Primus Omnifuel vs. MSR Whisperlite Universal

There are some really nice expedition class stoves out there on the market right now.  One of the really nice features that's come out in the last couple of years is the "hybrid" stove, a stove that can burn not only liquid fuels like gasoline and kerosene but also nice, clean, no-priming-needed canister gas.  Perhaps the two best known stoves in this category are the Primus Omnifuel and the MSR Whisperlite Universal.  I thought I'd do a brief comparison of the two.

For more information on the individual stoves themselves, please see the following reviews:

• The Primus Omnifuel
• The Whisperlite Universal

First, travel mode.  Both come with nice stuff sacks.  Both stuff sacks have a nice zipper pouch so you don't lose any small parts.

The MSR Whisperlite Universal (left) and the Primus Omnifuel (right)

Note that the Whisperlite Universal makes a little bigger package than the Omnifuel.  This is because a) the Whisperlite Universal is the bulkier of the two and b) you get more items included with the Whisperlite Universal.

Here are the major components that come with the Whisperlite Universal:

The major components that come with a Whisperlite Universal.

Back row (L to R):  Heat reflector, inverted canister stand, and windscreen.
Front row (L to R):  burner,  fuel pump

The major components are listed in the caption above.  Of course you also get a stuff sack, a liquid fuel adapter, and a little parts baggie with spare jets, a wrench/tool, and lubricant.

By contrast, the Omnifuel:

The components that come with an Omnifuel

Basically, you just get the burner and the fuel pump (and of course the stuff sack with the wrench/tool, spare jets, and lubricant).  You (typically) don't get a heat reflector, windscreen, or inverted canister stand.  Note:  There are a lot of package deals out there with the Omnifuel; shop around.  Some packages even include a fuel bottle.  The Whisperlite Universal is typically sold separately from a fuel bottle.

The MSRP of the Whisperlite Universal is $140.  The MSRP of the Omnifuel is $160.  However, always look for deals.  I've seen all sorts of special packages and deals out there on the Omnifuel.  Be sure to shop around.

Value for the Dollar

Generally though, I'd say the Whisperlite wins on a value for the dollar basis.  There's just more included with a Whisperlite.  A windscreen is really important.  It's included with the Whisperlite Universal.  You've got to buy it separately with the Omnifuel.  I've read that there's a "built in windscreen" with the Omnifuel.  I don't buy that.  You need an external windscreen for anything more than a breeze.

Also, that little canister stand that comes with the Whisperlite Universal is actually pretty handy.

The inverted canister stand of a Whisperlite Universal

Convenience in cold weather operation

What does the canister stand buy you?  Convenience in cold weather operation with canister gas.  Yes, you could just switch to liquid fuel for cold weather operation, but there are advantages to gas like improved simmering, greater mechanical reliability, and the elimination of priming.  With the stand, you can easily invert a canister for improved cold weather operation.  Generally, inverting the canister means you can operate your stove in weather that is 20F/10C colder than you could if the canister were right side up.

The really nice inverted canister stand of the Whisperlite Universal

Notice the Omnifuel's connector just to the left of the Whisperlite Universal's canister stand.  Not only does the Omnifuel not come with a stand, but the control knob makes it hard to keep a canister inverted.  Sure, you can DIY something, but the nice, professional stand that MSR gives you is really pretty nice.

Convenience in switching between gas and liquid fuels

In terms of switching between gas and liquid fuels, the Omnfuel wins, hands down.   On the Whisperlite Universal, you have to change adapters on the end of the fuel line, and you have to change the jet.  On the Omnifuel, there's no adapter to change; you just change the jet.  Whether gas or liquid, the end of the fuel line stays the same with the Omnifuel.

Overall Build Quality

The Primus Omnifuel is a thing of beauty.  It's precision engineering at it's best.  It's almost more work of art than stove.  It's hard to sum up the difference in a photo or two, but let's take a quick look at the respective pumps.

Top:  The MSR standard pump.  Bottom:  The Primus Ergopump.

