Auto Mechanic Math: Displacement, Compression Ratio, Gear Ratios, Tyre Sizes & Labour Quotes

What you'll build

What you will be able to do

Each lab ends with a concrete result that you build yourself and the checker confirms, cell by cell.

• Calculate the swept volume of six engines from bore, stroke and cylinder count, express it in cc, litres and cubic inches, and size a classic V8 from inch specs.
• Calculate swept and clearance volume per cylinder for four engines, turn them into compression ratios and work out the chamber volume a target ratio needs.
• Turn a dyno torque curve into horsepower, N·m and kW, find the power peak and draw the classic torque-and-power chart.
• Combine six gear ratios with the final drive, turn engine rpm into wheel rpm and road speed in km/h and mph, and find the engine rpm at cruising speed in top gear.
• Split six tyre codes into width, aspect ratio and rim size with text functions, calculate each overall diameter, compare it with the stock size and work out the true speed when the speedometer shows 100.
• Convert US mpg to L/100 km and back, then turn the fuel price per gallon into a cost per km and a yearly fuel bill for five customer vehicles.
• Convert tread depth from 32nds of an inch to mm, flag every wheel position where a pad, rotor or tyre is past the shop threshold, count the positions to fix and colour them on the inspection sheet.
• Price four labour operations and four parts, apply the shop-supplies charge with its cap, add sales tax, total the quote and chart what the customer pays for.