Nasty Fast Parts · Two-Stroke Tech Tools
Premix v84
Get your gas-to-oil mixture right. Start with the oil you have and find out how much gas to add—or start with your gas and find out exactly how much oil you need.
Shared Builds · Jetting / Gearing / Premix
1. Choose your mix ratio
: 1
For 40:1, use 40 parts gasoline for every 1 part oil, by volume.
2. How much gasoline do you have?
3. Your mixture
Add this much oil
16.00 US fl oz
To 5 US gallons of gasoline at 40:1
Mixture total: 5.13 US gal
Engine Oil Ratio Guide · Shared Build Data
Suggests a starting premix ratio from RPM, engine size, cooling, and hot oil viscosity. It follows the types of inputs used by RatioCalc11H.xlsx, with a simplified, explicitly provisional model.
Saved engineManual / no build
Displacement—
Peak RPM—
Estimated BMEP—
Estimated flywheel HP—
Load a named build to use Jetting / Engine Simulator data.
Estimated starting ratio, gasoline : premix oil—Enter engine information.
This is a comparison heuristic, not a direct recalculation of every RatioCalc formula or a proven minimum oil requirement. The workbook accounts for carb air speed, oil viscosity at high temperature, temperature assumptions, riding style and engine details. Larger displacement does not automatically guarantee lower oil demand. Follow your engine builder, oil manufacturer, and engine's specified minimum oil quantity. Oil injection systems require their own procedures.
Gasoline-to-oil ratios are measured by volume. Results calculate oil as an addition to the gasoline you entered, not as a replacement for part of it. Volumes are idealized; temperature, measurement error, and container markings can affect actual mix. Always follow the engine manufacturer's oil requirements.