Now,  the plastic MSR pump is a perfectly serviceable pump, but there's just no comparison to the engineering marvel that is the Primus Ergopump.  The smooth, precise stroke of the Primus pump is such a pleasure.   The MSR pump feels a bit tinny by comparison.   Don't get me wrong.  I think they're both good stoves, but if you like precise Swiss watch-like engineering, the Omnifuel is for you.

Simmering

The Omnifuel has a valve at the burner, and is the better simmerer, particularly on liquid fuel.  With the Omnifuel, it's easy to simmer, and anybody, even the rankest newbie, can do it.  However, the Whisperlites are the best non-valve-at-the-burner simmering stoves that MSR makes and are a huge improvement over previous generations of the Whisperlite.  Simmering with the Whisperlite Universal takes a few tricks, like leaving a lot of air space in the fuel bottle and only pumping up the bottle with about 1/4 the normal amount of pump strokes.  With a bit of practice, the Whisperlite Universal really can simmer, but it's not as easy nor as automatic as with the Omnifuel.  The Whisperlite Universal does have a large burner head which distributes the flame well which reduces the chances of hot spotting.

Compactness

The Omnifuel has a real advantage here.  The Whisperlite Universal has a larger burner head in the first place, and for whatever reason MSR decided to go with a really stiff fuel line, a fuel line that's a real pain in the neck to pack up.  

The Primus Omnifuel is far more compact than the Whisperlite Universal

Note how in the below photo that the hose on the Whisperlite Universal sticks up in the air, supporting not only its own weight but also the weight of the canister adapter at its tip.  Now that is a stiff hose.

The Whisperlite Universal has a very stiff fuel hose, so stiff that it will stick into the air, unsupported

By contrast, the Omnifuel's hose wraps easily around the body of the stove.  NICE.

The flexible hose of the Omnifuel is easily wrapped around the stove and tucked into the folded pot supports.

Noise

The Omnifuel is just plain loud.  It's not the loudest I've ever heard, but it's definitely not going to enhance the peace of the wilderness.  

The Omnifuel with a roarer burner (left) and the Whisperlite with a ported (or baffled) burner (right)

The Omnifuel has a "roarer" type burner, and roar it does.  Now, the good thing about a roarer burner is that it's easy to clean and handles wind well.  But it is loud.  The Whisperlite, as one might surmise from its name, is far quieter.

There is however a solution to the noise problem of the Omnifuel:  You can get an after market silent cap.  The best cap I've seen is the OmniDawg silent cap from Bluewater Stove Restoration.  It's a wonderfully quiet solution that also reduces the carbon monoxide emissions of the stove, but it's typically pricey. 

An OmniDawg silent cap shown between a Primus Omnifuel (left) and an MSR Whisperlite Universal (right).

See my Omnifuel review for more information including videos on the OmniDawg silent cap.  OmniDawg silent caps are only sold through "BernieDawg's Store" on eBay.

Disclosure:  I am not affiliated with Bluewater stove restoration or "BernieDawg's Store."  I am merely a satisfied customer.  I cannot help you obtain a silent cap.  Please use eBay if you would like a silent cap for your stove.

Pot Stability

I'd say the Whisperlite Universal has the edge on pot stability.  I tested the Whisperlite Universal with an enormous (in backpacking terms) one gallon (3.8L) tea kettle.  Steady as a rock.  The pot supports on the Whisperlite Universal have a radius of approximately 94mm.  That's a pretty good sized pot support!  That's larger than the previous generation of Whisperlites which already had great pot stability.  With pot supports like that, you can use large pots for snow melting, an essential expedition task.

Now, that's not to say that the Omnifuel has poor pot stability -- far from it, but the Whisperlite Universal has the edge here.  The Omnifuel has pot supports with a radius of approximately 84mm.

