Should I Use Tow Haul Mode On The Highway?

When It Makes Sense

• Good fit: You are towing a heavily laden trailer through mountainous terrain with long downhill sections. Engine braking provided by tow haul mode helps maintain a safe speed without overheating the service brakes.
• Good fit: You are pulling a high‑profile vehicle (e.g., a boat or RV) on a highway that includes steep grades and you need additional engine resistance to reduce reliance on trailer brakes, especially if the trailer lacks its own braking system.

When You Should Avoid It

• Warning sign: You are traveling on a flat, high‑speed interstate where the vehicle is lightly loaded. Engaging tow haul mode can reduce fuel efficiency and cause the engine to operate at higher RPMs than necessary.
• Warning sign: Your vehicle’s owner manual explicitly states that tow haul mode is intended for low‑speed, steep‑grade conditions only, or your vehicle does not have a dedicated tow haul system. Using it in an unsuitable situation may lead to premature transmission wear.

Pros and Cons

Pros

• Provides additional engine braking, allowing you to control speed on steep descents without over‑using the service brakes.
• Can reduce brake fade on long downhill runs, improving overall safety when towing heavy loads.

Cons

• Increases fuel consumption because the engine works harder at higher RPMs.
• May cause unnecessary wear on the transmission and drivetrain if used on level or mild‑grade roads.

Decision Checklist

• Is the road profile steep enough (grade > 5%) to warrant extra engine braking?
• Is your trailer equipped with its own braking system, or are you relying solely on the tow vehicle’s brakes?
• Does your vehicle’s manual endorse tow haul mode for the specific speed range and load you are carrying?

Alternatives to Consider

If tow haul mode is unsuitable, you can achieve similar control by downshifting to a lower gear, using the vehicle’s manual transmission (if equipped), or relying on a trailer with integrated electric or hydraulic brakes. Additionally, planning routes that avoid prolonged steep descents can minimize the need for extra engine braking.

Final Recommendation

Use tow haul mode on the highway only when you are towing a substantial load through sustained steep grades where engine braking adds safety and preserves service‑brake life. On flat or mild‑grade highways, or when the trailer has its own brakes, keep the mode disengaged to conserve fuel and protect the drivetrain. Always verify the vehicle’s owner manual for manufacturer‑approved usage, and consult a qualified technician or towing specialist if you are uncertain about the appropriate setting for your specific situation.