Silverado 4.8L, 3.23 Gearing

[Rustic Eagle]

Originally Posted by 2edgesword

snip.......How do you publish a maximum allowable trailer tow weight without testing and data on how towing a trailer of that weight will impact the drivetrain, chassis and tires of the TV, and more importantly, safety of the vehicle?.....snip

Great thought provoking question for an open disscussion.., but IMO only the TV manufacture could shed viable light on the subject.

As you are aware, the subject of manufacturer's publicized "tow ratings" is a hot topic in about every RV forum one could 'google'... , the latest of which is "How can a manufacture raise the tow rating of a new model year vehicle when the vehicle is identical in every way to the prior model year?"

Since you mentioned published tow ratings, you may find this interesting: http://www.jaycoowners.com/showthread.php?t=3866

Bob

[2edgesword]

Originally Posted by Rustic Eagle

Great thought provoking question for an open disscussion.., but IMO only the TV manufacture could shed viable light on the subject.

As you are aware, the subject of manufacturer's publicized "tow ratings" is a hot topic in about every RV forum one could 'google'... , the latest of which is "How can a manufacture raise the tow rating of a new model year vehicle when the vehicle is identical in every way to the prior model year?"

One of the ways this can occur is as the result of further in-house testing and/or feedback from end users. The initial specifications might be published based on X number of hours of test. If a model remains basically unchanged and additional testing has occurred the data accumulated from that additional testing may result in an increase or decrease in the published specifications.

Originally Posted by Rustic Eagle

Since you mentioned published tow ratings, you may find this interesting: http://www.jaycoowners.com/showthread.php?t=3866

Bob

Good information.

[Seann45]

Originally Posted by Rustic Eagle

<snip>Great thought provoking question for an open disscussion.., but IMO only the TV manufacture could shed viable light on the subject.

"How can a manufacture raise the tow rating of a new model year vehicle when the vehicle is identical in every way to the prior model year?"

Bob

They electronically re-tuned the engine to keep up with the competition.

[Denise]

Originally Posted by 2edgesword

I understand the various weight factors but I'm not understanding your comment that the tires are "too soft" if they have been designed to safely carry a particular load..

Good for you! Keep asking what you don't understand even when your question is answered with a vague response. There are quite a number of members here that share their knowlege/expertise about the different topics that pop up. Out of all the member replies, there will be a couple that 'get' your question

Originally Posted by 2edgesword

. If the vehicle and tire manufacturers understand that a product is going to be subject to various loads during normal and emergency use I would think those considerations would have been factored into establishing the published specifications.

I hear ya.... Go figure why Ford (or any other company) would put P tires on a truck with heavy duty tow package designed to tow more than 10k lbs. But, it happens.

Here's our experience.... When purchasing a 1/2 ton to use with a "lite weight" tt (we hadn't bought yet), I poured over every tire site and forums that had anything to do with towing and tires (got the head's up on tires perusing another rv forum prior to buying the truck).

We asked the dealer about changing out the tires before we take delivery as we were going to tow over 5k-6k miles a year in all kinds of road conditions. The guy said don't worry as manufacturers wouldn't install P rated tires on a towing vehicle if it wasn't ok (he also pointed out that our 'bling 20" wheels look way cooler for a Platinum). I then made phone calls to every tire shop in our area... the all said to go with the smaller 18" wheels at least and get the LT tires! I even asked the service manager what he thought. He agreed with the tire shops!

[2edgesword]

Originally Posted by healthi

Here's our experience.... When purchasing a 1/2 ton to use with a "lite weight" tt (we hadn't bought yet), I poured over every tire site and forums that had anything to do with towing and tires (got the head's up on tires perusing another rv forum prior to buying the truck).

We asked the dealer about changing out the tires before we take delivery as we were going to tow over 5k-6k miles a year in all kinds of road conditions. The guy said don't worry as manufacturers wouldn't install P rated tires on a towing vehicle if it wasn't ok (he also pointed out that our 'bling 20" wheels look way cooler for a Platinum). I then made phone calls to every tire shop in our area... the all said to go with the smaller 18" wheels at least and get the LT tires! I even asked the service manager what he thought. He agreed with the tire shops![/SIZE]

I do want to play it safe which is why I'm taking a hard look and have a mindset to stay within the manufacturer's (TT, TV and tires) specifications.

Of course I'm also considering going the extra mile (upgrades) with the understanding that if you change one thing (switching to LT tires) it will have a bearing on other things (total weight, higher tire pressures, ride, fuel economy, etc.). It also is difficult in some cases to quantify the cost/benefit minus using the catch all phrase "what is the life of your family worth". I also have to consider that for now towing will be a six or eight times a year event factored that into the decisions I make.