Pot Compatibility

On pot compatibility, the roles are a bit reversed, at least with smaller pots.  The Whisperlite Universal with it's big burner head has trouble with smaller pots.  There is a gap of approximately 42mm from the center of the Whisperlite Universal's burner to the inner end of the pot supports.  In other words, your pot has to be wider than 84mm in order to be used on a Whisperlite Universal.  Obviously, the Whisperlite Universal wasn't meant for small, solo style mug type pots.  Unless you've got something like an MSR Espresso Star, which spans pot supports so that you can use a small pot or espresso maker, stick with a bigger pot.

An MSR Espresso Star on a Whisperlite Universal

Weight

Here's where I think the Whisperlite Universal really shines, particularly on liquid fuel.  Let's take a look at the numbers. 

Canister Gas

Primus Omnifuel        427g/15.06oz         

Whisperlite Universal  315g/11.11oz

Liquid Fuel

Primus Omnifuel        530g/18.70oz

Whisperlite Universal  369g/13.02oz

Basically, on canister gas, the Whisperlite Universal is about 112g/4oz lighter than the Omnifuel, and on liquid fuel, the Whisperlite Universal is about 161g/5.7oz lighter than the Omnifuel.  Yes, the Omnifuel has a beautiful metal pump, but you pay for it in the weight department.  Whether on canister gas or on liquid fuel, you save at least a quarter pound with the Whisperlite, and your weight savigs go up to almost 3/8th of a pound when using liquid fuel.

Note:  For the purposes of comparison, I did not include the windscreen, heat reflector, or canister stand since those only come with one of the stoves.  I wanted an "apples to apples" comparison.  Included are the stuff sacks, one jet, spare parts and tools, stove, and pump (for liquid fuel only obviously).  On the Whisperlite Universal, the appropriate adapter on the end of the fuel hose was included.

Concluding Remarks

So, which is the better stove overall?  You tell me.  :)

Seriously, it's up to you.  Take a look at the various categories I've laid out above.  It's up to you to decide which mix of price, weight, and features matter to you.  Some people won't get an Omnifuel just because it's loud.  Others won't go with the Whisperlite Universal simply because it has a plastic pump.  I can't decide for you which categories matter to you and in what way, but I hope that by laying out some facts, figures, and thoughts, this post will help you get a better understanding of which stove might better suit your needs.

Special thanks to Martin C. who helped me recover this post after it was obliterated in a Blogger error.

As always, I thank you for joining me on another Adventure in Stoving,

HJ

Technical Appendix -- Detail Weights

Whisperlite Universal Weights

	Item	Grams	Include?	Grams	Ounces	Pounds
1	Stove	232	Y	232	8.18	0.51
2	Pump	65	Y	65	2.29	0.14
3	Windscreen	60	N	0	0.00	0.00
4	Manual	57	N	0	0.00	0.00
5	Stuff Sack	35	Y	35	1.23	0.08
6	Canister Adapter	31	N	0	0.00	0.00
7	Liquid Fuel Adapter	22	Y	22	0.78	0.05
8	Reflector	17	N	0	0.00	0.00
9	Canister Stand	14	N	0	0.00	0.00
10	Spare Parts Kit	12	Y	12	0.42	0.03
11	Canister Gas Jet	5	N	0	0.00	0.00
12	Kerosene Jet	3	Y	3	0.11	0.01
13	Gasoline Jet	3	N	0	0.00	0.00
	TOTAL			369	13.02	0.81
	Upright Gas			315	11.11	0.69
	Inverted Gas			329	11.61	0.73
	Liquid Fuel			369	13.02	0.81

Primus Omnifuel Weights

	Item	Grams	Include?	Grams	Ounces	Pounds
1	Stove	348	Y	348	12.28	0.77
2	Pump	103	Y	103	3.63	0.23
3	Tool	42	Y	42	1.48	0.09
4	Stuff Sack	30	Y	30	1.06	0.07
5	Lubricant	5	Y	5	0.18	0.01
6	Canister Gas Jet	2	N	0	0.00	0.00
7	Kerosene Jet	2	N	0	0.00	0.00
8	Gasoline Jet	2	Y	2	0.07	0.00
	TOTAL			530	18.70	1.17
	Upright Gas			427	15.06	0.94
	Inverted Gas			427	15.06	0.94
	Liquid Fuel			530	18.70	1.17

Stove of the Week: Primus Omnifuel

If you want a stove that runs like a Swiss watch, then the Primus Omnifuel is your stove. It's precision engineering at it's best.  I mean this thing is a stovie's dream. Just look at that beautiful blue flame. 

