A mouth to lung tank gives a tight, cigarette-like draw from coils above 1 ohm at low power. A sub-ohm tank gives an airy lung hit and big clouds from coils below 1 ohm at much higher power. Choosing the wrong one is the fastest way to hate your new setup.
The short version
- MTL tanks: coils of 1.0 ohm and up, around 10 to 18W, tight airflow, 50/50 or nic salt at higher strength.
- Sub-ohm tanks: coils below 1.0 ohm, often 0.15 to 0.4 ohm at 40W plus, wide airflow, 70/30 at 3 to 6mg.
- Both are limited to 2ml in the UK.
- Draw into your mouth first? MTL. Straight into your lungs? Sub-ohm.
The key differences
Every tank has a coil, an airflow ring and a chimney. What makes a tank MTL or sub-ohm is the resistance of its coils and how wide its airflow opens.
An MTL tank such as the Aspire Nautilus 3 or Innokin Prism T18E Pro uses coils of around 1.5 ohm or more and narrow airflow. A sub-ohm tank such as the Geekvape Z Subohm Tank 5 uses coils well below 1 ohm and opens wide for a big, airy draw.
Both hold 2ml, the UK limit for a tank containing nicotine liquid. Browse every option in vape tanks.
Resistance and power
Coil resistance and power are linked by Ohm's law. Power equals voltage squared divided by resistance. A 1.5 ohm MTL coil at 3.7V gives about 9W, a gentle heat that suits a tight draw. A 0.2 ohm sub-ohm coil needs around 3.7V to reach 70W, and pulls roughly 19A through the coil.
That is why sub-ohm tanks need a capable mod with a strong battery, while an MTL tank runs happily on a small device like the Vaporesso GTX One Pro.
Plug your own coil into the calculator below. Always stay inside the wattage range printed on the coil.
That is about 17W and draws 4.6A from the battery
Where the differences live
Look at the two tanks side by side and the clues are obvious once you know them. The airflow ring on a sub-ohm tank has wide slots; on an MTL tank, small pinholes. The coil head on a sub-ohm tank is fatter, often with larger juice holes so thick high VG liquid can reach the wick quickly.
The drip tip differs, too. Sub-ohm tanks usually have a wide bore to let lots of vapour through and cool it; MTL tanks have a narrow tip that keeps the draw tight.
Swap either part between tank types and the experience changes completely, which is why matching coils to tanks matters.
- 1Drip tip
- 2Top cap and fill port
- 3Glass and chimney
- 4Coil head
- 5Airflow ring
- 6510 connection
- 7Mod: screen and buttons
- 8Battery bay
Tanks in stock, by price
Tanks cover a wide price range. At the cheap end, the Innokin Go Max disposable tank is a £2.49 sub-ohm tank with a built-in mesh coil, a low-risk way to try lung hits on a mod you already own.
Classic MTL tanks like the Prism T18E Pro sit around £10, while the Nautilus 3 is £16.99. Full sub-ohm tanks like the Voopoo Uforce-X and Geekvape Z Subohm Tank 5 run from about £18 to £22.
All of them use a 510 connection, so they will fit most mods.
Spare glass is cheap, too.
Source: Spectrum Vaping prices.
Which tank suits you
The deciding question is how you inhale, not how big you want the clouds. If you draw vapour into your mouth first and then breathe in, like a cigarette, a sub-ohm tank will feel like trying to drink through a drainpipe. If you breathe straight in, an MTL tank will feel like sucking through a coffee stirrer.
Liquid follows the tank. MTL tanks work best with 50/50, high PG or nic salt liquids. Sub-ohm tanks work best with high VG shortfills. Nicotine is addictive, and high strength at sub-ohm power is harsh, so keep sub-ohm strengths low.
How do you take a puff?
MTL tank with a 1.5 ohm or higher coil.
Sub-ohm tank with a 0.15 to 0.4 ohm coil.
A restricted lung tank or a 0.6 to 0.8 ohm coil.
An Innokin Go Max disposable sub-ohm tank on a mod.
Test yourself
One question to check the most important pairing in this guide: tank type and liquid.
Most tank problems come from a mismatch rather than a fault. Thin liquid in a sub-ohm tank floods the coil and spits; thick liquid in an MTL tank starves the coil and burns. Strong nicotine in a sub-ohm tank is harsh enough to put you off vaping entirely.
Match tank, coil, power and liquid and everything just works. Get one wrong and nothing else can fix it.
So check all four before blaming the tank.
Which liquid suits a 0.15 ohm sub-ohm tank best?
Quick answers
What is a sub-ohm tank?
A tank that uses coils with a resistance below 1 ohm, run at higher power for a direct to lung draw and bigger clouds.
Can I use nic salts in a sub-ohm tank?
It is not recommended. High strength at high power is harsh. Use 3 or 6mg freebase in 70/30 instead.
Can I put an MTL coil in a sub-ohm tank?
Only if the coil is listed as compatible. Some coil families, like the Vaporesso GTX range, span both, from 0.15 to 1.2 ohm.
How much liquid does a tank hold in the UK?
Tanks for nicotine-containing liquid are limited to 2ml.