Anyway, I appreciate all the comments and advice. It gives me food for thought and has opened the window to understanding the various alternatives.

[SmokerBill]

I have Goodyear P265\R17 tires on my new truck, and even though it seemed to handle fine on my last pull (about 800 miles) and the tires don't seem to squash out when the trailer is hooked up, I sent a message to Goodyear asking if my tires are suitable for towing applications. I'll post back if they ever return with an answer.

[2edgesword]

Originally Posted by SmokerBill

I have Goodyear P265\R17 tires on my new truck, and even though it seemed to handle fine on my last pull (about 800 miles) and the tires don't seem to squash out when the trailer is hooked up, I sent a message to Goodyear asking if my tires are suitable for towing applications. I'll post back if they ever return with an answer.

Look forward hearing the response from Goodyear.

[Rustic Eagle]

Originally Posted by 2edgesword

snip.......I'm pretty sure the engineers at GM set the towing limits based on being able to safely go to those limits with reasonable performance.......snip

2edgesword,

We know that your manufacturer's publicized tow limit of 4,700lbs will be degraded to an "actual" tow limit, and this value can be confirmed (reference 'sticky' link provided in earlier reply).

Ok.., "Performance",

Just thinking out loud here.......; Lets assume that your TV is towing at it's maximum "actual" tow rating (lets say 4,400lbs)...., depending on "what" is being towed (flat bed trailer, boat, TT, etc.) weighing in at 4,400lbs may impact the TV's towing performance. Since we all drive differently, the performance impact may vary from one person to another as well. Now, having said that.......,

The fact that a TT has a notable frontal drag (above that of the TV) it would have the highest potential of compromising the towing performance of your TV with a 4.8L/3.23 gear in less than ideal conditions. Ideal conditions would be towing on the flat without any head/cross winds.., less than ideal would be long grades, mountains, head/cross winds, etc..

Bringing my thoughts together...........; Your personal towing speed expectations will have a direct impact how much TV power it will take to overcome the frontal (aerodynamic) drag of the TT. From a physics standpoint speed becomes the variable that will influence the performance impact (do to TT drag), and knowing that a lower speed reduces the drag impact on performance, the 3.23 gearing may then become the weak link in less than ideal towing conditions, thus impacting performance as well.

I guess I'm attempting to get into the head of an automotive powertrain engineer , and address your original post from a different vantage point.

Bob

[clutch]

Referring back to post #8. Try it with just a cooler and see if it comes close to your expectations. Either you will be ok with it or you will be shopping for a truck with a bigger engine.

[2edgesword]

Originally Posted by Rustic Eagle

2edgesword,

We know that your manufacturer's publicized tow limit of 4,700lbs will be degraded to an "actual" tow limit, and this value can be confirmed (reference 'sticky' link provided in earlier reply).

I'm not sure if the word "degraded" is accurate. The tow rating is what it is. The issue is understanding what things should be considered when determining the load.

Originally Posted by Rustic Eagle

Ok.., "Performance",

Just thinking out loud here.......; Lets assume that your TV is towing at it's maximum "actual" tow rating (lets say 4,400lbs)...., depending on "what" is being towed (flat bed trailer, boat, TT, etc.) weighing in at 4,400lbs may impact the TV's towing performance. Since we all drive differently, the performance impact may vary from one person to another as well. Now, having said that.......,

Our perception of performance, based on our personal experience, will be different but given a particular load, regardless of who steps on the accelerator or brake, if we apply the same pressure we"ll get the same results.

Originally Posted by Rustic Eagle

The fact that a TT has a notable frontal drag (above that of the TV) it would have the highest potential of compromising the towing performance of your TV with a 4.8L/3.23 gear in less than ideal conditions. Ideal conditions would be towing on the flat without any head/cross winds.., less than ideal would be long grades, mountains, head/cross winds, etc..

The aerodynamics of the TT and TB will have a bearing on performance. Of course aerodynamic drag increases dramatically with increased speed so a slight moderation in speed will result in a significant reduction in drag.

Originally Posted by Rustic Eagle

Bringing my thoughts together...........; Your personal towing speed expectations will have a direct impact how much TV power it will take to overcome the frontal (aerodynamic) drag of the TT. From a physics standpoint speed becomes the variable that will influence the performance impact (do to TT drag), and knowing that a lower speed reduces the drag impact on performance, the 3.23 gearing may then become the weak link in less than ideal towing conditions, thus impacting performance as well.

My expectations at this point are that I will be able to accelerate to highway speeds so that a safe transition can be made and handle typical highway grades found in my area without having to slow to 30 mph. I don't expect super acceleration and 75mph speed uphill when towing but rather performance that would allow safe traveling on the majority or roads.