The pump's action is a smooth as silk.  Everything fits together just so.  This is one high end stove.  But enough praise, let's take a look.  First, the burner.

It's a roarer style burner.  I expected it to be loud, as most roarers are, but I was pleasantly surprised.  It's really quite quiet for its type. However, one would hardly refer to the Omnifuel as quiet when the flame is on high.  The Omnifuel's three legs make it quite stable, and the pot supports are well engineered to accommodate a wide (and narrow!) assortment of pots.


The pump is sturdy aluminum, a far more robust pump than, say, a plastic MSR pump.  One interesting feature to the Omnifuel is it's rotating attachment to the fuel pump.  In order to run the stove, one rotates the fuel tank around the axis formed by the valve to the "ON" position (as seen in the below photograph).  The black grooved piece of plastic that you see immediately to the left of the pump rotates freely.

To turn the stove off, one again rotates the fuel tank around the axis formed by the valve into the "OFF" position.  In the "OFF" position, the dip tube, which would normally be in the lowest portion of the tank, submerged in fuel, now points upward and just draws air.  This air now flows out through the valve, clearing the fuel line and depressurizing the fuel tank.

It's worth noting that the threads on the Omnifuel's pump will fit Primus, Snow Peak, Sigg, MSR, Optimus, and Brunton fuel bottles.  Here, the Omnifuel is shown with an MSR fuel bottle.

The Omnifuel, as the name implies, will run on both of the standard petroleum liquid stove fuels, "white" gasoline (Coleman type fuel) and kerosene.  The Omnifuel is not designed to work on alcohol.  In a pinch, the Omnifuel can be run on unleaded automotive gasoline or diesel.  Of course it will not run as cleanly on unleaded or diesel and will require more frequent cleaning.  Use non-standard fuels like unleaded or diesel only when absolutely necessary.  The Omnifuel's manual states that leaded automotive gasoline should not be used "for health reasons."  As much as I like stoves and as much as I'd like to do a thorough review, I'm not about to personally test that health warning!  I imagine that you could run the Omnifuel on aviation gasoline or jet fuel as well, but again do so only when absolutely necessary.

Now, all the preceding regarding fuel is pretty standard fare for a multi-fuel expedition type stove like the Omnifuel, but there's another standard fuel out there that I haven't yet mentioned:  canister gas.   

The Omnifuel can run on the same gas canisters that power such popular stoves as the MSR Pocket Rocket and the Jetboil PCS.  It's really quite ingenious how Primus managed to allow not only liquid but gas fuel to be used.  The connection between the pump and the fuel line is a 7/16ths UNEF threaded male connector -- the exact same connector as on a gas stove.  If one wishes to use gas, one screws the connector into a canister of gas.  If one wishes to use liquid fuel, one screws the connector -- the very same connector -- into the pump.  Quite clever.  Indeed, other stove manufacturers, such as Brunton with the Vapor AF and Coleman with the Fyrestorm, are copying this idea.  I don't know for a fact that Primus originated the idea, but if Primus was not the first, they were among the first, and certainly the Omnifuel is a fine implementation of the idea..

For cold weather, the Omnifuel can operate with the canister inverted, that is it can operate in liquid feed gas mode.  Normally, one would invert the canister only if a stove has a pre-heat loop (aka generator) which the Omnifuel does not  However, since the Omnifuel can burn liquid fuel, which must be vaporized at the burner, it can therefore vaporize liquefied gas.  In liquid feed mode, the Omnifuel should easily operate in temperatures down to 0F/-18C, provided that you use canisters that contain some blend of either isobutane or regular butane with propane.  Canisters of 100% regular butane will not work in cold weather.  If one employs various means to keep the gas canister relatively warm and uses a winter grade fuel (a propane blend with no regular butane), one can operate the stove in far lower temperatures. The ability to run on canister gas, which requires no priming, is a big plus if the weather is really horrible and you want to cook inside your tent.  I personally do not find the idea of priming a stove inside a tent to be appealing.

