Trailering a 22' boat

[Capt E]

I have a stock 08' Tahoe with the 5.3. I usually tow an 18' boat and never had any issues. I am getting a larger boat which I had to tow on the interstate the other day, and the truck was struggling a little bit. The 22' boat weight is just over 2000 lbs. In town speeds it was fine but at interstate speed, 70 mph, it just didn't want to stay in overdrive.

I tried to keep the speed at 70 but had to consistently accelerate to keep it there. When doing that the truck was running at 3000 rpm's just sucking down the fuel. I'm in south Florida so there wasn't any real inclines besides overpasses and bridges.

My question is, does the above seem normal? What can I do to fix the issue? Wasn't sure if a programmer would help by giving 10-20 hp extra. Really don't want to do exhaust due to the noise. Any suggestions would be great.

 

[Regency]

You had it in tow/haul mode right?

 

[jdpber]

DO NOT get a programmer.. get a Black Bear Tune..

I have towed a number of different size and shape boats over the years...

FIRST - what style is the boat? a 22' flats boat is going to tow a lot easier than a 22 cabin or T top bc of wind resistance and drag..

you are probably dealing with more drag than the 18 and this is your main issue

 

[Capt E]

I tried with tow/haul on and off, made no difference at that speed.

The boat is an Aquasport 22.2 center console. V hull in front and 8 degree deadrise transom, so I'm sure there is some drag there. The trailer was a dual axle w/ brakes, the trailer was functioning fine.

 

[domin8]

I agree with what was just said.

Get a real tune and not a programmer.

Wind resistance may be playing a factor.

With that said, at the end of June I made a crossing over the Appalachians while towing a 3400 lb car on a 2000 dual able trailer with hydraulic brakes (via Uhaul). Estimated weight was ~ 11600 lbs. The only times I really saw the truck go into OD was when I was going downhill. Even on flat surfaces it was normal to be in 3rd. As for uphill, well let's say I'm sure glad I installed the GM auxiliary trans cooler and changed the radiator to one from a police Tahoe so that I could install the engine oil cooler lines. Trans temps on some inclines got around 210°. Oil pressure remained fine and water temps remained normal. I never let off the gas on those hills (because I let cruise control handle the whole trip). Yeah, fuel economy may suck at 3000rpms, but imagine what it's like when the truck sits near redline on some good long inclines. She took it all and kept asking for more, while averaging 9mpg all the way from Norfolk, VA to Chicago, IL. Oh, did I mention I had a carrier bag strapped down on the roof too?

Imo, these trucks are tough and 2000 lbs is nothing for them. If you're really concerned, I'd add the GM auxiliary trans cooler and the engine oil cooler lines and heavy duty radiator, then add a tune. Keeping things cooler should help with fuel economy slightly. Also consider a CAI to go with that tune. Last year for the GM one was 2008. And, while you're in that GM Accessories catalog, look into the Touring Catback Exhaust. It's suppose to add a little more power and still be quiet.

 

[felixgun]

Get a cold air intake like Airaid or K&N and then get it tuned accordingly with a BB Tune. Transmission shifting points will change (which I think would help) after the tune and CAI/tune combo will make the truck come alive!

 

[Capt E]

Thanks for the replies. I'll see what I can get changed.

 

[TowGMC]

I tried with tow/haul on and off, made no difference at that speed.

The boat is an Aquasport 22.2 center console. V hull in front and 8 degree deadrise transom, so I'm sure there is some drag there. The trailer was a dual axle w/ brakes, the trailer was functioning fine.

You're towing a whole lot more than 2,000 lbs. That hull alone is just over 2,000, add in another 500-600 for an outboard, and another 1500-1800 for a dual axle trailer with brakes and you're somewhere between 4,000 & 4,400 lbs. Assuming no fuel in the boat's tanks etc.

My Denali pulls 4,000 with little effort when I leave it in 5th gear (Blackbear tune lets me hold gears without downshift in Manual+Tow mode, pretty slick!), but when I hook up my 6500lb enclosed trailer it will only pull in 5th on flat ground, and needs 4th to pull any hills. And that's with my 6.2. I seriously doubt I could pull this trailer with a 5.3 Tahoe without leaving it in 4th all the time, and let it go to 5th on downhills.