Manual vs. automatic transmissions: Which tows better?

Dear Car Talk

Dear Car Talk | Mar 01, 1991

Dear Tom and Ray:

In a vehicle used to tow a travel trailer, if both were operated and maintained properly, which type of transmission would likely require the least repair; an automatic or manual? I plan to keep the tow vehicle approximately 200,000 miles.

RAY: Well, Fred, if you're planning to tow a travel trailer 200,000 miles with a manual transmission, make sure you also sign up for the "Clutch of the Month Club."

TOM: The thing about clutches, Fred, is that if the clutch pedal is all the way up or all the way down, nothing really wears out. The damage is done when the pedal is somewhere in between. So when you're starting from a dead stop, and letting out the clutch, those few seconds when the clutch is engaging are when 95 percent of the clutch wear takes place. That's when pieces of the clutch are rubbing together in an ancient and destructive clutch ritual we call "slipping."

RAY: The clutch HAS to slip in order to ease the car into motion without bucking and stalling. But the more weight you have in tow, the more slippage you need just to get off to a smooth start.

TOM: So an automatic transmission is what you want, Fred. Automatics use a fluid coupling instead of a dry, mechanic clutch. The fluid coupling is designed so automatics can slip almost to their hearts' content without doing any damage. That makes them the best choice for situations that call for lots of slippage, like towing a trailer or frequent stop and go driving.

RAY: And by the way, Fred, you should definitely get an optional "trailer towing package." That usually includes a heavy duty transmission cooler, a more powerful battery and alternator, a set of rosary beads, and a complete gardening catalogue so you can quickly order replacements for all the flower beds you run over trying to back up this behemoth. Good luck, and send postcards.

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