Hello again!
I am going to throw this out to you guys who know a thing or 3 about
tire size and towing.You may not laught at any silly question I may
ask! I have asked 4 different tire dealers, Dodge dealer, and about
anyone else I could think of. I get different opinions and views and
suggestions. I know by throwing this question out, I will get more, but
I guess that's what I am looking for-more opinions! ok, here it is:
2004 Dodge Ram 1500 4x4 Quad Cab 5.7 Hemi 3.92 axle ratio 20 inch
tires
we are upgrading our travel trailer. My calculation is the most we will
pull loaded is 6500lbs. The truck is rated at 7500 with the 20 inch,
8500 if we put 17' on. We don't want to max out our weight by any means
and want to be good to the truck. On the Dodge printout I have it
shows our truck with 17" = 8500 lbs and with 20"=7500lbs.
Our current tires that came on the truck are p275/60r20 114s 44
psi 2601 lbs. Goodyear Wrangler Mud and Snow standar load (all the
info off the tire)
Here are suggestions I have gotten:
just change 20" to a different 20"- 27560r 20re 50 psi
2998 lbs. It's supposedly a better tire, has optimized thread, hiway
tread, extended wear, it's a Cooper Discover tire.This was from our
regular tire dealer who offered to sell 17" wheels and tires but said
why spend all that money when you can just put on different
tire.Hmmmm...true or does he need to move some inventory???
another: go to a 17" wheel and tire, it's the best way to go for
towing.I was all for this and started calling to get pricing, that's
when the controversy started.
another: if you switch to 17" you'll mess things up, brakes might not
line up,etc.
another:the above isn't true...
another: keep what you have, no need to change,you'll be fine.
another: go to a 20" 305/ 50/ 20 3100 lbs all terrain.
Spinning, my head is spinning...I'm so dizzy.... :-) I quit
calling around and decided I needed to use the forum again.
so plz, those of you with experience in this tire,truck,towing dept
....plz help! pretend the truck is yours and tell me what You'd do! I
want to really rely on the experience of others. Thanks for help! you
can answer here or email at iamtm@charter.net. Thanks again! Tawnya
GeekBoy - 23 Apr 2006 18:17 GMT
> Hello again!
> I am going to throw this out to you guys who know a thing or 3 about
> tire size and towing.You may not laught at any silly question I may
Well I had a '99 1500 with 16" wheels and V6. It was rated to tow 8900 lbs.
> ask! I have asked 4 different tire dealers, Dodge dealer, and about
> anyone else I could think of. I get different opinions and views and
[quoted text clipped - 42 lines]
> want to really rely on the experience of others. Thanks for help! you
> can answer here or email at iamtm@charter.net. Thanks again! Tawnya
Marc - 24 Apr 2006 01:40 GMT
You had a 1500 with a V6 that was rated to tow 8900lbs?? Yeah right.
>> Hello again!
>> I am going to throw this out to you guys who know a thing or 3 about
[quoted text clipped - 49 lines]
>> want to really rely on the experience of others. Thanks for help! you
>> can answer here or email at iamtm@charter.net. Thanks again! Tawnya
GeekBoy - 24 Apr 2006 06:15 GMT
> You had a 1500 with a V6 that was rated to tow 8900lbs?? Yeah right.
Yeah right. It came right off the Dodge web site.
>>> Hello again!
>>> I am going to throw this out to you guys who know a thing or 3 about
[quoted text clipped - 49 lines]
>>> want to really rely on the experience of others. Thanks for help! you
>>> can answer here or email at iamtm@charter.net. Thanks again! Tawnya
SnoMan - 23 Apr 2006 18:30 GMT
>Hello again!
> I am going to throw this out to you guys who know a thing or 3 about
[quoted text clipped - 45 lines]
>want to really rely on the experience of others. Thanks for help! you
>can answer here or email at iamtm@charter.net. Thanks again! Tawnya
Your 20's with a 3.92 is like towing with stock tires and a 3.55. The
best permanent fix here is to regear the truck. Install some 4.56's
(it is supported by ECM with reprogramming because some Power Wagons
came with 4.56's) It will offset tire size and make it tow a lot
better and ease strain on tranny. Do not take ratings as the gosphel
as some do as there is little science behind them (mostly marketing).
With 4.56 and 20's, you should be able to comfortably tow 8K or so
without beating the tranny to death with down shifts and towing MPG
will improve a bit too. When not towing your MPG will not take a hit
because 4.56's with 20's and OD will yeild a low cruise RPM in OD. (It
might actually increase MPG a bit under some conditions too)
-----------------
The SnoMan
www.thesnoman.com
clare at snyder.on.ca - 23 Apr 2006 19:13 GMT
>>Hello again!
>> I am going to throw this out to you guys who know a thing or 3 about
[quoted text clipped - 59 lines]
>-----------------
>The SnoMan
The 20 inchers he has are the same outside diameter an the 17's, I'd
suspect, so gearing is NOT the issue, and there should be no gearing
issues with brakes or ECU. I would NOT go to 4.56 gears at today's
fuel prices! I'd stick with the 3.92 gears and forgo overdrive when
towing.
As for the tires, a good FIRM tread (likely not a M+S) with strong
sidewalls is required. MOST of the 20 inch low profile tires are not a
good solution for trailer towing for sidewall reasons (what sidewall?
they are like a loll of friction tape) The best towing tire will be a
compromise when it comes to ride (but so is a Low Profile performance
tire) You want a tire that will not squirm, and a sidewall that will
stand up and not buckle with sideloads. My recommmendation would be a
good LT rated tire with a highway tread.17 inch would likely be the
best. May well cost less for tires and rims combined than a suitable
set of 20's to fit your current rims.
