Silverado 4.8L, 3.23 Gearing

[2edgesword]

I've got a 2007 Silverado 4.8L with 3.23 gearing with the Tow Mode feature. The maximum towing specification is 4,700 lbs.

My wife and I are seriously looking at purchasing a Jayco 19RD which has a unloaded vehicle weight of 4,100 lbs. My understanding is the unloaded vehicle weight is the weight with standard equipment like AC, fridge, etc. but does not include water, propane, battery, WDH, sway bars, etc.

At this point we would be taking maybe six trips a year with the longest being a trip from NY to FL. We'd make the trips dry with no water in the tanks and the same sort of "stuff" we'd take if we were flying somewhere. For me that means 30 lbs and my wife 150 lbs . I'm think worse case is we would be right near the max of 4,600 lbs ~ 4,700 lbs.

Not to intentionally press the issue but I know that there is some safety margin factored in when the engineers design and create the published specifications.

My question is does anyone have an real world experience with towing under similar conditions described above?

I don't expect the TV to tow like a 5.8L or diesel but I do want to avoid getting bogged down only doing 40 mph on highway hllls. I'd rather not change the gearing since the vast majority of the driving (95%) I won't be towing anything.

I've read in other place "you'll hate the driving" to "it will handle this with no problems".

What say you?

[Denise]

This is just our experience; I'm no expert

Our tv (see signi) is rated to tow over 10k lbs. Our tt runs about 6900lbs loaded for a cross country trip. We drive 60-65 on flat highways. Hills slow us down to about 55-60. Grades reallllly slow us down to about 40-45 even with 'tow haul' mode on.

On the flats and hilly roads, our brakes work well. On the grades, we have to use the 'tow haul' mode so the engine helps slow us down otherwise we would be riding the brakes all the way down (the trailer really pushes our tv down).

You can see that even with an easy 3k pounds to spare, we still have concerns to be aware of. Our experience, we wouldn't tow at the max for our tv. Hope this helps some

[Seann45]

You of course have to factor in clothes food toys etc that you put in the RV. PLUS the weight of all passengers and anything else you have in the truck...
the industry standard is for a 150 lb driver if you weigh more than that also figure in the difference in your weight.

[Crabman]

Are you sure your truck is only rated 4700lbs? I can`t find anything that low for a 4.8 on this tow ratings site. Is it a manual transmission? That would lower it somewhat. This site is for the "classic" older style 2007 Silverado. http://www.cascaderv.com/Towing/07towratings.pdf

OK on edit I see that the NEW style 2007`s have much lower tow ratings then the "classic" 2007`s. I believe production changed mid model year to the new body style. So I`m guessing yours is the new body style with the lower ratings.

[2edgesword]

Originally Posted by Crabman

Are you sure your truck is only rated 4700lbs? I can`t find anything that low for a 4.8 on this tow ratings site. Is it a manual transmission? That would lower it somewhat. This site is for the "classic" older style 2007 Silverado. http://www.cascaderv.com/Towing/07towratings.pdf

OK on edit I see that the NEW style 2007`s have much lower tow ratings then the "classic" 2007`s. I believe production changed mid model year to the new body style. So I`m guessing yours is the new body style with the lower ratings.

Yep, the 4,700 lbs maximum trailer weight is right out of the owners manual for a 2007 Silverado, extended cab, 4.8L 3.23 axle ratio.

The GCVW for the Silverado as configured (engine and axle ratio) is 10,000 lbs. If you add the empty weigh of the TV (4,700 lbs) and start adding passengers, fuel and minimal cargo it looks like pulling even an empty 4,700 lb trailer would get me over the limit.

If I want to stick with my current TV I could switch to a 3.73 axle ratio which ups the maximum trailer weight to 6,700 lbs and GCVW to 12,000 lbs. Other then switch TV's altogether that may be the only option if we want to go with the 19RD.

[3Pillons]

It's your engine, tranny, and final drive ratio that is killing your towing capacity, not the truck chassis. It's not that it would be unsafe per se, it would just be very detrimental to your truck's performance and longevity.

[2edgesword]

Originally Posted by 3Pillons

It's your engine, tranny, and final drive ratio that is killing your towing capacity, not the truck chassis. It's not that it would be unsafe per se, it would just be very detrimental to your truck's performance and longevity.

Understood.

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 (maintaining highway speeds while towing would seem reasonable to me), and doing so with a high level of confidence that under these conditions the vehicle won't fall apart, at least while it is still under warranty .

I think my plan of action will be switching to the 3.73 axle ratio, which boast the tow limits to 6,700 lbs max. trailer weight and 12,000 lbs max. combined vehicle weight, and then rent a trailer of similar size/weight to see how the truck performs.

[clutch]

I would just add a large transmission cooler, keep it OUT of over drive, and tow with it. It all depends on how long you plan on keeping the truck and how much you want to spend on a 5 year old truck. Just putting a smaller size set of tires on will effectively lower your final gearing.

Just my opinion.

[29BHS ECO]

Be sure that your tires are rated for the heavier load that you will be hauling and yes you wi9ll be doing 40 mph on small grades. Larry ps don't forget, it is the wind resistance and not always the weight that slows you down.

