Can I really tow that much?

[Perry]

I'm about to purchase our first travel trailer, and have been lurking in the RV forums. Whats interesting is that over there, people flame folks that are towing trailers right at the limit of their vehicle ratings. Its always people with 1/2ton trucks or Ford Expeditions towing 7000#+.

Over here it seems most trailers are way over the weight Chevy publishes that you can tow with our 6.5's. I know your rigs are also modified to handle it and you all keep an eye on temps and such.

So how much can I really tow? When i ordered my rig, the Chev brochure said 7500# w/my 3.73 rear, but when I finally got the Suburban and read the diesel manual supplement, it stated 6000#s.

I've been towing my enclosed car hauler (about 6500# loaded), but only local. With the travel trailer, I will have to cross at least two mountain passes and the Arctic Fox trailer I'm looking at has a 7875# loaded GVWR rating, 5500# dry.

My Sub is stock but I just ordered gauges (EGT, Boost, Trans) and a new Heath exhaust. I would consider more modifications, but I still have 2 years left on my extended warranty.

Can I get this trailer or do I need something lighter? Can I make it over the passes with the setup? And what do you do when the EGT starts to climb - just slow down? How slow is slow?

Thanks for any info.

Perry

[More Power]

Hi Perry,

You might want to begin with the following link to learn more about tanker's 6.5TD Suburban and his experience with towing a TT.

http://www.thedieselpage.com/members/features/mccauley.htm

MP

[marktara]

I'm interseted also in what other members tow and how well your trucks handle it. I bought a 25 foot fifth wheel with a GVW of 8000 pounds and am now wondering how my truck will handle it.Seriously thought about buying a Dmax, but didn't like the idea of making payments and besides I thought if I bought a intercooler along with the mods already on my truck it should pull my trailer as good as a Dmax. I guess time will tell.

[jjackson]

Perry, before I got my '03 Dmax and new 33' 5th wheel that is right at 13K loaded, I was pulling a 30' Sierra Travel Trailer by Forest River that weighed 8500 loaded, with my 1989 Chevy Conversion Van w/a 350 and 3:73 gears. I modified the suspension, had air shocks, an engine oil cooler and two transmission coolers. I traveled from Tampa to Seattle, then East through the Dekota's and then south heading back home. Went 11,300 miles and didn't have one problem.

John

[rjschoolcraft]

The trailer you're looking at weighs less than mine does. I towed mine for three years with my Suburban before modifications. Went to Yellowstone and several other places. Your vehicle is a 99, so it will have many of the improvements that I had to add to mine. With the gages, you should be able to go anywhere you want to.

[Perry]

Ron, what kind of mileage were you getting while towing, prior to the modification? did it change after the mods?

Perry

[MikeC]

Perry,

My rig, loaded to go camping for 1-2 weeks, weighs in at 9500#. This includes all food, clothes and full propane tanks. It does not include water, waste or fresh.

I have modded the truck and most mods can be seen in the readers rigs section - Mike Cooper's Suburban.

Some mods have changed since I wrote the article. If you want more specific info feel free to email me at mcooper at uaoh dot net

Good Luck!

Mike

oops, almost forgot. the rig weighs 17500# total with the Burban full of fuel and the back packed with firewood, oil, filters etc etc etc. mc

[Turbine Doc]

Perry,
These trucks are significantly more capable than GM rates them at if properly equipped and the driver in the seat is smart in how they operate their vehicle. Remember GM has to limit what they will allow for based on Joe average driver, liability being what it is these days no way will they open themselves to saying to tow more than their design limit.

With my 1/2T I can and have towed up to 18,700 GVRW, I don't do it regular or for long distance, but I'm also highly modded. As for your warranty, even the exhaust mod can cause you heartburn, mine tried to deny a claim because of the Banks gauges and exhaust, I fought an uphill battle but finally won out, as they have to prove mods cause a failure.

Read fine print some say they can deny a claim for any modification, it can be fought but be forewarned it ain't easy. I'm even with my warranty co covered parts vs for what I paid for the warranty, probably never get another claim out of them now.

