50:1 vs 25:1 (Which Oil Mix Is Superior)

Using a proper oil mix ratio is a must. If you mix too much oil, the engine won’t be able to burn gasoline properly. On the contrary, not using oil will wear your engine out. 

So, which oil mixture should you use, 50:1 vs 25:1

50:1 oil mix ratio means 1 drop of oil per 50 drops of gasoline. So, naturally, 25:1 is a thicker mix and it travels slowly. Due to being fast, a 50:1 oil mix is used by current manufacturers. On the contrary, the 25:1 oil mix is very old and only suited for the old engines. 

Anyways, this was only a quick look at the whole discussion. Read along and you may find the information that you’re looking for! 

With that said, let’s jump on the wagon and head right in – 

50:1 vs 25:1 (Primary Differences)

First, we’ve to understand what these ratios mean and why it’s important for engines. That’ll help you figure out which one suits your needs the best. 

Here’s a short table we’ve made for you – 

Factors50:1 25:1
Engine 2 Stroke2 Stroke
LubricationLess More
Oil DensityLowerHigher
Price SameSame

So, which one do you prefer after reading the table? 

50:1 vs 25:1 (Thorough Comparison)

50 to 1 vs 25 to 1

This table only highlights the basics. Therefore, we’ve discussed the comparison in detail. 

Oil Density and Lubrication

A 50:1 oil mix ratio means 50 units of gas for a single unit of oil drop. Likewise, there are 25 units of gas for 1 drop of oil in a 25:1 oil mix. 

So, a 25:1 oil mix is denser.

Also, it lubricates better than 50:1. Although that much lubrication isn’t necessary for newer engines. 

On top of that, too much oil can’t be burnt properly. Thus 25:1 will create a lot of emissions. 


Viscosity means the overall flow defiance of a liquid. So, honey has more viscosity than water. 

Simply put, a mixture of 25:1 gas/oil will have more flow resistance than a 50:1 ratio. 

So, the 50:1 oil mix will move faster. This is a necessity because 2 stroke engines can wear out very fast.

A 2 stroke engine has a very high RPM and needs lubrication as soon as possible. If the oil doesn’t reach in time, the piston will get scratched. 

On the contrary, the viscosity of 25:1 is ideal for older chainsaw models. They need more lubrication and thus the 25:1 ratio provides more than enough. 

Different grades of oils have different viscosity. These numbers are called SAE grades and play an important role in mixing! 

How to Mix 50:1 or 25:1 Oil Ratio? 

We have discussed the advantages and disadvantages of both ratios. But how do I achieve a 50:1 or 25:1 ratio? 

50:1 and 25:1 Ratio Formula (Imperial System) 

In the imperial system, you only need to remember two values and calculate accordingly.

  • For a 50:1 ratio, 1 gallon of gasoline needs 2.6 fluid oz of oil
  • For a 25:1 ratio, 1 gallon of gasoline needs 5.2 fluid oz of oil 

Here’s, a small chart in imperial units to help you out – 

Gasoline50:1 Ratio25:1 Ratio
1 gal2.6 oz5.2 oz
2 gal5.2 oz10.4 oz
5 gal13 oz26 oz
10 gal26 oz52 oz

Now you can easily calculate and find out the required oil amount by yourself.

However, you can also buy pre-blended fuels and completely ignore this process if you want to. 

Here are some of our top choices – 

This will save you time and you can get started right away! 

Our Verdict

Now, better lubrication is possible in lesser viscosity thanks to science and technology. Because of them, synthetic oil is now better and it can pretty much lubricate anything! 

So, now older 2 stroke engines can run on a 50:1 oil mix. However, using a 25:1 oil mix will still be the safer option. 

Because manufacturers know their products better than anyone. That’s why you should always use the oil mix which is mentioned in your manual. 

While using 50:1 might have risks, using 25:1 will always be safe. 

And it’s better to be safe than sorry! 

Frequently Asked Questions

Question: Does 2 stroke oil expire?

Answer: Yes, it can expire over time. Usually, sealed 2 stroke oil can go as far as 5 years. However, if opened, they won’t last more than 2 years. Also, when mixed with fuel, you should use the mixture within 2-3 months. 

Question: What fuel is 2 stroke?

Answer: There’s no internal oil reservoir in 2 stroke engines. So, the oil mixes with the fuel directly. It works as a lubricant and a fuel at the same time. That’s why when there’s too much oil in the mixture; it causes a smoke emission. 

Question: How long does 2 stroke oil last once open? 

Answer: Unlike other oils, 2 stroke oils can expire very quickly. A sealed can or bottle of 2 stroke oil can last up to 5 years. However, it comes down to 2 years after it has been opened. 


And with that, we’re at the end. That was all the information we could provide on 50:1 vs 25:1. We are hopeful that you have found the info that you wanted. 

So, were you able to mix the oil properly? Share your story in the comments! 

Finally, best of luck!

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