The 2008 Toyota Highlander is a popular SUV and most people use them for toting around the family and that's about it, but they would probably be surprised to find out that they have a decent towing capacity as well.
This article goes into depth about how much weight these vehicles can actually pull and what equipment you need installed on your vehicle to be able to pull the maximum weight possible listed in the charts. I took screenshots of charts I found online and other tow related resources I found online, organized it and posted it here!
Be sure you read through your owner's manual to see what Toyota recommends when it comes to towing and anything else related to your vehicle.
2008 Highlander Overview
Overall Towing Capacity:
The towing capacity for the 2008 Toyota Highlanders ranged from 2,000-5,000 lbs. and really just came down to whether you had a towing prep package installed on your vehicle. The Hybrid models only had one specified rating and not really a range, and that was set at a maximum of 3,500 lbs.
Engine Options: There was only one engine option available for these SUVs and that was a 3.5 L (six cylinder) engine, but since there were Hybrid models available, there was another engine choice for these vehicles and that was a 3.3 L (six-cylinder) engine.
Assumed Weight: I was not able to find a definitive answer anywhere in the owner's manuals or the brochure it talks about any assumed wait in the vehicle, like a driver, that I typically see for other vehicles when specifying the maximum trailer weight rating. Typically, 150 lbs. is the average "assumed weight" of a vehicle since you need a driver to control the vehicle.
Standard and Hybrid Charts:
There are two separate charts listed for the 2008 Highlanders and this is because they had the standard models which used a gasoline engine and they also had a hybrid model that had a different maximum weight rating.
Below I have listed the standard chart first for models that used the 3.5 L gasoline engines and as you can see, you either had a 2,000 lb. or 5,000 lb. rating, depending on if you had a towing prep package equipped on your vehicle. Below that chart is the hybrid chart, and the maximum capacity was set at 3,500 lbs. for those models.
 Before towing, confirm your vehicle and trailer are compatible, hooked up and loaded properly and that you have any necessary additional equipment. Do not exceed any Weight Ratings and follow all instructions in your Owner's Manual. The maximum you can tow depends on the total weight of any cargo, occupants and available equipment.
 Requires available Towing Prep Package.
Tongue Weight Rating:
I was also able to find the maximum tongue weight rating for these vehicles, which ranged between 9 to 11% of the total weight of the trailer. The maximum tongue weight limits were set at 200 pounds for vehicles that did not have a tow prep package equipped and 500 pounds for vehicles that did have one of these packages equipped.
If your overall trailer weight and cargo was less than the maximum trailer weight rating listed in the chart above, then you would try to shoot for around a 10% weight on the tongue in order to meet this criteria. For example, if your trailer and cargo only weighed 1,200 lbs., then you would want roughly 120 lbs. on the tongue (or hitch) of the vehicle.
Like most vehicle manufacturers out there nowadays, there was a requirement for having trailer brakes equipped on your trailer, independent of your vehicle's brakes, if your trailer weighed more than 1,000 pounds. This is also true for the 2008 Highlanders and accounts for the lower end of the spectrum when it comes to the maximum trailer weight range.
GVWR, GCWR and GAWR Figures:
GVWR: The gross vehicle weight rating was listed in the charts that I have posted at the top of this article, which makes it really nice to view those statistics as well.
If we look at the charts, we can see that the gross vehicle weight rating ranged from 5,800-6,000 lbs. for models equipped with the 3.5 L gasoline engine, but I was not able to find any specifics on the hybrid models In the owner's manuals, so you'll probably have to look it up on your certification label instead.
GCWR: I was not able to find the gross combined weight ratings anywhere in the owner's manuals or in the 2008 brochure, but you can get this figure by adding the gross vehicle weight rating and maximum trailer weight rating together and it should be close enough, for the most part.
GAWR: The gross axle weight rating was also not posted anywhere but I know for a fact you can find this on the certification label on your vehicle, which I will talk more about where you can find this label below.
Certification Label: All Vehicles have a certification label that is also known as the safety certification label and it is required by law for vehicle manufacturers to have these somewhere on their vehicle. For the 2008 Highlanders, it is located on the driver side door pillar, which you can see in the image below.
This will usually have the gross vehicle weight rating, gross axle weight ratings and other helpful information like the VIN, tire sizes and pressures and other helpful bits of information that you might need down the road.
The Tow Prep Package & What's Included...
I was able to find what was included in the towing prep package for the 2008 models and posted a screenshot of what I found in the brochure. We can see that a heavy-duty radiator that has an engine cooler port is part of the package, along with a 200 watt fan coupling, a transmission oil cooler and an upgraded 150 amp alternator.
Usually these types of packages will include the hitch receiver and a wiring connector for your trailer, but I did not see this listed, so I'm not sure if it was included in the package or if it was just not mentioned. If I had to guess, I would assume that they would include these items as part of the package.
Other Notes I Found:
Reading through the owner's manual, I was able to find other little tidbits of information that I think would be of interest to most people and took screenshots of what I found below. These are very important bits of information and is why I recommend you read your owner's manual to get familiar with everything that Toyota recommends.
All of my research for this article was taken from the owner's manuals for both the hybrid and gasoline powered models, along with the brochure, that proved to be helpful as well. I wanted to link to these resources below for those of you out there that want a quick way to see where I got my information and if you want to do your own research, it just makes it that much easier!