The Wotofo Cog MTL RTA review, and this is one has some very interesting – some might say innovative features.

Airflow is probably one of the biggest variables in vaping. From the difference between a mouth to lung draw vs direct to lung, to the subtle differences in turbulence and flavour.

Wotofo Cog MTL RTA review

Because of this, there are still new and innovative ways of controlling and shaping the air being developed.

Wotofo alongside US YouTube review Matt Culley from SMM have tried to bring something new to the airflow game.

What Can We Expect From the Wotofo Cog MTL RTA?

Wotofo are certainly one of the busier brands in vaping, and I always look forward to opening their bright green boxes, as they have a good track record with high quality, mainstream, devices.

Over the last year Wotofo have received generally positive reviews from Gaz aka FlatCapVaper for their STNG MTL RDA, Dyadic Squonk, and Recurve Dual.

The Wotofo Cog MTL RTA is another collaboration with Matt at SMM (Suck My Mod).

They have previously worked together on the Serpent SMM RTA, which Dean absolutely adored way back in 2017.

So I’m keen to see if the Wotofo Cog MTL RTA can stack up!

This was sent over free of charge for the purposes of this review. However I am not swayed by freebies, and I will report back honestly on what I find.

Matt Introduces the Wotofo Cog MTL RTA

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Inside The Box

  • Wotofo Cog MTL RTA
  • 2×2.5mm thick cotton strips
  • 0.8Ω Dual Core fused Clapton Coil N80
  • 1.2Ω Simple Wire Coil N80
  • Screwdriver
  • Spare O-Rings/Deck Screws
  • Instruction Manual

Wotofo Cog Box Contents


  • Dimensions – 22x34mm (without drip tip and 510)
  • Capacity – 3ml
  • Airflow – Gear Adjustable Bottom Airflow (0.8mm – 1.6mm)
  • Tank Material – Crack resistant PCTG and Stainless Steel
  • Deck – Single Coil

Design and Build Quality

The Wotofo Cog MTL RTA is a mostly clear tank, with the metal parts being available in 6 different colours: Black, Stainless Steel, Gunmetal, Blue, Gold and Rainbow.

Wotofo Cog colourways

It is the Stainless Steel that I received. At 22mm diameter, it is going to be the perfect fit for some of my smaller mods!

Wotofo Cog MTL RTA – Drip Tip

Starting at the top of the tank, there’s a nice vase shaped delrin drip tip that’s double o-ringed.

Top Cap

The top of the tank has a screw down cap to access your two generous fill ports. It’s actually made of two pieces, with a clear plastic cover over a steel washer.

There’s no knurling on it though, so it’s not the easiest thing to get a grip on. It has a little bit of branding with “Wotofo x Suck My Mod” (I thought Matt was going by just SMM now?) in small black writing.

Wotofo Cog MTL RTA – Tank/Chimney

The main tank section is made out of clear PCTG, so it should be pretty resistant to tank crackers. Unfortunately it does creak a little when you’re screwing everything together, so it doesn’t feel very solid.

Wotofo Cog Disassembled Another thing to note is that Wotofo actually put a little note in the box saying that you should avoid using hot water to clean the tank, so keep this in mind.

The chimney is attached to the top of the tank, and you use a broad flathead screwdriver to undo it. This allows you to take it to pieces a little more for cleaning, I only wish the rest of the tank was as easy to disassemble!

One thing to note is that there’s some rather ugly moulding on the chimney, one side is fine and show’s the Cog symbol, but the reverse has the CE mark and Vaping with Vic’s favourite “Don’t vape in a bin” symbol.

Wotofo Cog Chimney

The reason that these have such pride of place becomes clear later…

Wotofo Cog MTL RTA Deck

You’ve got a nicely laid out single coil deck, with spring loaded clamps.

It’s well thought out, including things like little raised edges to stop your coil legs from sliding out as you tighten down the clamps.

Wotofo Cog Deck

I really liked the fact the clamps are spring loaded, so they will open up on their own as you unscrew them.

One minor negative, is that in assembly one of my screws was over-tightened, and it was pretty tricky to open up.

The screwdriver that came with the tank was threatening to strip the head of the screw, so I’m glad I have a range to choose from!

Wotofo Cog MTL RTA – Airflow

Now on to the star of the show!

The airflow control is fascinating idea, rather than controlling how much air comes into the tank by a cyclops style airflow control or similar (you have two airflow slots that aren’t adjustable), Wotofo control the air coming up directly under your coil.

This is something that we’ve seen in plenty of other tanks, and usually relies on easily lost inserts, that are almost always impossible to change whilst you have a build in.

