What Does "L" Mean On A Car's Gear Shift? - Vehicle Freak

• Luka Kusic

Updated on March 24, 2022

Driving a car with an automatic transmission has several benefits over the manual gearbox, mainly in terms of convenience. Stick shift does allow the driver to change gears when they see fit, but modern automatics have more gears and provide a smoother and even more fuel-efficient ride.

Most automatic owners know how to operate the gear lever – Park, Reverse, Neutral and Drive. However, “3”, “2” and “L” positions are almost never used, to the extent that drivers forget what they’re for.

The “L” on gear shift stands for Low, a low gear mode that prevents the transmission from shifting up beyond the first or second gear. Not to be confused with low range, “L” gear mode has several useful applications. In this guide, we’ll explore how low gear mode works and what it can be used for.

Understanding Engine Braking

To better understand the purpose of the low gear mode, we need to learn what engine braking is.

When you’re driving downhill, if you set your car into neutral, it will act as a sleigh and accelerate uncontrollably. You can counter this by applying brakes, but they can quickly overheat and lose all braking power. You should never drive downhill while in neutral!

Engine braking occurs when you release the throttle, but the vehicle continues to accelerate. As the throttle valve is closed almost completely, a strong vacuum is created that saps a lot of the potential energy and creates the engine-braking effect.

In other words, when you press the gas pedal, the engine raises RPM and this rotational speed is transferred to the gearbox, and onto the wheels. When you’re driving downhill, the wheels want to spin faster than the engine, which is prevented by engine braking. By placing a manual gear level in 2nd gear, most cars will maintain a descending speed of 30mph, with no input on the brake pedal.

What happens when the “D” or drive mode is selected depends on the technology inside the vehicle. Modern cars have intelligent systems that know when the vehicle is going downhill and engage hill descent to assist to help the driver retain control. Older automatic transmission will continue to upshift as you continue to accelerate, which means the engine will never get to help you with braking.

To force an automatic to brake with the engine, you need to drive in a lower gear and prevent the transmission from shifting up while you’re descending. This is done by using the gear lever settings below Drive – “3”, “2”, and “L”.

Is Engine Braking Safe?

One of the most dangerous misconceptions in the automotive world is thinking that engine braking will damage the engine. Engine braking will not cause any damage to the engine, and even if it did, it’s far better to harm the engine, than to burn out brakes your brakes and accelerate uncontrollably.

But I’ll say it one more time to clarify: engine braking will not harm your engine. Your primary way of controlling the car on a descent should be through engine braking, with brakes applied before sharp corners. I cannot tell you how many times I’ve driven downhill and smelt burning brakes coming from other cars, while I hadn’t touched my brake pedal at all.

It may be scary the first time you try engine braking, as the engine will rev up high and make a lot of noise. This is completely normal and nothing to worry about – the engine is consuming a very low amount of fuel, and despite the high RPM, it’s actually preventing the vehicle from accelerating.

What Does “L” Gear Mode Do?

Almost every automatic transmission has the “L” gear mode, with some including either “3” or “2”, or even both. The “3” setting will prevent the transmission from shifting beyond the third gear, with “2” restricting it to only the first and second gear.

These are your standard hill descent modes, and you should use one or the other whenever you’re going downhill. If you’re driving a low-power automatic, keeping your car in “3” will also prevent it from shifting up when going uphill, which will keep the RPM high and provide maximum power for a safe ascent.

The “L” mode limits the number of gears you can use even further – only the first, and in some transmissions, the second gear will remain active. This will make the vehicle necessarily slow, with “3” being more than enough to keep the vehicle in control.

However, when you’re hauling or towing heavy loads, “L” can be a lifesaver. The added weight of the cargo not only speeds up the vehicle but also makes it much harder to decelerate when driving downhill. By setting the gear in “L”, the speed of the vehicle will be limited through engine braking, resulting in a safe descent.

When Should I Use “L” Gear Mode?

Whenever you’re facing an incredibly steep incline or descent, lower gears will provide better control over the vehicle while retaining low speed.

If a steep incline on a dirt road is ahead of you, stepping on the gas while in “D” will make you accelerate beyond the point considered safe on such a surface. Place the transmission in “L”, raise the RPM to an optimal level, and you’ll reach the top more easily.

It is crucial that you use the “L” gear mode when descending with a heavy load, like a camping trailer or towed car. If you’ve ever seen 18-wheelers crawl painfully slow down the hill, it’s because they’re doing the same thing.

That being said, “L” is still reserved for the most extreme scenarios. The first position below “D”, whether it’s “3” or “2” will be sufficient for most situations.

PRNDL Meaning

I’ve been asked this question several times in this exact manner (and not all of them were the Zack and Cody joke), so it felt appropriate to include a section dedicated to this question. While most people understand what each position does, many are not certain what each of the letters stands for.

“P” = Park, the position designed for parking the vehicle, as it engages the first or reverse gear and prevents the vehicle from moving.

“R” = Reverse, the gear for driving in reverse with limited speed.

“N” = Neutral, the position where transmission isn’t engaged and the vehicle can be pushed freely.

“D” = Drive, the position responsible for all forward-driving gears.

“L” = Low, the low gear setting that prevents the transmission from automatically shifting up beyond the second or the third gear.

FAQs

When should you drive in low gear?

As mentioned before, the “L” or low gear is a great way to control the vehicle when driving on hill roads. Modern cars do not have the “3” or “2”, making the low gear the universal option, with hill descent control designed to assist when hauling heavy loads.

Can you shift from D to L while driving?

The switch between drive and low gear can be done on the fly, but a good practice is to lower your speed before engaging in the low gear mode. Your transmission likely has a safety system that will prevent it from downshifting when the vehicle is moving too quickly, which also means that low gears won’t be engaged immediately. Learn how your vehicle drives and shifts, lower your speed and then engage the “L” gear mode.

Is it bad to drive on L?

Driving in low gear isn’t necessarily bad, but limits your ability to reach higher speeds, and driving any faster than those gears can take will increase your fuel consumption. The best practice is to keep the transmission in “D” and utilize “L” when necessary.

Summary

Now that you’re familiarised with the meaning of the “L” low gear mode, you can take advantage of it to improve control during hill climbs and especially descents. We hope you’ve learned something by reading this article, and we’ve got a lot of useful guides for you to read and learn all about cars!

Check out some of our other related posts:

How To Adjust Shift Linkage In An Automatic Transmission

Car Won’t Move In Any Gear Automatic Transmission

Why Does My Transmission Shift Hard From 1st To 2nd?