Hello, I have a 2004 toyota tundra 4x4 with the standard tow package. I am looking at buying camping trailor. Have towed a 19 foot camper without di fficulty. Want to know what the largest camper I can saftely tow and what I could do to increase the amount I can tow with it.
You've asked some mighty open ended questions and it doesn't look we've got anyone who'll take them on...so I'll offer you enough to get started. After you read what I outline below, your next step is to start searching through all the posts on this forum until you get knowledgeable enough to ask specific questions....those will almost always get you good, and specific advice.
When the word "largest" comes up, you first have to realize that there are no less than
four key measurements you have to constantly evaluate as you're considering a trailer.
The first is total weight...not just of the trailer but of the combined trailer and truck. If you're smart, you'll always keep this well below the Gross Combined Weight Rating (GCWR) of your truck....which is a not overly impressive 11,800 lbs. So, to figure how heavy a trailer you can pull, you subtract the weight of the loaded truck from the GCWR. The smart approach to this is to assume you'll probably load the truck close to its max weight...the GVWR...on a trip. You certainly should never use the truck's published curb weight...it will be at least a 1000 lbs too low. Given you have 4x4, a fairly good loaded truck number would be 5800 lbs (6100 lbs if you have the Double Cab).
Which means the heaviest trailer you should be considering is about 5800~6000 lbs when loaded . BTW, totally forget the rated "tow capacity" because that number was derived by subtracting the weight of a totally empty, totally bare bones truck from the GCWR....in other words it's a useless, bogus number in the real world.
So you're now limited to a trailer that's under
6000 lbs loaded That means the number you should compare against when shopping for a trailer is its GVWR, not it's published "empty" or base weights. Like your truck's tow capacity, the empty weights of all travel trailers/campers are totally unrealistic because they don't include factory or dealer options and they don't include the hundreds (maybe thousands) of pounds you'll be loading. The reality is that most people will quite rapidly load their trailers right up to the trailer's gross weight rating. So
use the trailer's GVWR number when you're doing your calculations.
The 2nd big measurement is the trailer's total length....the longer it is, the harder it will be to control when it starts to sway. The standard rule for many years has been that you should have 4 inches of tow vehicle wheelbase (over a base of 112 inches) for each foot of trailer length over a base of 20 feet. That rule computes out to indicate an Access Cab Tundra shouldn't tow a trailer longer than 24.5 feet and a Double Cab shouldn't tow anything longer than 27 feet. And that's with mid-quality weight distributing hitch and basic (friction) sway control. People are certainly towing trailers that are longer than these guidelines but they're taking a real risk of uncontrollable sway if they don't also use high end sway control....like a Reese high performance dual cam or a Hensley Arrow.
The next big measurement is tongue weight....for two reasons. First, the hitch receiver on your truck is limited to a max tongue weight of around 1100 lbs (with a WDH) and around 750 lbs (no WDH). Exceed that and you can break things. Second, the weight being put on the hitch from the trailer's tongue counts against your truck's total weight....so if your truck is weighing 6000 lbs by itself (and has a 6600 lb GVWR)...and you add in an 800 lb tongue weight, you've just overloaded the truck because you've exceeded the GVWR.
And finally, you have to be very careful to not exceed the Gross Axle Weight Rating of the rear axle. On your Tundra, that's a fairly small 3760 lbs. If you have a 500 ~ 800 lb load in the bed and attach a trailer with an 800 tongue weight without using a WDH, I guarantee you'll exceed the GAWR (rear). And that, if done over enough miles, leads to destruction of the rear axle bearings and, sometimes, to cracked frames and cracked axles.
So there you go...you've got to be sure you don't exceed the GCWR, the GVWR, and the GAWR (rear). If you buy a trailer with GVWR of 5500 lbs or less...and use a good WDH, you'll probably be OK on all the weights. But if you get carried away and buy a trailer with an empty weight over about 5500 lbs, you'll very likely have a big problem. Similarly if you buy a too long trailer...one that's more than about 26 feet (AC) or 29 feet (DC), you'll have one heckuva problem with sway control.
As for increasing the "amount" you can tow, there are no mods whatsoever that will allow you to safely exceed the GVWR, GCWR, or the GAWR. There are some mods that will make towing at near these max weights more enjoyable...adding headers to the engine being one that safely will give you better towing performance. And you can increase the suspension spring rate to better handle an allowed load...but
never, ever get it into your mind that "beefing up the suspension" will allow you to safely exceed the GAWR, GVWR, or GCWR. And, in any case, the springs you usually need to beef up to handle trailer induced rear sag are
not the ones between the truck and its axle but rather the ones that are part of the WDH.
The one place you can do something to increase the size of trailer you can safely tow is to use a very high end hitch...for instance, as long as the truck's various weight ratings are not exceeded, you could probably safely tow a lightweight 36 foot trailer (e.g. an Airstream) with a DC Tundra as long as you used a Hensley Arrow hitch. But be aware that a Hensley Arrow retails for around $3000...
that's 3 Grand just for the hitch.
This oughta get you started...now go forth and study the previous threads on this forum.