>www.thesnoman.com
SnoMan - 23 Apr 2006 23:45 GMT
>The 20 inchers he has are the same outside diameter an the 17's, I'd
>suspect, so gearing is NOT the issue, and there should be no gearing
>issues with brakes or ECU. I would NOT go to 4.56 gears at today's
>fuel prices! I'd stick with the 3.92 gears and forgo overdrive when
>towing.
That depends a lot on tire size on rim and if overall diameter is the
same then the the rim is 1 1/2 inches close to pavement which is not
good when you hit a chuck hole with a heavy load unexpectadly and loss
a rim. You want more rubber between rim and road. On gear ratio, there
is a false belief out there that taller gear equals better NPG towing
and this is not true most of the time, especail with a gas motor that
has a high RPM torque peak. There was a time when a 3.92 was a deep
gear but that was when cars or trucks weight 4 to 5K and had 29 inch
tires or so and no OD. Now they have 32's or so and can weigh over 6k
before you load them up and have OD as well to boot. If you are that
worried about MPG when not towing, buy a 4cyl to run around in. Also,
deeper gear will improve towing MPG with a heavy load, not hurt it
with a gas motor of that size as it is not the old low RPM stump
puller that the old V10 was.
-----------------
The SnoMan
www.thesnoman.com
.boB - 23 Apr 2006 20:38 GMT
> Hello again!
> I am going to throw this out to you guys who know a thing or 3 about
[quoted text clipped - 15 lines]
> psi 2601 lbs. Goodyear Wrangler Mud and Snow standar load (all the
> info off the tire)
The "problem" with the 20's is two fold. First, the 20" tires are not rated high
enough to tow/haul that kind of load. If you search around, you may be able to find
some that are. LT truck tires don't come in a 20" rim size - yet.
The second issue is the weight rating of the wheel itself. The 20" wheel is
mostly for show, and may not be made strong enough for real work.
The issue is NOT gearing. The overall diameter of the stock 17" and 20"
package is the same.
As I see it, you have two reasonable options. First, look around for a set of
new 17" take offs. You'll probably be able to find a set with only a few thousand
miles on them if you look around. Try an ad in your local paper or Thrifty Nickel.
Second, don't worry about it. Your plans are for 1,000 pounds less than rated
capacity. Even if your calculations are 500# off, you're still within specs. IMO,
the rated capacity is fairly conservative anyway.

Signature
.boB
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2001 Dodge Dakota QC 5.9/4x4/3.92
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Jay - 24 Apr 2006 02:09 GMT
>> Hello again!
>> I am going to throw this out to you guys who know a thing or 3 about
[quoted text clipped - 15 lines]
>> psi 2601 lbs. Goodyear Wrangler Mud and Snow standar load (all the
>> info off the tire)
With 3.92 Axle Ratio Axle Ratio You Can Tow 7500 lbs
Gross Vehicle Weight Rating (GVWR) = 6650 lbs
Payload = 1321 lbs
Curb Weight = 5329 lbs
Curb Weight Front/Rear = 3103 lbs/3103 lbs
GAWR Front/Rear = 3900 lbs/3900 lbs
Gross Combination Weight Rating (GCWR) = 13000 lbs
if you air up to 44psi both tires can handle 5,202 (you noted 2,601
above per tire) your axles are rated 3,900 each. You will over load the axle
before the tires. You are good to go.
But you can go with Avon Tyres (in the Cooper tires family) the Tech
ST 275/60 R20 are a 119S tire rated at 2,998lbs. at 50 PSI.
Personal experience, I have not towed with my 05 Ram 1500 QC 4x4 HEMI
20's But I've had enough wood in the back to bottom out the suspension and
aired up to 44 psi. with no problems for the tires.
Tom Lawrence - 23 Apr 2006 21:34 GMT
> another: go to a 17" wheel and tire, it's the best way to go for
> towing.I was all for this and started calling to get pricing, that's
> when the controversy started.
>
> another: if you switch to 17" you'll mess things up, brakes might not
> line up,etc.
A factory 17" wheel will fit without a problem (as that's what they come
with as standard equipment - you don't get bigger brakes when you opt for
the 20" wheels). However, many aftermarket 17" wheels will NOT clear the
brakes.
I agree with Bob... if it were me, (well, I wouldn't have gotten the 20's
in the first place, but that aside), I'd opt for a set of factory 17"
wheels, and get a good-quality load-range E tire (I'm partial to
Michelin's - always had good wear/performance from them) in 245/70R17.
That's just about a 31" tire, whereas your 275/60R20's are a 33" tall tire
(and P-rated at that - meaning the sidewalls are much weaker than an
LT-rated tire, especially an LRE tire). You'll need the dealer to
re-program your computer for the different tire size, but that won't be a
problem, because it's the stock size that comes with the 17" wheels.
I would absolutely NOT re-gear the truck... way too expensive, and
decreased fuel economy when running empty. Since your tire/wheel
combination is unacceptable for towing anyway, you'll get the same results
by downsizing your wheel/tire combo as you would by stuffing taller gears in
there.
You'll also be able to sell your 20's pretty easily, and offset a good
portion of the cost of the new tires/wheels. When it comes time for new
tires, you'll be saving even more, as the 17" truck tires are cheaper than
the 20" rubber bands (probably save over $100 on the set).