The Omnifuel comes with jets with three different sized apertures, one jet for each of the three general classes of fuel:  gas (0.45mm), gasoline (0.37mm), and kerosene (0.28mm).  Each jet aperture size is optimized to burn efficiently the fuel for which it is intended.  The lighter the fuel, the larger the aperture size.  The heavier the fuel, the smaller the aperture.  While it is best to run the stove with the correct jet for a given fuel, my experience is that the stove will work reasonably well with mid-sized aperture jet on both gas and gasoline.  I have not, as of this writing, tried all possible combinations of jets and fuels.


Let's take another look at the burner.
Note the wire handle attached to the rigid portion of the fuel line.  This handle controls an "at the burner" valve.  A valve that close to the burner allows one to very precisely adjust the fuel and therefore the flame.  The Omnifuel has excellent simmering capabilities, no matter the fuel.

Now, a mild word of caution.  Stoves with a valve at the burner generally require a bit more maintenance than those that do not.  I am not saying that the Omnifuel is in any way unreliable.  It is a well designed, wonderful stove.  However, generally speaking, stoves with a simpler design, i.e. without the valve at the burner, require less maintenance.  With good quality fuels, there should be little problem.  However, were I going to some remote third-world location where the kerosene is likely to be quite unreliable as to its purity, I might be tempted to take a simpler stove, perhaps something like the MSR XGK.

At this juncture, let me make mention of a worthwhile aftermarket modification to the Omnifuel:  the Omnidawg silent cap.  The Omnidawg silent cap replaces the roarer plate in the Omnifuel's burner.  The Omnidawg greatly reduces the roaring noise of the burner.  I did a video review of the Omnidawg cap which I will link to below.  You will see me running the Omnidawg cap on an MSR Dragonfly stove because I didn't have an Omnifuel at the time I made the videos.  In actual field use, the Omnidawg cap works every bit as well on an Omnifuel as it does on the Dragonfly in the videos.  I haven't got the means to run the number of controlled trials necessary to establish this, but my gut feel is that the Omnidawg cap puts out more power than the roarer plate.  This perceived increase in power may be due to improved air gas mixing inside the cap, leading to increased efficiency in the flame.  Again, this is my gut feel only; I have no hard data on this.  Whether it increases efficiency or not, the cap runs extremely well and is very quiet.  People have asked in connection with the videos, so in hopes of heading off a lot of questions, let me publish the following information:  Omnidawg caps are available on eBay through seller "hugecanine."  The caps are hand made and are not always available.

Note:  I was approached by the producer of the Omnidawg cap and asked to do a review.  As a part of the review process I received an Omnidawg cap.  Other than the cap itself, I received no remuneration for my review.  The receipt of the Omnidawg cap was not contingent on the nature of my review (in other words I didn't have to promise to do a positive review in return for the cap).  Further, I receive no part of the proceeds from the sales of Omnidawg caps.  All comments regarding the Omnidawg cap on this page and in the linked videos are strictly my own and do not necessarily reflect the views of the producer of the Omnidawg cap.

Well, there you have it, a brief look at the Primus Omnifuel, a truly wonderful stove and a personal favorite.

HJ

The Primus Omnifuel
What's good about it?
Truly multifuel, burns all standard petroleum based fuels, including canister gas.
Precise, easy simmering
Precision engineering.
Relatively quiet for a roarer type burner
Extremely quiet with an Omnidawg cap
Powerful
Reliable
Stable
Efficient

What's bad about it?
Expensive
Relatively heavy compared to typical canister gas stoves
A bit bulky compared to typical canister gas stoves
May require more maintenance than simpler designs

Overall, highly recommended.

Other Primus Omnifuel Related Posts
Primus Omnifuel vs. MSR Whisperlite Universal -- A comparison