The argument being that you get better flavour by controlling the airflow here, so a little bit of faffing about is worth it.

Wotofo has tried to give you the best of both worlds, with a rotating ring on the outside that clicks into one of 5 positions.

This external ring is connected to a red plastic gear, that in turns drives a second little cog directly under your coil.

Wotofo Cog Airflow Diagram

This inner cog then has 5 differently sized holes, from 0.8mm to 1.6mm, that feed up to the adjust the airflow pointing straight up at the coil.

The rotating ring clicks positively into all of the 5 positions, and doesn’t get knocked out of place.

As for how well this performs, we shall see later.

Wotofo Cog MTL RTA Base

Flipping the tank over, you can suddenly see the reason for the regulatory marks being put on the chimney.

Rather than a flat piece of metal with room for engraving, there’s a clear plastic disk around the 510 connector.

This allows you to see the red plastic gears that control the airflow, and I have to admit it looks pretty cool. It reminds me a bit of a posh watch with a display back where you can see the movement.

Wotofo Cog Base

Although you can see torque screws on the base, these are underneath the plastic, so there’s no getting at them (normally…)

One thing I did notice is that when you start using the tank, this piece of plastic quickly fogs up with condensation, and so obscures your view anyway.

Since you can’t get into this section, I could imagine it getting a little grungy over time, especially with sweeter e-liquids.

Probably one for an ultrasonic cleaner and a long time drying when you want to clean it!

How To Fill The Wotofo Cog MTL RTA

Filling the tank is nice and easy.

As there is no knurling on the top cap, I found it was easier to remove the drip tip to allow you to place your hand flat on the top and get a bit more resistance, but you don’t have to.

Wotofo Cog How to fill

Unscrew the top cap to reveal your two generous fill ports, fill with your favourite e-liquid, and then screw the top cap back on.

If you have any issues with your wicking here, this is where you’re likely to have leaks happening, so be aware.

How To Build On the Wotofo Cog MTL RTA

  • Unscrew your clamps, they will rise on their own thanks to the springs

Wotofo Cog Unscrewing Clamp

  • Position your coil and screw the clamps down. The lower the coil, the tighter the draw

Wotofo Cog Screwing down clamp on coil

  • Snip your coil legs as close to the clamp as you can to prevent shorts

Wotofo Cog Snipping coil legs

  • Dry fire your coil and strum with ceramic tweezers as needed, to remove hot spots and get it glowing evenly

Wotofo Cog Dry burning coil

  • Take your cotton and feed it through the coil

Wotofo Cog Inserting cotton for wick

  • Cut your cotton so that it will reach to the bottom of the wick holes

Snipping cotton to length

  • Rake out your cotton to thin the ends, and cut the excess off

Thinning out cotton with tweezers

  • Place your cotton into the wick holes

Wicks placed in juice wells

  • Prime your cotton with a little bit of e-liquid

Priming cotton

  • Screw on the chimney and tank, then fill up


  • Screw the top cap on, and you’re all set!

Build Station

Close-up View Of the Wotofo Cog MTL RTA Airflow – don’t do this at home!

Because I’m naturally curious, and hate not being able to strip things into their component pieces, I decided to sacrifice the Cog so I could get a proper look at it’s workings.

Please note, doing this will totally destroy the tank, I’ve done it so you don’t have to.

Disassembled Airflow Control

You can see far more clearly what is actually going on like this. One thing that I found interesting is that the cog with the airflow holes, is set down relatively low under the deck.

This means that the air is going to have to travel up the (potentially) much wider chimney, and so it’s not as effective as having the bore changed directly below your coil.

How Does the Wotofo Cog MTL RTA Perform?

For these tests I’ve used a couple of different coils, both a simple round wire coil at 1.0Ω, and a MTL fused Clapton at 0.6Ω. I’ve tested 50/50 VG/PG Berry Ice from SVC Labs, and 70/30 Blueberry, Citrus & Pineapple from Rachael Rabbit.


Wicking (as with most RTA’s) is very important to get right, and whilst I found it was pretty forgiving, you need to make sure that your wick is not touching the deck, otherwise it will leak like crazy by going through the airflow.

Especially when you can’t access the workings of the airflow, this is something to keep in mind if you don’t want that bottom section filling up with e-liquid!

Wotofo Cog MTL RTA – Airflow and Cloud Production

I’m not going to sugarcoat this one.

Although Wotofo should be praised for trying something different, the airflow control just doesn’t work all that well.

As a committed mouth to lung vaper, I really enjoy the ‘golfball up a hosepipe‘ style of draw.

With 0.8mm being the smallest available airflow on this, I had high hopes that it would be able to give me that type of tight, satisfying, draw.