As for improving capability of the truck, exhaust is a good place to start, so are gauges, slotted/drilled brake disks, Hi perf pads/shoes are also good upgrades as GMs brakes can be a weak link when towing.

[rjschoolcraft]

I averaged about 8 mpg before mods. I now average about 7.5 mpg. :( However, I do run faster now! :D

Check out the thread that I started "Significant improvement in towing performance! (http://forum.thedieselpage.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=1;t=005059)" to get an idea of the performance changes.

I really believe that I've only begun to scratch the surface here.

[Perry]

Ron, on the other thread you mentioned, just wanted to confirm the only mods you made before this trip compared to previous was the IC, fan, and fan clutch?

And you were experiencing the overheating problems and slow hill climbs last year, even with the JK Chip, dual t-stats, HO H2OPump, and exhaust?

So what was it like towing before any mods were made? If you were having problems last year with your first set of mods, how could you get over the mountains w/the stock setup before?

I thought I was only going to do the exhaust upgrade (getting installed tomorrow) and gauges to keep the warranty police happy. But then yesterday after reading all the other posts here about towing and talking with Bill Heath about all the mountain passes in our area, I decided to get his ECM reflash, PMD isolator and fan drive upgrade. I guess I'll just swap the ECM when taking the truck for dealer service and argue with them on the PMD setup if necessary.

But even with these mods, you have me worried again. This Aug, we'll be going on a loop from Seattle to Chicago and back. Outside temps will be over 100 and there will be lots of hills to deal with. Based on your experiences, the IC sounds necessary or my mods are for naught when towing. Tom's Sub on the member pages also has an I/C. Besides being big $$$, the IC would be harder to hide or justify if warranty issues came up.

Have I done enough to make our summer trip uneventful? Or will I need to only drive a night?

Perry

[rjschoolcraft]

Your 99 may not have the same overheating problems that I had.

I ran into a set of compounding problems...

1) I was towing heavy
2) I don't like to slow down...
3) Temperatures were high in southern California
4) High intake air temperatures were causing the computer to pull back on boost, which increases EGT, which increases coolant temp, which also causes a pull back in boost and fuel... See the cycle.

What I finally did was learn some patience. I wanted the chip and HO cooling mods to fix my problem completely. They did help, but were only part of the solution in the long run. I had some problems in stock form, but learned to just slow down and manage the issue and we made it to all the places we wanted to go.

Your stock programming is really pretty good. Adding a Kennedy boost controller would bring the boost up, which helps power and lowers EGT. The boost controller is about $90 IIRC.

Your trailer will weigh between 600 and 1200 lbs. less than mine. How many people and how much gear will you pack into the Suburban? I have four children ranging in age from 17 down to 8. we run the Suburban at or above GVWR of 8600 lbs. while towing. If you will not be hauling that much, you may take another 1000 lbs. off the combined weight. That all makes life better.

I have towed far more miles with the Suburban in stock trim than with the modifications. I made it everywhere after learning some patience, but it is much more enjoyable now. Hope I don't scare you too badly. I would like to have your Suburban, since it is four years newer than mine.

If you do end up needing to change out your fan clutch, I would install the 98 water pump and use Kennedy's clutch, since it is the only one engineered to be a real improvement over stock with a recalibrated engagement curve. Unfortunately, it is not available in the 99 screw on style.

[arveetek]

Perry,

I tow a 29' fifth-wheel that weighs around 8500 lbs with my '81 6.2L n/a diesel. I've pulled my rig from Missouri to South Carolina, down to Florida and back, to Ohio, and several other places with no problems at all, other than a little lack of power. You won't have a bit of a problem with your rig, especially with the upgrades you have in mind.

If EGT's get too high, just let up off the throttle a little bit. You'll slow down some, but not much.

Casey

[JoeyD]

Perry, I see your adding some more power with the ECM, but have you thought about intercooler? From reading here this is where mods should start. With your stock ECM intake air temp will climb and fuel will be cut back. With the new ECM flowing more fuel intake temps will climb faster.