Welcome to the forum and to the world of Towing an RV !!!
Glad to hear you are researching before jumping in...too many jump in
and then find that they have the wrong setup and/or marginal setup
First, decide if you believe in the OEM's ratings system and numbers
If not, then academic and do whatever you wish, but note that the OEMs
are now off the warranty hook (if any left) and liability hook
If yes, research, read up and gather info to do the simple math to
figure. The best is to actually weigh the whole setup fully loaded
ready to go RV'ing. Weigh it axle by axle
Comments embedded in red below
ricks99 wrote:
Wife and I are longtime tent-campers trying to upgrade to a travel trailer. We're looking at something in the 15-17' range (such as Starcraft AR-One, R-Pod, etc.) weighing under 3,000.
Since my current vehicle (Ford Fiesta) wont tow *anything* I know I need to get a truck capable of safely towing a camper. I've tried to do my homework, but I'm going crazy...GVWR...GCW...axle rating...tongue weight...gear ratio...transmission coolers...
GVWR.....Gross Vehicle Weight Rating...AKA max rated weight on the pavement
This applies to any DOT approved/registered vehicle...including the trailer
Derived from a 'curb' TV weight and the MTWR (Max Tow Weight Rating)
for the largest trailer this TV is rated to tow. "Curb" is the stripper
model TV with NO options, except for the 'tow option' and one 150LB driver
GCWR....Gross Combined Weight Rating...both TV and trailer
TV....Tow Vehicle
GAWR....Gross Axle Weight Rating...there are two, Front and Rear that
the axle is rated for. Most times the front and rear added together do
NOT equal the GVWR and is something we outside of the OEM design team
will never know how they derived their GVWR
MTWR....Max Tow Weight Rating...is the largest trailer a 'curb' weight
TV is rated to tow. Too many think of this rating in an absolute term.
Meaning that if their TV is loaded up to it's GVWR before hooking up,
their TV is rated for that....NOT SO, if loaded to their GVWR there is
NO MORE RATING for the tongue & hitch weight
I've seen plenty of trucks in my price range ($10K) that I *think* will work (F150, Excusion, Silverado 1500, Yukon) but I've been unable to make an exact determination. The sellers sometimes have no idea what gear ratio the truck has. Or if the installed hitch is a "load distributing" hitch. Etc.
Suggest using their GVWR's to reference between them. Example is that
you are comparing 'half ton' to '3/4 ton' and that a Silverado can be
either a 'half ton' or a '3/4 ton'. Ditto a Yukon, there are two of them
An Excursion was never sold in a 'half ton' model
Ford (other too) has over 12 F150 (half ton) models. IIRC, ranging
from low 6,000 lbs to just under 8,000 lbs...they used to have an 8,1000
lb GVWR F150
Most all of a TV's have their loaded weight placed on their rear axle
Just look at their side views and that most will have the rear edge
of the drivers door near dead center. Loading is most always behind
the drivers seat
'Half ton' TVs generally have a rear GAWR in the 4,000 lb range. Next
higher class TVs generally have a rear GAWR in the 6,000 lb range. That
approx 2,000 higher ratings provides for larger tongue weight and loaded
stuff in/on the TV
Buying used has the potential that the previous owner(s) changed out
the diff gears. Below is a method to figure that out.
Just checking the option label and/or the tag on the diff only tells
you what that vehicle left the factory with
The part bolted to the TV's rear for towing is the 'receiver' that
has a square tube (some call it the receiver pin box) that holds the
'shank'/'draw bar', which holds the ball or WD Hitch
The part on the trailer that goes on the ball is the coupler (if you
already know this, then it is for the lurker newbies)
With the small size trailer we're looking at, can I safely assume that nearly any full-size vehicle with a V8 will work? Is there anywhere online that I can simply plug in a vehicle VIN and get a "you can safely tow XXXXX" determination?
The link provided is a good source, but best if from the OEM
Roll the vehicle so that one wheel valve stem is straight down.
Tape length of string on the drive shaft pointing straight down
Roll the vehicle one rotation so that the valve stem is again straight
down
Count the full number of string wraps on the drive shaft. That is the
first full number of the diff ratio. If 3 full wraps, then it is 3.X ratio
The fraction of string wrap is the second part of the diff ratio. So
if about 3/4 of a wrap/turn, the diff ratio is 3.73
Remove the string
