3:73s or 4:10s in new truck

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tvfrfireguy

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I will be ordering a new tow vehicle (Chev) soon. I read in the latest Trailer Life towing guide that 4:10 rear end gears are the way to go.  Our 5th wheel is 11,750 lbs. dry.  Does this gear change make that big a difference in the fuel bill?  Thanks so much in advance. Dave
 
It's not just the rear end ratio, but the whole package, including what type of driving you do (flat, hills, mountains?) (50, 60, 70 mph?) that will determine the best engine/gear combination for you. There are no hard and fast rules but, generally speaking, an engine will require less service when run at lower rpm's. How hard and how often you 'stick your foot in it' will have an adverse effect on mileage. Maybe others can be more precise in their answer.
 
Fuel mileage stinks in an overstressed two vehicle, go with the ratio indicated by the tables.

I note that the 11,750 is a dry weight.  That is essentially meaningless.  What needs to be used is the Gross Vehicle Weight Rating (GVWR) of your 5er.   You can find that number on the DOT plate on the left, driver's, side of the trailer at the forward end.   It is the dry weight plus the carrying capacity of the trailer.

Buy a tow vehicle with a tow rating equal to that number plus a 10% safety factor for a diesel.   (20% for a gasser in the far west.)
 
The GVWR of our 5th wheel is 14,999 lbs.  We live in Oregon and mountains are everwhere we go.  We usually cruise along at 60 mph tops.  I thought someone reading this may own a one ton Chevy duramax with 4:10 gears and could let me know if it makes a difference.  I have looked at units on the dealer lots and they all come with 3:73 gears.  4:10s are most likely a special order item.  Any dealer incentives would probably be gone if one special orders their truck.  I am interested in longevity and the proper equipment to pull our rig.  When I talk to the sales people, they seem clueless to my enquiries.  After following this forum for a year or so, I know this is where I will find my answers.  Thanks,  Dave
 
tvfrfireguy said:
The GVWR of our 5th wheel is 14,999 lbs.  We live in Oregon and mountains are everwhere we go.  We usually cruise along at 60 mph tops.  I thought someone reading this may own a one ton Chevy duramax with 4:10 gears and could let me know if it makes a difference.  I have looked at units on the dealer lots and they all come with 3:73 gears.  4:10s are most likely a special order item.  Any dealer incentives would probably be gone if one special orders their truck.  I am interested in longevity and the proper equipment to pull our rig.  When I talk to the sales people, they seem clueless to my enquiries.  After following this forum for a year or so, I know this is where I will find my answers.  Thanks,   Dave
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You will need a turbo diesel truck with at least a 16,700 lb tow rating.  .  In 2008, the closest that Chevy comes to that is the regular cab 4wd 3500 regular dually with the 6.6TD and a 3.73 rear end.  [trailer Life 2008 Tables]  There is no rating for the 4.10 which makes me suspicious that Chevy does not offer that option for the 3500 diesel.

I do not want to get in religious arguments here, but with that trailer you may have a Ford in your future.  Specifically the Ford F-450 Super Duty Crew Cab with the 6.4L TD and the 4.01 or 4.88 rear end.

Hate Fords?  Look to medium duty trucks.  You might want to take a look at them anyway -- ones like the Peterbuilts and Volvos.  You have definitely edged over into their range.  Especially in Oregon.  (Think Siskyou Pass)
 
If you can get the 4.10's in the Chevy, it will definitely be the way to go.  It will make very little difference in the gas mileage you get (1 - 3 mpg at best...or worst), but it will definitely make your pull easier.  I think I would have to agree with Carl though.  That's a bunch of trailer you're gonna be pulling.  I've heard a lot of good stuff about the new 08 F-450.  Properly equipped (with the Tow-Boss package and 4.30 or 4.88 gears), it is a beast of a truck.  It is worth looking at even if you are a die-hard Chevy man.
 
Chevy does not offer a 4.10 in the duramax.  It makes it's power in a low enough rpm and with the allison you don't need it.  I'm not sure about the trailer's loaded weight, but I have a good friend that pulls a 44ft. gooseneck enclosed car trailer with his duramax 3.73 geared Chevy.  Has no trouble what so ever.  I would guess the weight to be in the 12-14,000lb range.
 
I have a 2005 Duramax and love it's pulling power.  My truck is rated at 15,600 towing capacity.  Chevy does not offer the Duramax with 4:10 gears.  If you want to know about price and options you can go to the Chevy "build and price"  (http://www.chevrolet.com/byo/build.cv?year=2008&make=Chevrolet&makeId=001&model=Silverado&modelId=003 ) web page to see the available options and prices.

I priced mine first at the Chevy page, then shopped around on the web a bit.  Bought mine from carsdirect.com for substantially less than the Chevy MSRP.

Good luck on your search.
 
Thanks for your replies.  You guys are great!  My rig is 34ft long and I see lots of three quarter tons pulling trailers much larger than mine.  I just want to be safe and have stability.  I will check out this on line dealer but plan on using the Consummer Reports service (that costs about twelve bucks) that gives you the lowest price the dealer in your area will take.  Have any of you guys used this service?  Dave
 
tvfrfireguy said:
Thanks for your replies.  You guys are great!  My rig is 34ft long and I see lots of three quarter tons pulling trailers much larger than mine.  I just want to be safe and have stability.  I will check out this on line dealer but plan on using the Consummer Reports service (that costs about twelve bucks) that gives you the lowest price the dealer in your area will take.  Have any of you guys used this service?   Dave
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Over at the top of the Trailers section therei is a topic on why we are concerned about tow ratings.  That little car likely pulled that trailer a fair distance passing a number of folks who saw him getting away with it until he got to that hill.  Your talier could be pulled by a half tonner...on the flats....for a while.. until the transmission went west....until the brakes burn up on a down grade... or the engine boils over on an upgrade.    Seeiing it rollinig down the highway under favorable conditions, you might well thing that Chevy 1500s could pull a 34 foot trailer. 

Length of trailer means very little in towability.  Weight means everything.  The best of 3500s I see on the Trailer Life would be a submarginal tow vehicle for your unit -- especially in the mountain and Pacific West. 

 
RV Roamer said:
He doesn't need a Peterbilt. If he is a Chevy guy, a Chevy Kodiak diesel will do the job nicely. Similar capability to the F450/F550 range.
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Yup, and I would emphacize, the Kodiak is a medium duty truck like the Peterbuilts and Volvos I mentioned.
 
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