I have a 2004 Toyota Sienna without the trailer towing package. The manual lists the capacity as 2000lbs without the package and 3500lbs with the package. I called the dealership to determine what the difference is and they did not know. All the dealership (both parts and service departments) knows is that they can install a hitch and harness for $400. The hitch is class III which is 3500lbs, but they don't know how to tell if the vehicle has the towing package, or not. The service department thought that the towing package was simply that the vehicle was sold with the hitch installed already. He didn't understand the weight difference. Does anyone know where to find competent Toyota answers?

I could have written this myself! It is exactly what I want to know. Can somebody please help?

Thanks,
Jim

Having done more research and consulted with a dealer, my best information says that the towing package was standard on all 2004-2007 Siennas. They made it an option beginning with 2008. So all 2004-2007 have the heavy-duty cooling sytem, alternator, trans. cooler, etc. and are capable of towing up to 3500 lbs.

Somebody please correct me if I am wrong.

Thanks,
Jim

I am looking at BUYING a 2004 or 2005 Sienna to tow my pop up camper. I was told that for those years the XLE model came standard with the mechanics needed for towing (towing prep package -ie. extra trans cooling, ect) you have to take it to get the actual hitch installed after market. I was told the LE did NOT come standard with the towing prep package for the '04, '05. The research I've done also leads to the 3500# capacity WITH the trailer prep package.
Hope this helps. To be safe, I plan to have the dealer give me the specs for the SPECIFIC vehicle, before I actually BUY it...

The towing capacity is generally specified with two different weight limits that reflect the POWER of the vehicle and the BRAKING ability of the vehicle. The towing package itself is only really required if you are going to be towing a lot, if you are going to be towing on a lot of hills, or in some other situation where you think extra cooling may be required for both the engine and transmission.

You should also disable the over-drive on your vehicle when in town or changing speeds a lot under around 80km/hr (sorry... Canadian eh.) as this will generally reduce transmission overheating due to slippage (this is the reason most automatic transmissions have a button to disable over-drive).

I own a 2001 Sienna, but am experienced at towing with many vehicles and suspect if you looking at the fine print in the manual you will find the 2000lb tow rating if for a trailer that does NOT have it's own brakes. The 3500lb rating will be for a trailer that has it's own independent braking system and is therefore related to the maximum power/frame handling of the tow vehicle.

Braking systems for trailers can be electric (tied to the electrical system of the tow vehicle and activated with the decelleration and brake pedal action of the tow vehicle).
Alternatively some trailers have a hydraulic system built into the tonge of the trailer so when the trailer pushes on the car it actually forces the trailer brakes to turn on.

Please pay close attention to the total gross vehicle weight. It is easy to load up the van with passengers and luggage, this reduces the total safe capacity of the van to tow. You don't want to get in a situation where the total combined weight of the van, plus passengers, plus luggage, plus trailer ends up exceeding the total capacity of the vehicle.

Hope this helps.