What is Sub-Ohm, MTL & DTL Vaping? Easy Guide! [UPDATED 2021]

Date first published: 05/09/18. Date modified: 06/07/21

The vaping world is constantly evolving and the range of devices available to us has exploded, making it very confusing for a first time vaper to understand the differences between them. 

Even on our site, we label vaping kits as either starter MTL kits or sub-ohm DTL kits, and to a beginner vaper, they may look the same, but there are important differences.

In this blog post, we will quickly clear up the differences between sub-ohm devices, MTL devices, and newer hybrid devices, so you can be confident that the device you’re buying is right for you. Buying the wrong device is the biggest setback to those looking to switch from smoking to vaping.

If you are completely new to vaping, you may want to start with our Quick Guide to Vaping, which covers everything a beginner needs to know and some popular terminology.

Quick links:

1. DTL vs MTL: What’s the Difference?
2. What is Sub-Ohm Vaping?
3. Why Do People Sub-Ohm Vape?
4. What Are the Different Types of Sub-Ohm Tanks?
5. What E-Liquid Should I Use With My Sub-Ohm Device?
6. Is Sub-Ohm Vaping Dangerous?
7. What are Mouth-to-Lung (MTL) Devices?
8. What E-Liquid Should I Use With My MTL Device?
9. What Is the Difference Between Sub-Ohm Kits and MTL Starter Kits?
10. Conclusion

DTL vs MTL: What’s the Difference?

What does direct-to-lung (DTL) vaping mean?
DTL stands for direct-to-lung. With DTL vaping, you slowly and smoothly inhale the vapour directly to your lungs, as though you are ‘breathing’ the vapour in, then exhale a magnificent cloud. You don’t necessarily have to fill your lungs like the cloud-chasers do, but can take smaller inhales if you prefer.

What does mouth-to-lung (MTL) vaping mean?
MTL stands for mouth-to-lung. Considered much more similar to cigarette smoking than the aforementioned inhale, MTL inhales follow the principle of drawing the vapour into the mouth first and then inhaling to the lungs, before exhaling a smaller volume of vapour.

Is it better to inhale DTL or MTL when vaping?
There is no right way or wrong way to inhale, it’s down to personal preference. However, if you want to blow the biggest clouds then inhaling DTL using a sub-ohm device is the way to go. You are also unlikely to vape MTL on a sub-ohm device that combines high power and increased airflow in the tank, as it’ll probably make you cough from the amount of vapour. 

It is important to note that not all sub-ohm devices are vaped in a DTL way, nor are all MTL devices are vaped in an MTL way. This is down to personal vaping preference, but in most cases, sub-ohm devices are vaped with a DTL inhale.

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Sub-Ohm Devices Explained

Nowadays, you can get hybrid devices that can power both sub-ohm coils and MTL coils, such as the Smok Nord 4, which is a 5W to 80W device that can power 0.15Ω to 2.5Ω coils.

However, these hybrid devices provide a “restricted” DTL vaping experience. Advanced vapers looking to have the full DTL experience, should choose a dedicated sub-ohm kit such as the Geekvape Aegis Legend 2. Dedicated sub-ohm kits include powerful batteries and a tank or pod with large airflow openings, which work well with sub-ohm coils to produce large clouds of vapour.

Sub-ohm devices aren’t usually the best option for new vapers; their low resistance coils (<1 ohm) need a lot more power and produce more vapour than MTL devices, which is great for flavour intensity, but not so great when you want to vape higher strength (>0.6mg) as it will be harsh and may even give you a headache if you vape too much. Sub-ohm devices are also more likely to make a new vaper cough and be put off from vaping altogether.

Sub-ohm coils require more power to vape than coils above 1ohm. A 0.2ohm coil requires a wattage of 30-150W, but this range varies between types (the coil will say on it what wattage is best).

Why Do People Sub-Ohm Vape?

What Are the Different Types of Sub-Ohm Tanks?

