What's the Best Transmission Cooler for my 2021 Toyota Highlander
Updated 11/13/2025 | Published 10/22/2025
Products Featured in This Question
Question:
2021 xle 2wd highlander with 8 speed transmission which is sluggish compared to my 2016 highlander which I traded in for this used 2021 and added K and N air filter along with going to replace plugs with iridium spark plugs and I tow a jet ski on occasion and is the 8000 series a good choice? What model would be easiest installation and perform decently please, and some friends are stating Hayden, but I feel your product will be better suited in the interim. Also will I need a additional hose to cover the complete unit and do you sell it ? thank you!
asked by: Rod T
Expert Reply:
Thanks for your question, Rod!
You picked out a great cooler! The Derale part # D13501 would be an excellent choice for your Highlander. The 8000 series cooler uses a plate-and-fin design, which is one of the most efficient styles available for your vehicle.
Placement also plays a big role in how well the cooler performs. The diagram below shows the ideal mounting locations:
Position A – The cooler operates at 100% efficiency.
Position B – The cooler operates at about 75% efficiency.
Position C – The cooler operates at about 60% efficiency.
As a general rule, the farther back the cooler is mounted, the larger it needs to be to make up for reduced airflow. If you have enough space to install it properly, I’d say go for it!
For extra hose, we offer part # D13003 (4 feet long). For longer runs, part # D13007 provides 25 feet of hose.
(click to enlarge)
Product Page this Question was Asked From
Derale Series 8000 Plate-Fin Transmission Cooler Kit w/Barb Inlets - Class II - Efficient
- Transmission Coolers
- Plate-Fin Cooler
- Small SUV
- Standard Mount
- 11W x 5-3/4T x 7/8D Inch
- With 11/32 Inch Hose Barb Inlets
- Derale
more information >
Featured Help Information
Instructions
Continue Researching
- Q&A: How Much of a Rise do I Need for My 2025 Honda Odyssey for Towing a U-Haul Trailer?
- Article: Brake Controller 7- and 4-Way Installation Kit (ETBC7)
- Q&A: 2023 Forest Rive R-Pod 192 Storage Cover Recommendation
- Q&A: What do the Class Ratings Mean on the Transmission Cooler Pages
- Q&A: Availability of Axle Flip Kit for NuCamp T@B 320 Teardrop Camper
- Q&A: Best Transmission Cooler for a 2021 Toyota 4Runner
- Q&A: Transmission Cooler Recommendation and Installation Instructions for a 2007 Jeep JK 3.8 Liter
- Q&A: Do I Need a Transmission Cooler for Towing with a 2011 Honda Pilot with FWD
- Article: Frequently Asked Questions About Transmission Coolers
- Article: How to Winterize & De-Winterize Your RV (Simple Guide)
- Article: 2 Steps for Finding the Right Weight Distribution Hitch Size
- Article: Choosing the Right Suspension Kit for Your Truck and Trailer
- Article: Transmission Cooler
- Article: 5 Tips to Confidently Choose Your Weight Distribution Hitch
Gwendolyn Y.
11/13/2025
Hey Rod, how did the Derale 8000 series cooler work out on your Highlander? Did the placement you chose give you the performance boost you were hoping for when towing your jet ski? Your update could make it easier for others setting up a similar cooler.