help the mileage "I'm sure"}, extra refining & costs in our diesel here in Calif....

 

[Cranky]

I know a guy that gets better than mine but he also drives slower.....never gets over 60 on the freeway and in town, you don't even want to follow him unless you want to go to sleep. I can just imagine the carbon buildup in that engine lol. Mine runs better if I don't drive it slow and blow it out from time to time.