Sub-Ohm Tank (with disposable coil)	Perfect for those new to sub-ohming. These tanks are traditional in style (similar to an MTL tank), with a chamber to store e-liquid and a coil of under 1ohm that can be easily disposed of and replaced. Sub-Ohm tanks tend to have a 510 connector, making them compatible with a wide range of mods. An example of this is the Freemax Fireluke 3.
Sub-Ohm Pod (with disposable coil)	Over the past year pod systems that cater to sub-ohm vapers have emerged. These are usually paired with smaller, pocket-sized devices for a more convenient sub-ohm vape. Unlike tanks which can be completely disassembled, the only part of a pod that can be changed is the coil. Pods are usually only compatible with the device or brand they’re made for, but pods that fit a 510 adaptor have been released. An example of these are pods available with the new Voopoo Drag X Pro Kit.
Rebuildable Tank Atomiser (RTA)	These tanks have a chamber to store e-liquid, but lets you build your own coil to your desired resistance on the deck/base. Some RTA’s can be built with more than one coil which provides a thicker vape. An example of this is the popular Dead Rabbit RTA.
Rebuildable Dripping Atomiser (RDA)	This tank also has a deck on which you build your own coil but there is no chamber for your e-liquid to be stored, instead you ‘drip’ the e-liquid straight onto the coil until it is saturated, pop the top back on and puff. You usually can have two or three puffs before needing to ‘drip’ the atomiser once more. Without a chamber, there is less distance for the vapour to travel, this coupled with increased airflow and a large surface area on the coil, means RDA’s produce the biggest clouds and the most flavour. An example of this is the Hellvape Rebirth RDA.
Rebuildable Dripping Tank Atomiser (RDTA)	An RDTA is a type of RTA that features a tank that stores e-liquid into which the deck sits above and wicks hang into. This is less popular than the other tanks.

It is extremely important to have a thorough understanding of ohms law before you build your own coils.

What E-Liquid Should I Use With My Sub-Ohm Device?

Typically those who vape with a sub-ohm device prefer juice with higher vegetable glycerin (VG) to propylene glycol (PG) ratio because it produces more vapour and has less of a throat hit which enables a longer DTL inhale.

Those using a sub-ohm device will prefer a lower strength e-liquid, typically no higher than 6mg/ml as more nicotine is delivered through the larger intake of vapour, and higher strengths will be too harsh with a sub-ohm coil.

Is Sub-Ohm Vaping Dangerous?

For those sticking to regular pre-built coils and using regulated devices such as those found in our range of sub-ohm kits, then it is just as safe as regular vaping devices.

If you are wanting to use a RDA or RTA to build your own coils, make sure are confident in your knowledge of ohm’s law and how different coil resistances and wattage work together. Watch tutorials, read up on them, and make sure you have the correct testing equipment and tools.

There have been cases in the past where the mod batteries, typically tube mods, used for sub-ohming have exploded due to poor care or ignorance. The FDA has put together this handy pamphlet to avoid battery explosion, which you may find useful.

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Mouth-to-Lung (MTL) Devices Explained

What E-Liquid Should I Use With My MTL Device?

A good ratio is about 50VG/50PG as this provides a smooth vape with plenty of flavour. Too higher a VG ratio will clog up the coil quickly as it is more viscous and MTL coils have smaller wicking holes, so avoid e-liquids with a VG content higher than 60%. 

On the other end of the spectrum; too high a Higher PG ratio will make the vape harsher.

Read up on the difference between PG and VG in our blog post: PG vs. VG: What are they & how do they affect the way you vape?

What Is the Difference Between Sub-Ohm Kits and MTL Starter Kits?

Sub-Ohm Kits	MTL Kits
Example Sub-Ohm Kit: Arcfox Powerful battery: Between 50W and 150W is the most common, but some kits can reach 200W and beyond!	Example MTL Kit: Nord 2 Smaller battery: Between 1W and 50W is the most common.
Tank: Regular, Pod, RTA, RDA, RDTA	Tank: Regular or Pod
Coil: Resistance less than 1ohm (<1Ω)	Coil: Resistance more than 1ohm (>1Ω)
E-Liquid: High VG | Nic Strength less than 6mg (eg. shortfills)	E-Liquid: 50VG/50PG | Nic Strength up to 18mg (eg. premixed range)

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Conclusion

• Sub-Ohm is a style of vaping that produces large clouds of vapour and intense flavour.
• Sub-ohm devices typically have a powerful ‘mod’ style battery that heats up a low-resistance coil (less than 1ohm).
• Those that use sub-ohm devices tend to inhale DTL and use higher VG e-liquid with a lower nicotine strength than an MTL vaper would use, due to the sheer amount of vapour inhaled.
• MTL devices output less power than a sub-ohm device and use a tank paired with a coil that has a resistance higher than 1ohm. This produces a draw similar to that of a cigarette, and less vapour is created.
• Beginner vapers usually use MTL or restricted-DTL vaping devices before moving on to more complex sub-ohm devices.
• It is down to personal preference what style of vaping you enjoy.