Estimates for planning
Every figure on this site is an estimate. Exact relationships such as displacement or gear ratios are only as accurate as the measurements you type in, and empirical formulas such as quarter-mile or 0-60 estimates describe average results: a real car can land well away from them. Typical values such as drivetrain loss or fuel consumption per horsepower are ranges, not facts about your engine.
Confirm before you buy or install
Use the results to narrow down options, then confirm measurements, specifications, clearances and fitment with your wheel and tire shop, your engine builder or the parts manufacturer before buying, modifying or installing anything.
Not professional advice
Gear Toolbox is not a mechanic, an engineer or a parts supplier, and nothing on the site is professional, engineering or mechanical advice. The site does not give advice on safety-related systems.
Emissions and local rules
Engine modifications may be subject to emissions laws in your state and to other local rules. Check the regulations that apply to your vehicle. Performance estimates refer to closed courses such as a dragstrip, never to public roads.
Liability
Use of the calculators is at your own risk. The terms of use set out the limitation of liability. If you find a mistake, please tell us.