towing capacity question

[gkrenzer]

I currently drive an 05 trailblazer ext with the I6 engine. I have the opportunity to purchase an 04 envoy with the v8 engine. Mileage is roughly the same for both vehicles and the $ is right.
I am, however, finding ambiguous info about the towing capacities of both vehicles. This is a concern as I just purchased a travel trailer that weighs 4200 empty. By the time i load 3 kids and stuff I will be hauling much more than that.
In some places (internet) the V8 is actually listed with a smaller towing capacity than my I6 rated around 6000. That just doesn't make sense to me. So I thought I would start at the beginning.

What do I need to know my current towing capacity (gear ratios, tranny coolers, suspensions etc) and where do I look to find them. I want to confirm what I have.
Then how do I figure it out for the new vehicle with the V8?

thanks in advance...

 

[The_Roadie]

Gear ratos are a code on your glovebox RPO sticker.
GT4 = 3.73
GT5 = 4.10
GU6 = 3.42

Towing capacity is limited by the brake specs, not the engine. So a heavier vehicle caused by the V8 or by adding the 4WD system can have lower ratings than a 2WD I6. That's the reason it seems backwards.

All of our vehicles have a small built-in transmission cooler, so that's not the rating limit. HOWEVER adding a $50 Hayden cooler or equivalent is highly, highly recommended to preserve your tranny lifetime. There are plenty of discussions here about aftermarket coolers.

The tow ratings charts for each year are widely available with a Google search, or are also in the Owner's Manuals. And as you probably know, purchasing and properly setting up a weight distributing hitch is mandatory at those weights.

 

[Dad-O-Matic]

I currently drive an 05 trailblazer ext with the I6 engine. I have the opportunity to purchase an 04 envoy with the v8 engine. Mileage is roughly the same for both vehicles and the $ is right.
I am, however, finding ambiguous info about the towing capacities of both vehicles. This is a concern as I just purchased a travel trailer that weighs 4200 empty. By the time i load 3 kids and stuff I will be hauling much more than that.
In some places (internet) the V8 is actually listed with a smaller towing capacity than my I6 rated around 6000. That just doesn't make sense to me. So I thought I would start at the beginning.

What do I need to know my current towing capacity (gear ratios, tranny coolers, suspensions etc) and where do I look to find them. I want to confirm what I have.
Then how do I figure it out for the new vehicle with the V8?

thanks in advance...

Here's what the owners manual says. As Roadie stated, check the RPO code from the glovebox to get axle ratio and reference the chart below to get the towing capacity.

Edit: this chart is for 2004 Envoy

View attachment 33695

 

[gkrenzer]

Thanks. I will look this up as soon as I am off work.
I assume this same (exact) table will be in the owners manual of my 05 trailblazer ext???

 

[DocBrown]

Or a similar chart. Keep in mind that even if you assume best case scenario that the V8 has the 3:73 gears and is 2WD, you'll be pushing the limits of that Envoy. And your kids will grow, get heavier and want to bring more and heavier toys.

Never, ever look at the dry weight of a trailer. It's a fictional number. No trailer leaves the factory at that weight. Its does not include options. Two numbers to be aware of are the shipped weight, in other words, what it weighed when it left the factory. A more important number is the GVWR, the max the trailer can weight with the full payload used. I suspect your trailer's GVWR is somewhere around 5500# - 6000#. That eats up your Envoy's cargo capacity real fast and doesn't leave much wiggle room for the family.

You might want to be looking at 2500 Series Suburbans. All I'm saying is that this is probably doable, but I know from experience that you'll be looking for a different tow vehicle after one season or so. I just bought the truck listed in my profile, in part because my TB was OK to tow my 4750# GVWR trailer with, but it certainly was not the best thing to pull with because I was also pushing the capacity. And it certainly was not up to towing my trailer through mountains or hilly country.

 

[Robbabob]

As awesome as these trucks are for their size, they just can't do everything.

You'll need to consider going up in platform to handle the new load of the trailer. If you'll only be using the trailer a few times per year, consider using rental cars for the towing. Then, you keep your daily driver... the TB with better gas mileage!

Good luck!

 

[DocBrown]

Then, you keep your daily driver... the TB with better gas mileage!

Good luck!

I've learned that's not quite accurate. I get the same with the TB as I got with our '95 Suburban, maybe 1/2 mpg better. But that's all. It was a big dispointement when we bought the TB 8 years ago. I wasn't expecting sedan type mileage, but I also expected a couple of mpg better.

In just the first few days of driving the Sierra we're getting 15.5 in the city. That's about the same as I get with the TB. And I have to be very disciplined with the TB to get that good in the city.

 

[gkrenzer]

Update:
After work I found the towing capacity for both vehicles based on the info provided by everybody above. (Thanks!) My TB is able to haul 5300#. The envoy is rated for 6300#. Upon inspection, the trailer GVWR is 4950. That is way too close for comfort for the TB. A Better fit for the Envoy even considering the family and I am leaning that way (especially since it will likely be an even trade and no money out of my pocket).
I suppose this conversation could ultimately evolve to one discussing what vehicle would be ideal. My answer to this and probably felt by all serious haulers as well: YOU CAN NEVER HAVE TOO MUCH HORSEPOWER AND TORQUE WHEN IT COMES TO TOWING. I will probably offend somebody by saying that but...