I don't know the various types of loads the TV manufacturers consider when establishing tow limits but in this age of computer simulation I would think they consider all sorts of loads including aerodynamic load when determining a maximum trailer load. Some feedback I've received from a TT owner with a similar set-up to what I am consider is he has had acceptable performance on highways and moderate grades.

We shall see

[Rustic Eagle]

Originally Posted by 2edgesword

snip........ Some feedback I've received from a TT owner with a similar set-up to what I am consider is he has had acceptable performance on highways and moderate grades. We shall see

Sounds like the feedback from the other TT owner addressed your original question..., let us know if you find the performance towing the 19RD acceptable as well.

I can only summarize by saying confirm your TV's "actual" tow rating, and the 19RD's actual "ship weight" (higher than UVW 4,140lbs).

Bob

[2edgesword]

Originally Posted by Rustic Eagle

I can only summarize by saying confirm your TV's "actual" tow rating, and the 19RD's actual "ship weight" (higher than UVW 4,140lbs).

Bob

I'm sure you're correct and at some point I'll do the only thing that will tell the true tale, weigh them both in trip configuration.

Another issue is maximum hitch and axle weight. While switching gear ratio increases the maximum trailer weight to 6,700 lbs and the maximum combined vehicle weight to 12,000 lbs, the hitch maximum with WD is only 10,000 lbs.

The maximum axle weights are 3,600/3,950 (front/rear) so if I attempted to tow a 6,700 lb trailer (15% tongue weight) with a truck loaded to the max (I think the maximum gross weight 6,400 lbs) I'm pretty sure the rear axle weight limit could be exceeded.

[SmokerBill]

Originally Posted by 2edgesword

Look forward hearing the response from Goodyear.

Goodyear Consumer Relations just responded to my query:

Sent by: Goodyear Tire & Rubber Company Consumer Relations 728 1144 East
Market Street Akron, OH 44316 Voice #: 800.321.2136 Fax #:
330.796.6829

Thank you for contacting our website.

The P265/70R17 Goodyear tire that came original on your 2011 Ram 1500 is
either the Wrangler SR-A, or the Wrangler HP. Both of these tires would be
suitable for towing, when towing we recommend inflating the tires to the
max inflation. The air pressure indicated on the sidewall of each tire is
the max inflation pressure.


Daniel T. Gibbs
Consumer Relations

My truck is equipped with the Wrangler SR_A tires, and I do make sure to inflate them to the maximum pressure (44 pounds) when towing. With my previous truck, the 2500 Ram CTD, the rear tire pressures maxed at 80 pounds, so I've been somewhat concerned about the lower pressure tires I have on my truck.

I know I'm not even getting close to their rated weight load (2535 pounds each). My truck weighs right at 5500 pounds with me in it and full of gas. When towing the trailer my total payload (minus the 150# allowed for the driver) is no more than 300 pounds, since I load most everything in the trailer.

Add to that a tongue weight of about 900 pounds, I'm well below the maximum payload for my truck of 1529 pounds. My TT is more than 20% under the maximum towing weight.

Even though I'm sure that using "LT" rated tires instead of the "P" rated tires I have would offer a more stable ride, I feel confident that my tires are completely adequate for my towing needs.

Bill

[Crabman]

Originally Posted by SmokerBill

Goodyear Consumer Relations just responded to my query:



My truck is equipped with the Wrangler SR_A tires, and I do make sure to inflate them to the maximum pressure (44 pounds) when towing. With my previous truck, the 2500 Ram CTD, the rear tire pressures maxed at 80 pounds, so I've been somewhat concerned about the lower pressure tires I have on my truck.

I know I'm not even getting close to their rated weight load (2535 pounds each). My truck weighs right at 5500 pounds with me in it and full of gas. When towing the trailer my total payload (minus the 150# allowed for the driver) is no more than 300 pounds, since I load most everything in the trailer.

Add to that a tongue weight of about 900 pounds, I'm well below the maximum payload for my truck of 1529 pounds. My TT is more than 20% under the maximum towing weight.

Even though I'm sure that using "LT" rated tires instead of the "P" rated tires I have would offer a more stable ride, I feel confident that my tires are completely adequate for my towing needs.

Bill

That`s one thought I had with the P tires, you would already exceed the trucks RAWR and GVWR well before going over what the tires are rated for.

[2edgesword]

Given all that has been mention it sounds like the challenge is understanding where the weakest link is with a particular TT/TV combination.

In my situation even if I changed the gearing to 3.73 and utilize a WDH to increase the maximum trailer and combined vehicle weight to 6,700/12,000 I couldn't enjoy the benefit of these increases given the limit on the rear axle weight (3,950 lbs), hitch limit (10,000 lbs) and maximum tire load (2,250 lbs).