For most drivers, climbing and descending hills or even mountains isn't really cause for concern. This is especially true if you drive a vehicle with an automatic transmission, since basically all of the work is done for you. You just keep the gear selector in drive, and depending on the incline and how hard you press the accelerator pedal, the transmission will downshift to find the proper gear to maintain the requested speed. Once you've crested the hilltop, you can keep both hands on the wheel as you coast down the other side. You may have to tap the brake occasionally on the downhill side -- just to keep your speed below the posted limit -- but other than that, an automatic transmission generally takes care of the rest.
A manual transmission is a little trickier, but only slightly. The driver can select any gear he or she chooses to climb or descend the hill. In fact, proper gear selection on the downward side of the slope can limit the speed of the vehicle, often enough to eliminate the need for the driver to touch the brakes. The obvious advantage is that this reduces wear to the vehicle's braking system. In the hands of a skilled driver, a manual transmission-equipped vehicle can make it up and over a mountain just as easily and smoothly as an automatic.
But what about shifting while towing? When you add the weight of a trailer behind a vehicle, finding the right gear might not be quite so simple anymore. How do you know what gear to select when you're towing a heavy load? How does a tow vehicle with an automatic transmission handle the extra weight of a trailer? And how much of a factor is the terrain in the proper gear selection? Read the next page to find out.
Tips for Shifting While Towing
When you're shifting while towing a trailer, proper gear selection is critical to reduce the amount of strain placed on the tow vehicle. This applies to manual transmission-equipped vehicles as well as those with an automatic transmission. Now, you may be thinking, "Proper gear selection in an automatic?" In recent years, some auto manufacturers have included a tow/haul mode on some cars and trucks equipped with an automatic transmission. The tow/haul mode reduces an automatic transmission's constant search to find the proper gear to suit the terrain. On vehicles equipped with an overdrive off feature, locking out the overdrive gear will have a similar effect [source: Job].
Manual transmission gear selection, as you would expect, is in the hands of the driver. One of the most important things to remember when you're shifting while towing with a manual transmission-equipped vehicle is to be conscious of the terrain. Being prepared to shift at just the right moment as you're climbing a hill can mean the difference between making it to the top nearly effortlessly and straining and coaxing your vehicle every inch of the way.
Gear selection when descending a hill while towing is equally important with a manual transmission-equipped vehicle. The added weight of a trailer can cause a vehicle to go down a hill a little (or a lot) faster than you might expect, and the extra weight may prove too much for the brakes to handle. What's the solution? How can you maintain control? The answer is the same as when you're not towing -- engine braking, or using the engine rather than the brakes to slow down. To do this, you simply remove your foot from the gas and downshift into a lower gear. The engine's RPMs go up, but the vehicle slows down as the engine acts as a compressor to reduce the speed. This reduces brake wear and keeps the vehicle limited to the speed that you feel comfortable with based on your gear selection.
To read more about shifting, towing and other related topics, follow the links on the next page. They can provide you with a lot more information.
Related HowStuffWorks Articles
More Great Links
- Job, Ann. "Towing Tutorial." MSN Autos. (Sept. 16, 2008) http://editorial.autos.msn.com/article.aspx?cp-documentid=434834
- RV Basics. "RV Fifth Wheel & Travel Trailer Towing Safety Tips." (Sept. 16, 2008) http://rvbasics.com/techtips/travel-trailer-towing-safety-tips.html