Almost every vape decision, device, coil, e-liquid, strength, traces back to one question: do you draw like a cigarette, or straight into the lungs? Get that right and the rest of the choices fall into place.
The two draw styles
Mouth-to-lung (MTL) mimics a cigarette: you draw the vapour into your mouth first, then inhale it. The draw is tight and controlled, the vapour modest. It is the natural choice for most people switching from smoking.
Direct-to-lung (DTL) is a single, open draw straight into the lungs, like taking a deep breath. It uses more power, produces far more vapour, and pairs with low nicotine strengths. It suits experienced vapers who want flavour and clouds rather than a cigarette-like feel.
Side by side
The figures below are typical values used across the industry. They are conventions, not legal limits, but they hold true for the vast majority of kits on sale.
| MTL (mouth-to-lung) | DTL (direct-to-lung) | |
|---|---|---|
| Draw | Tight, controlled, like a cigarette | Open, airy, like a deep breath |
| Airflow | Restricted | Wide open |
| Coil resistance | Above 1.0Ω (plus-ohm) | Below 0.4Ω (sub-ohm) |
| Typical power | Roughly 10–25W | Roughly 40–100W+ |
| E-liquid | 50/50, higher PG | 70/30, high-VG |
| Nicotine strength | Higher, 10–20mg/ml, often salts | Lower, 3mg/ml, freebase |
| Vapour | Modest | Large clouds |
| Best for | New switchers, discreet use, higher strength | Experienced vapers, flavour and clouds |
The middle ground: restricted DTL
Between the two sits restricted direct-to-lung (RDL): a looser draw than MTL but not fully open, typically on coils around 0.5Ω to 0.7Ω. It offers more vapour than MTL without the full power demands of sub-ohm DTL, and it pairs well with freebase e-liquids at moderate strengths. Many modern pod kits offer adjustable airflow that spans MTL to RDL.
Why strength follows draw style
This is the point that trips people up. A DTL device delivers a large volume of vapour per puff, so it is matched with a low strength, usually 3mg/ml. Put a 20mg/ml liquid in a sub-ohm DTL tank and you deliver a great deal more nicotine than intended, which feels harsh and unpleasant. Conversely, 3mg/ml in a tight MTL pod may not satisfy a heavier former smoker.
High power, low strength (DTL, 3mg/ml). Low power, higher strength (MTL, 10–20mg/ml). Our nicotine strength guide has the full table.
Which should you pick?
- Switching from cigarettes, want something familiar and discreet: an MTL pod kit with nic salts at 10mg/ml or 20mg/ml.
- Want more vapour and flavour but not full clouds: an RDL-capable pod with freebase at 6mg/ml or so.
- Experienced, chasing flavour and big clouds: a sub-ohm DTL tank with a high-VG shortfill at 3mg/ml.
Not sure which e-liquid goes with which? Start with shortfill vs nic salt vs freebase.
Sources & notes
- Coil-resistance, wattage and VG/PG figures reflect established industry convention across UK vape retailers and device manufacturers; they are typical values, not legal requirements.
- The Tobacco and Related Products Regulations 2016 set the binding limits referenced here (2ml tank, 20mg/ml maximum): legislation.gov.uk/uksi/2016/507/regulation/36
This guide gives factual information about how the products we sell are used. It is not medical or stop-smoking advice. If you have questions about your health or about quitting smoking, the NHS Better Health service is the right place to start.