Home How Much Oil for 2.5 Gallons at 40:1?

How Much Oil for 2.5 Gallons at 40:1?

You Need:
8.0 fl oz
(237 mL or 0.237 liters)
of 2-stroke oil for 2.5 gallons of gasoline at 40:1 ratio

How to Mix 2.5 Gallons at 40:1

  1. Pour 2.5 gallons of fresh gasoline into a clean, approved fuel container
  2. Measure 8.0 fl oz (237 mL) of high-quality 2-stroke oil
  3. Add the oil to the gasoline (not gasoline to oil)
  4. Cap the container and shake vigorously for 30 seconds to mix thoroughly
  5. Label the container with the mix ratio and date
  6. Use within 30 days for best performance

40:1 Mixing Chart

Quick reference for other amounts at 40:1 ratio:

Gallons Oil (fl oz) Oil (mL) Oil (Liters)
1 3.2 fl oz 95 mL 0.095 L
2 6.4 fl oz 189 mL 0.189 L
2.5 (current) 8.0 fl oz 237 mL 0.237 L
3 9.6 fl oz 284 mL 0.284 L
4 12.8 fl oz 379 mL 0.379 L
5 16.0 fl oz 473 mL 0.473 L
6 19.2 fl oz 568 mL 0.568 L
10 32.0 fl oz 946 mL 0.946 L

What Equipment Uses 40:1 Ratio?

The 40:1 ratio is common for older outboard motors, some string trimmers from the 1990s, and vintage chainsaws.

→ Complete 40:1 Ratio Guide

Important

Always use the fuel ratio specified in your equipment's owner's manual. Using the wrong ratio can cause engine damage from inadequate lubrication (too lean) or fouled spark plugs and carbon buildup (too rich).

Need a Different Amount or Ratio?

Use our full calculator for custom amounts:

Go to Full Calculator

Related Questions