That said, does anybody know the (approximate) towing capacity of the Tahoe/Yukon or the Suburban?

 

[DocBrown]

That depends on the age and gearing of the Tahoe/Suburban. Before we bought the Sierra, we looked at a 2008 'Burb with 5.3 and 3:73 gears. Towing capacity for that truck is 7000#. Keep in mind that 'Burbs and Tahoes come with high price tags. An older pre '07 'Burb doesn't have much better towing capability than the GMTs do.

You'll be fine with that trailer and the Envoy. The GVWR of that trailer is much lower than I expected. But in a couple of years you'll want or even need an upgrade as your kids get bigger. One other thing to consider is the low cargo capacity of the trailer. Look for a yellow sticker on the street side of the trailer and look for the "Weight as Shipped". Subtract that number from the GVWR and you'll know how much you can put in it. It's probably going to end up being between 500# and 700#. With 3 kids, that's not a lot of wiggle room. You don't want to blow tires or damage the trailer axles due to overloading. That makes for really bad camping trips.

 

[linneje]

I have a 5.3L Envoy XL with the 3.73 axle ratio and own a 5400 lb trailer dry weight. Everyone asks me in the campgrounds how the Envoy pulls it, and I tell them the truth - easy. And I have pulled it in some high prairie winds, a few steep grades without a problem, but I do have sway control and a weight distribution hitch.

So, yes, the 5.3L envoy can do it for you. Mileage isn't great (about half of what it gets without towing), but that is to be expected. If you buy it, remember to always tow in 3rd. Check out the URL if you want to compare with other possible tow vehicles.


Trailer Towing Guides | Trailer Life Magazine

 

[Ghoster]

That depends on the age and gearing of the Tahoe/Suburban. Before we bought the Sierra, we looked at a 2008 'Burb with 5.3 and 3:73 gears. Towing capacity for that truck is 7000#. Keep in mind that 'Burbs and Tahoes come with high price tags. An older pre '07 'Burb doesn't have much better towing capability than the GMTs do.

My 2011 Tahoe was 8200 lbs. It had the 3.42 gearing and the HD cooling options. You really have to look close at the GM products to figure out the factory specs. The HD cooling options could be added later with aftermarket parts.... so does that mean that any 3.42 geared Tahoe could do it? Who knows. The 3.73 gears were only available in the 2500 series in the 2011 on up models.What are the specs on your Sierra?

 

[DocBrown]

What are the specs on your Sierra?

For 2008 there were only 2 gear options available for the Crew Cab, 3:73 and 4:10. With the 5.3, its 7500# for the 3:73 gears, and 8500# for the 4:10. I still need to look up the RPO codes to find out which gears I have, and if I have the MAX Trailering Pack. I bought it from a Ford dealer so they didn't know.


I can tell you that in the mid '90s, a Tahoe with 3:42 gears was only rated to tow around 5500#. Its all about the added HP and torque over the years, as well as a greater HP/Torque curve. In '95 the small block V8 in the full size trucks only had 200 HP and 310 ft·lbs. And it was all on the bottom end, 3500 RPM. Mine has 315 HP and 338 ft-lbs. Huge difference.

 

[Ghoster]

For 2008 there were only 2 gear options available for the Crew Cab, 3:73 and 4:10. With the 5.3, its 7500# for the 3:73 gears, and 8500# for the 4:10. I still need to look up the RPO codes to find out which gears I have, and if I have the MAX Trailering Pack. I bought it from a Ford dealer so they didn't know.


I can tell you that in the mid '90s, a Tahoe with 3:42 gears was only rated to tow around 5500#. Its all about the added HP and torque over the years, as well as a greater HP/Torque curve. In '95 the small block V8 in the full size trucks only had 200 HP and 310 ft·lbs. And it was all on the bottom end, 3500 RPM. Mine has 315 HP and 338 ft-lbs. Huge difference.

With the 2011 and up they also went to a 6 speed tranny. Mine has the 3.42's and the K5L HD cooling. its rated at 9500 or 9600 lbs. The trailering chart in the Silverado manual is like 3 or 4 pages long. Waaaayyyy too many options!

 

[Robbabob]

I've learned that's not quite accurate. I get the same with the TB as I got with our '95 Suburban, maybe 1/2 mpg better. But that's all. It was a big dispointement when we bought the TB 8 years ago. .

Point well received.

YOU CAN NEVER HAVE TOO MUCH HORSEPOWER AND TORQUE WHEN IT COMES TO TOWING.

That said, does anybody know the (approximate) towing capacity of the Tahoe/Yukon or the Suburban?

Then, it's all a matter of gears, grab them when you need them... Just remember, you still need to be able to stop that load!!!!

Enjoy

 

[DocBrown]

With the 2011 and up they also went to a 6 speed tranny. Mine has the 3.42's and the K5L HD cooling. its rated at 9500 or 9600 lbs. The trailering chart in the Silverado manual is like 3 or 4 pages long. Waaaayyyy too many options!

Yes, 6 speed! GM waited far too long to do that!

Just remember, you still need to be able to stop that load!!!!

Enjoy

That's what trailer brakes are for!

 

[Ghoster]

Yes, 6 speed! GM waited far too long to do that!

Agreed. I have had it in three trucks now and I love it. It does take a while to learn my driving style. Once its dialed in it is as smooth as silk.