Premixed 2-Cycle Fuel: TruFuel, MotoMix or Mix Your Own?
Published November 2, 2026 · 8 min read
Premixed 2-cycle fuel is ethanol-free gasoline already mixed with 2-stroke oil at a fixed ratio, sold in sealed cans: TruFuel, Stihl MotoMix, Echo Red Armor Fuel, Husqvarna’s premix and VP Small Engine Fuel are the common ones. It solves two problems at once: you never measure oil, and the fuel keeps for years instead of weeks. It costs several times more per gallon than mixing pump gas and oil yourself. Whether that is worth it comes down to one number, how many gallons the machine burns in a month, and this guide works through it along with what is in each can, how long it really lasts, and the 40:1 versus 50:1 trap.
What is in the can
Every canned premix makes the same three promises: no ethanol, the oil already measured, and a container that keeps the fuel fresh. The ratio and the stated storage life are what differ. These are the makers’ own statements:
| Product | Ratio | Ethanol | Storage life, in the maker’s words |
|---|---|---|---|
| TruFuel | 50:1, also 40:1 (and a 4-cycle fuel) | None | ”a minimum of 2 years from the time you open the can and for more than 5 years unopened” |
| Stihl MotoMix | 50:1, with Stihl HP Ultra oil | None | ”a storage life of up to two years”, and it “can be left in the machine during seasonal storage” |
| Echo Red Armor Fuel | 50:1, with Red Armor oil | None | ”stays stable 2 years after opening and up to 5 years unopened” |
| Husqvarna 2-Stroke Pre-Mixed Fuel + Oil | 50:1 | None | ”fuel that stays fresh for years” |
| VP Small Engine Fuel | 50:1 (2-cycle version) | None | no period stated on the pages we read |
Sources: TruFuel’s FAQ, Stihl USA’s fuel FAQ, Echo USA’s Red Armor Fuel page, Husqvarna’s 2-stroke fuel page and VP’s small engine fuel page; the same storage statements are collected with links on the 2-stroke mix ratio statistics page.
The reason canned fuel lasts is the container as much as the chemistry. TruFuel’s FAQ makes the point directly: ordinary pump gas is not suited to storage in sealed containers, and its formulation lets it be packed in a non-vented can. A vented gas can breathes humid air every time the temperature changes, and ethanol in the gas absorbs the water that comes with it. Remove the ethanol and the vent, and the fuel has very little to go wrong with.
How long pump-gas mix lasts, for comparison
Self-mixed fuel is a different product with a much shorter life. The makers’ limits:
- Stihl: do not store or use fuel older than 60 days, and preferably no longer than 30 days, even with a stabilizer (Stihl USA fuel FAQ).
- Husqvarna: do not mix more than one month’s fuel at a time; a stabilizer may extend it toward twelve months.
- Echo: do not mix more than you expect to use in 30 days, or 90 days with a fuel stabilizer.
So the honest comparison is roughly one month against two years. That gap is what you are paying for.
The cost math
Prices change by store and season, so here is the arithmetic rather than a price list. Mixing your own costs the gas plus the oil: one US gallon of gas and one 2.6 oz bottle of oil at 50:1. If gas costs $3.50 a gallon and the oil bottle $3, a gallon of self-mixed fuel costs about $6.50. Canned premix is sold in smaller containers. One price we read on 2026-11-02, Ace Hardware’s own 2-cycle 50:1 premix at $149.99 for four 1 gallon cans, works out to about $37.50 a gallon. Quart cans (32 oz) cost more per gallon again, because a quart is a quarter of a gallon.
| Use per year | Self-mixed at about $6.50 a gallon | Canned at about $37.50 a gallon | Difference |
|---|---|---|---|
| 1 gallon (a trimmer for a small yard) | $6.50 | $37.50 | $31 |
| 3 gallons (saw and trimmer, occasional use) | $19.50 | $112.50 | $93 |
| 10 gallons (weekly mowing season) | $65 | $375 | $310 |
| 50 gallons (landscaping crew, one machine) | $325 | $1,875 | $1,550 |
Swap in your own prices; the shape will not change much. Two costs are missing from the self-mix column, and they are why light users often come out ahead with cans:
- Thrown-out fuel. A homeowner who mixes a 2.5 gallon can for a trimmer that uses a gallon a year discards most of it, or worse, runs it stale.
- Carburettor work. Stale, water-laden mix is the most common reason a small engine will not start after storage. A single carburettor clean at a shop costs more than a year of canned fuel for a light user.
Read the table this way: below about 2 or 3 gallons a year, canned premix is a reasonable buy. Above about 10 gallons a year, mixing your own is clearly cheaper, and the fuel turns over fast enough that freshness takes care of itself.
