Advantage of Manual Transmission in Off-Roading

Manual transmission cars are a dying breed. Automatic transmission is starting to match the performance and economy of manual transmission. If you look at acceleration numbers, auto many times still lag manual transmission time. Torque converter does suck away power. More new car buyers are selecting manual transmission over automatic. However, it is curious that in the used car market, manual transmission do typicall command a higher price especially in specialty cars. One example is the 2018 Porsche GT3. Manual transmission came back to the GT3 after Porsche realize in the used car market the last second hand manual transmission GT3 Porsche was commanding over a million just because it has a manual transmission. People have recognized that manual transmission is still desirable in some circumstance.

Question is for off-roading, which is better manual transmission or automatic transmission? I will discuss an advantage of manual transmission that is often not talked about.

 

Terrain Feel

Automatic transmission uses a torque converter to slip the drive when starting, changing gear or anytime torque converter is not locked up. With the manual transmission, there is a one to one connection between engine and wheel. By listening to the engine, you know how fast the vehicle should be going. If the engine accelerates, and the vehicle does not accelerate, you know the tires are slipping.


Automatic on the other hand slips the torque converter. When the engine accelerates, is impossible to tell whether it is the torque converter that is slipping or the tires that is slipping. As a result, with automatic transmission, is difficult to feel for traction.
With a manual transmission, you have constant feedback on the terrain. When you have more seat time in the car, you know the power the engine puts out with relationship to gas pedal. By stepping on the gas pedal, and seeing how fast the vehicle accelerates, you can tell get a feel for how much traction margin you have. For example if you are going smoothly on a muddy trail, and the moment you depress the gas slightly more, you hear the engine rev a little, but not a corresponding acceleration, you know you are at the edge of losing traction. That actually have saved me once on a dry lakebed as the trail got muddier.


Manual transmission also has a better feel for starting traction. After more experience in the car, you can tell exactly how much power you are putting into the tires by the let up of the clutch and the position of the gas pedal. You know how exactly how much the vehicle should be accelerating. If there is a discrepancy, you know the tires are slipping.


With manual transmission, the vehicle feels like an extension to your foot. You can sense exactly how much traction you have, and where the slippery spots are on the trail. With an automatic transmission, is much more difficult if not impossible to feel for traction.

Starting on Hill

Starting a manual transmission on a hill traditionally has been the most difficult part of driving a clutch car. It does not have to be that way. The traditional way for starting on a hill is either to use the handbrake or to let the clutch out halfway then quickly transfer the foot from brake to gas. Neither of those techniques are satisfactory for off-road driving. The solution: Heel-Toe Shifting.

Traditional race car drivers use Heel-Toe shifting when downshifting and rev matching the engine for the corner. That technique is a perfect adaption for off-road driving. We are not using it for downshifting, but rather starting on a hill. The basic of the Heel-Toe is the toe (or ball) of the right foot steps on the brake while the heel of the foot steps on the gas. If done correctly, the right foot will be stepping on both the brake and the gas pedal, and have perfect control on both pedals. That leaves the left foot for the clutch. It will seem completely foreign, and difficult to learn at first, but the trick is to practice it on your daily drive. If you are going thru stop and go traffic or thru stop signs, you will be practicing Heel-Toe during every slow down. You will be surprised in less than a month, you will be quite comfortable with it. After a year, you will be really good at it.

How effective is Heel-Toe for off-roading? Very effective! My 4Runner has open differential on both ends. One time in a group run, the rear tire made it up a vertical rock and the engine stalled with the tire half way off the edge of the rock ready to fall off with a big bang when the chassis hit the rock. The bystander had a nervous look on his face as he shouted watch out, your tire is already half way off the rock! Use the starter to get going. No problem, Heel-Toe step with a firm pressure on the brake while pressing the gas at the same time. As the engine build up rpm, slowly let out the clutch while releasing pressure on the brake. I did not over rev the engine, and the truck did not even roll backward an inch. It was just a smooth start with just enough engine rev to get the truck going. I don't like using the starter to get going. Do not want to risk burning out the starter or prematurely wearing out the starter in the middle of no where.

 

 

 

 

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