Question 1

1. How many ounces of oil for 2.5 gallons at 50 to 1?

Accepted Answer

A 2.5 gallon mix needs 6.4 fluid ounces of oil, about 189 milliliters.

Question 2

2. Can I use 50 to 1 fuel in a 40 to 1 engine?

Accepted Answer

It will run, but it should not become a habit. The engine receives less oil than intended, and wear adds up quietly. Mix the ratio your manual specifies.

Question 3

3. What does a 50 to 1 ratio mean in simple terms?

Accepted Answer

The finished fuel contains 50 parts gasoline for every 1 part of two stroke oil, measured by volume. In practice, each gallon of gasoline gets 2.56 fluid ounces of oil, and each liter gets 20 milliliters.

Question 4

4. How much oil do I add to 5 gallons of gas for a 50 to 1 mix?

Accepted Answer

Add 12.8 fluid ounces of oil, about 378.5 milliliters. The finished can then holds about 5.1 gallons of mixed fuel, because the oil is added on top of the gasoline.

Question 5

5. What happens if I add too much oil?

Accepted Answer

The engine will usually still run, but it smokes more, fouls the spark plug faster and builds carbon in the exhaust port and spark arrestor screen. Drain and remix if the error is large.

Question 6

6. What happens if I add too little oil?

Accepted Answer

Too little oil is the dangerous direction. Friction and heat build up on the piston and cylinder, scoring the surfaces and, in the worst case, seizing the engine solid. If a batch is short on oil, add the missing amount and shake the can before using any of it.

Question 7

7. Can I use regular motor oil instead of two stroke oil?

Accepted Answer

No. Car engine oil is not made to burn cleanly in a two stroke engine, and it leaves heavy ash and deposits. Use oil labeled for two stroke engines, ideally one carrying a JASO FD or similar rating.

Question 8

8. How long does mixed 50 to 1 fuel stay usable?

Accepted Answer

Plan on about 30 days for fuel you mix yourself, longer when a stabilizer is added at mixing time. After that, the gasoline degrades and starting problems become more likely. Labeling each can with its mix date is the easiest way to keep track.

Automotive Tools

50 to 1 Gas Oil Mix Calculator for Two Stroke Engines