40:1 or 50:1: match the can to the engine
Most canned premix is 50:1 because that is what current Stihl, Husqvarna, Echo and RedMax equipment specifies. TruFuel also sells a 40:1 mix, and its FAQ lists who each is for:
- TruFuel 40:1: Bolens, Craftsman, McCulloch, Poulan, Troy-Bilt, Weed Eater, Yard Machines.
- TruFuel 50:1: Dolmar, Echo, Homelite, Husqvarna, Maruyama, RedMax, Ryobi, Shindaiwa, Stihl, Toro.
Those are brand lists, and brands changed ratios over the decades, so the decal on the fuel cap still outranks them. The direction rule is the same as for fuel you mix yourself: 40:1 premix in a 50:1 engine is safe, it just smokes a little more; 50:1 premix in a 40:1 engine gives it 20 percent less oil than it was designed for, which is a slow way to score a piston. A 50:1 can is 2.56 oz of oil per gallon and a 40:1 can is 3.2 oz; the 40:1 vs 50:1 guide covers when a maker has approved the leaner mix for its older engines.
Where canned premix does not fit
- Dirt bikes. Many motocross bikes run richer than 40:1. Yamaha’s 2027 YZ125 and YZ250 manuals specify 30:1 and say to mix on race day. Riders also tune the ratio with the jetting. Mix your own; the dirt bike premix guide has the brand table.
- Water-cooled outboards. These use TC-W3 marine oil, a different standard from the air-cooled oil in canned premix, and many have oil injection. TruFuel says its fuel suits air-cooled outboards, which is a small group of very small motors. The outboard fuel mix guide covers the rest.
- Heavy daily use. A crew burning several gallons a day has no stale-fuel problem and a very large fuel bill. Mix your own at the right ratio and measure properly; the measuring tools guide has the cans and bottles that make it repeatable.
The hybrid most owners end up with
You do not have to pick one. The pattern that works for a lot of homeowners: mix your own in season, in a can small enough to empty within a month, and switch to canned premix for the last tank before the machine is stored. Stihl’s storage advice is to run the tank dry or use MotoMix, which can stay in the machine. Running the engine for a minute on canned fuel before storage leaves the carburettor full of fuel that will still be good in spring. The winterizing guide has the rest of the end-of-season routine, and the spring startup guide the other end of it.
Two rules for mixing the two kinds of fuel in one tank. Topping off canned 50:1 with your own 50:1 keeps the ratio right but brings back the ethanol, so the tank is now pump-gas mix with a pump-gas shelf life. Topping off with straight gas is never right: it dilutes the oil below what the engine needs.
Mixing your own instead
If the math says mix your own, measure the oil against the gas rather than pouring by eye. At 50:1 that is 2.56 oz per US gallon or 20 ml per litre; at 40:1 it is 3.2 oz or 25 ml. The calculator below does any amount in either unit, and the how to mix 2-stroke fuel guide has the full procedure:
For a Stihl owner choosing between MotoMix and Stihl oil in a can, the Stihl chainsaw gas mix guide has the model table and Stihl’s gas rules, and the best 2-stroke oil guide covers what to pour if you mix your own.
Common questions
[01] Is premixed 2-cycle fuel worth it?
For equipment that runs a few tanks a year, usually yes: canned premix is ethanol-free, already mixed at the right ratio, and keeps for years where pump-gas mix keeps for 30 to 60 days, so you stop throwing out stale fuel and stop cleaning carburettors. For a saw or trimmer that burns a gallon or more a week, mixing your own costs far less and the fuel never sits long enough to go stale.
[02] How long does premixed 2-cycle fuel last?
Per the makers: TruFuel says at least 2 years after opening and more than 5 years unopened; Echo says the same for Red Armor Fuel; Stihl gives MotoMix a storage life of up to two years. Self-mixed pump gas is a different product: Stihl says no more than 60 days, preferably 30, and Husqvarna and Echo say about a month.
[03] Can I use 50:1 premix in a 40:1 engine?
Only if the engine maker approves 50:1 for it. A 50:1 can carries 20 percent less oil than a 40:1 engine was built for. TruFuel sells a separate 40:1 mix for that reason and lists the brands it is meant for (Poulan, Craftsman, McCulloch, Troy-Bilt, Weed Eater and others). The other direction, 40:1 premix in a 50:1 engine, is safe.
[04] Can I mix TruFuel with regular gas?
You can, but there is little point. Topping off a tank of 50:1 TruFuel with your own 50:1 pump-gas mix keeps the ratio right but brings back the ethanol and the short shelf life you paid to avoid. Never top it off with straight gas: that thins the oil below the ratio the engine needs.
[05] Can I leave premixed fuel in my equipment over winter?
Stihl says MotoMix can be left in the machine during seasonal storage, and the ethanol-free canned fuels are sold on the same premise. Pump-gas mix should not be: drain the tank and run the engine dry, or replace it with canned premix and run the engine for a minute so the carburettor holds the canned fuel.