[Seann45]

Originally Posted by 19H F250

Be sure that your tires are rated for the heavier load that you will be hauling and yes you wi9ll be doing 40 mph on small grades. Larry ps don't forget, it is the wind resistance and not always the weight that slows you down.

Make sure you dont have P rated tires they are not made for any trailer towing.

[2edgesword]

Originally Posted by Seann45

Make sure you dont have P rated tires they are not made for any trailer towing.

Can you provide more info regarding your statement "P ratd tires they are not for any trailer towing." I have P rated tires with a 2205 lbs max. load rating. Why would these tires not be good for trailer towing as long as I stay within the load rating of the tires?

[Bob Landry]

While LT tires give you a stiffer sidewall and a little better stability, there are a lot of people out there towing with P tires with few issues. That tow rating still seems a litle low to me. Is that with or without WD? Also, if you are going to re-gear the truck and keep it for a while a transmission cooler would be a good addition. That engine is going to work pretty hard and you'll probably been in the lower gears a lot.
I had a Toyota 4Runner with a V6 and no extra goodies that was rated at 5000lbs.

[Crabman]

3.73 rear and a tranny cooler looks like the best and cheapest fix. I`m using "P" tires also, I just air them up to the max (44psi) when towing and they do OK.

[2edgesword]

Originally Posted by Bob Landry

That tow rating still seems a litle low to me. Is that with or without WD?

As far as the hitch rating is concerned you can tow up to 5,000 lbs without or 10,000 lbs with WD.

As far as the engine and drivetrain are concerned you can tow up to 4,700 lbs.

In theory I could tow the 19RD (4,100 lbs) if minimal weight is added to the trailer, with the limiting factor actually being 4,700 based on the engine and gearing rather then the limit specified with respect to not having WD.

[Seann45]

Originally Posted by 2edgesword

Can you provide more info regarding your statement "P ratd tires they are not for any trailer towing." I have P rated tires with a 2205 lbs max. load rating. Why would these tires not be good for trailer towing as long as I stay within the load rating of the tires?

The side walls are to soft.... the first time you have to do an emergency maneuver you may find your tires roll right off the rims... HOW MUCH IS YOUR FAMILIES SAFETY WORTH TO YOU? Remember you not only have to factor in the weight of the trailer and tongue weight, but also anything in the truck... cargo and passengers.

[2edgesword]

Originally Posted by Seann45

The side walls are to soft.... the first time you have to do an emergency maneuver you may find your tires roll right off the rims... HOW MUCH IS YOUR FAMILIES SAFETY WORTH TO YOU? Remember you not only have to factor in the weight of the trailer and tongue weight, but also anything in the truck... cargo and passengers.

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.

Of course you can always select tires that exceed the anticipated load but making that selection based on the question "how much is your families safety worth" becomes a subjective question that doesn't have a satisfactory answer if, as most of us believe, no monetary value can be assigned to our family.

This comment isn't meant to be argumentative but having worked in engineering (electronics) for the last 25 years (some of that experience has been working with engineers from the major automobile companies) I like to deal with specifications and test data rather than anecdotal evidence. 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.

[Crabman]

Another consideration with moving up to LT tires on a 1500 series truck is that the wheels may not be rated for the 60 to 80 psi with LT`s so you may have to replace all your wheels and tires, and you would get a harder ride then you are used to when not loaded. No doubt they are designed to carry more weight and would likely perform better. But since the trailer is not that big or heavy I would try the P`s first and see how they do. Upgrading to LT`s later will still be an option if you feel it is necessary after a few trial runs........

[Rustic Eagle]

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.......snip

Your correct about carrying a a particular load safely, but that is based on the TV loaded weight only...., not the additional 5,000lb to 10,000lbs being towed behind it.

The weight of the TT being towed behind the TV can influence how TV tires react under certain towing conditions (TV turns, sudden stops, cross winds, passing vehicles, sway event, etc.). Having additional plys in the tire sidewall reduces sidewall "give", thus providing added TV handling characteristics when towing. Most "P" rated tires have only a 2-4ply sidewall, where "LT" tires commonly have 8-10 ply sidewalls. The "P" rated tires will give you a softer and adequate ride performance, which is fine for 95% of the Trucks and SUV's which never tow a TT.

Bob

[poohbear]

You upgrade one thing,that stresses another,upgrade that & now you need this.A good used truck with heavier motor/tow capacity might end up cheaper than all the upgrades this could involve.

[2edgesword]

Originally Posted by Rustic Eagle

Your correct about carrying a a particular load safely, but that is based on the TV loaded weight only...., not the additional 5,000lb to 10,000lbs being towed behind it.

First, I have zero insight into how the major automakers establish their published specifications.

On the other hand, since they do publish towing specifications, I have to believe that some consideration and testing went into establishing the specifications they publish, especially given our litigious society. 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?

Originally Posted by Rustic Eagle

Having additional plys in the tire sidewall reduces sidewall "give", thus providing added TV handling characteristics when towing. Most "P" rated tires have only a 2-4ply sidewall, where "LT" tires commonly have 8-10 ply sidewalls. The "P" rated tires will give you a softer and adequate ride performance, which is fine for 95% of the Trucks and SUV's which never tow a TT.

Understood.

And I'm also not saying that the auto companies don't make mistakes or that they are beyond reproach. I am one of the Toyota owners subject to the brake, floormat recalled .