Instead it’s a relatively loose MTL vape, in fact it’s almost possible to do a DTL draw, though you will have to slipstream and let some air in around the mouthpiece.

On a 1-10 scale, from tightest to airiest vapes, this falls somewhere around the 4.5 mark.

Resetting my expectations I decided to test out the other airflow options. Maybe it would open up to give me a nice DTL draw?

Turns out all 5 of them are *almost* identical. On the 1-10 scale it ranges from a 4.5 to a 5.

One thing to note here, is that where you place your coil will make a much bigger difference to the draw that you get. Closer to the airflow hole and it will be tighter, higher up and it will be more airy.

But wherever you place your coil, the amount of control you get over the airflow from there is negligible.

I can feel a difference in the airflow, but it’s more in the quality of the air coming through, than the quantity.

I think what is happening is a combination of things, I’m not convinced that the airflow cog makes a good enough seal. This means that it’s not just how much air is going through the aperture you’ve selected, but also around it, above and below.

Secondly I think that having the short airflow channel before it hits your coil, which by necessity is the size of the largest airflow hole, gives it an opportunity to spread out and become a lot less focused.

Wotofo Cog MTL RTA – Cloud Production

I was very impressed by the amount of clouds this thing can produce!

Though as a MTL RTA, it’s not going to be fogging out any rooms.

It does manage to produce a goodly amount of thick, voluminous clouds. Very satisfying!

Wotofo Cog MTL RTA – Flavour

Happily flavour is another area where this tank shines. The liquids I tried in it were all punchy and very full flavoured.

Being set up as a MTL tank, it doesn’t achieve the sort of separation of flavours you can get on a beefy coil in a DTL tank. But all of the flavour notes were well produced and strong.

In terms of flavours, this tank performs well with sweeter juices. Plenty of sugary goodness from the vape.


  • Easy to build, with a nice deck
  • Good Flavour


  • No way of accessing the cog system for cleaning
  • Difference between the 5 airflow options is minimal
  • Ugly regulatory marks on the chimney

Final Review Verdict

So there we have it! An interesting new airflow idea by Wotofo, that doesn’t quite manage to be the “next big thing”.

The flavour it produces is really good, and of the sort of quality that I would expect from Wotofo. Cloud production is equally impressive.

My main gripe is that the airflow system just doesn’t offer enough difference in the 5 settings. Especially when you have a lot more engineering going on than normal, it has to be impressive to offset the difficulty in cleaning, not to mention my worries the mechanism will gunk up over time.

I do love how it looks, with the exception of the regulatory marks on the chimney, and I’m really enjoying the popularity of crystal clear tanks at the moment. I’m just hoping we see some more sexy clear mods to match them up with!

I do think that it’s a fascinating idea, and I hope they continue to refine it.

UK – Spend £40 & Save £12 With Code ECC
Rest Of World – Free Shipping With Code ECIGCLICK Or Free DHL Shipping With Spends over $75

Will Jameson - Ecigclick Vape Reviewer
Will Jameson

I started my vaping journey in 2017 with a little AIO kit. I’d made several attempts to give up smoking over the years, and I finally nailed it with vaping. I knew right away that I wanted to learn as much about all these devices as possible, and I quickly got into rebuildables and replaceable battery mods. I’ve always enjoyed kit and technology, so I’ve built up quite a collection of different tanks and mods. I love knowing how things work and what to do to get the best out of them, so sharing that knowledge and helping more people quit smoking is something I’m passionate about.

Build Quality
Cloud Production
Ease of Use
Replace if Lost or Damaged?
I started my vaping journey in 2017 with a little AIO kit. I’d made several attempts to give up smoking over the years, and I finally nailed it with vaping. I knew right away that I wanted to learn as much about all these devices as possible, and I quickly got into rebuildables and replaceable battery mods. I’ve always enjoyed kit and technology, so I’ve built up quite a collection of different tanks and mods. I love knowing how things work and what to do to get the best out of them, so sharing that knowledge and helping more people quit smoking is something I’m passionate about.
wotofo-cog-mtl-rta-reviewI love to see new ideas in vaping, and whilst they don't always work, it's exciting to see another way of looking at things. The Wotofo Cog is a perfectly good RTA, with great flavour. The airflow design is fascinating, and whilst it doesn't quite work here, makes me really curious to see it refined in the future!


  1. I’m new to RTA and wotofo cog is my firs contact with it. I’m using prebuiilt clapton Hellvape coils and after a day using, it is starting to tint my juice. Something like a rusty brown water. I’m worried to inhale rust or spend lots of money changing coil and cotton everyday. I’m looking for tips on that, but if you have any advice I’d appreciate that! Cheers!


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