Free Automotive Tools
Interactive calculators, fitment tools, and printable checklists. Built for mechanics, DIYers, and anyone who'd rather check the math once than redo a bad install. No signup, no ads, no analytics — every tool runs on your device.
Bar to PSI Converter
Convert tire pressure between bar, PSI, and kPa live. Door-jamb sticker decoder, common car/truck pressures, severity badge. NIST-exact factor. Reviewed by Mike Reeves, ASE Master Tech.
Open toolWheel Offset Calculator + Visualizer
Compare stock vs new wheel setup with poke/tuck delta, backspacing, plain-English fitment severity, and SVG fender visualizer. Spacer-aware. Reviewed by Mike Reeves, ASE Master Tech.
Open toolTire Height & Diameter Calculator
Compare any two tire sizes — diameter delta, speedometer error %, revs per mile, lift estimate with vehicle presets, and a branded PDF spec sheet. Plus-size helper built in. Reviewed by Mike Reeves, ASE Master Tech.
Open toolTire Diameter Calculator
Get any tire's overall diameter (height) from its sidewall code — metric or flotation — with section height, circumference, and revs per mile. Includes a tire diameter chart and side-by-side compare. Reviewed by Mike Reeves, ASE Master Tech.
Open toolTire Ply Rating + Load Index Chart
Look up any sidewall code or load index — Load Range letter, ply equivalent, max PSI, and capacity in lb/kg. Interactive filter by passenger / LT / trailer / heavy-duty. Live load-index slider, branded PDF, embeddable widget. Reviewed by Mike Reeves, ASE Master Tech.
Open toolTrailer Tire Load Range Chart
What an ST trailer tire actually carries, by size and load range — the full Tire and Rim Association load table from 15 to 80 psi. Checks your loaded trailer against total tire capacity and gives you the margin, plus a printable one-page PDF and embeddable widget. Reviewed by Mike Reeves, ASE Master Tech.
Open toolRecommended Tire Pressure Lookup
Year/make/model PSI lookup — 100+ US vehicles from owner-manual and OEM tire-and-loading data. Live load + ambient-temperature correction, source link per vehicle, branded PDF spec sheet, embeddable widget. Reviewed by Mike Reeves, ASE Master Tech.
Open toolTire Pressure Calculator (Load-Based)
Compute the minimum cold PSI to carry a load — per axle, with towing tongue weight, load index, load range, and dually support. TRA load-inflation formula for trucks, trailers, and plus-size tires the door sticker no longer covers. Branded PDF, embeddable. Reviewed by Mike Reeves, ASE Master Tech.
Open toolBolt & Lug-Nut Torque Calculator
Compute tightening torque with the industry T = K × D × F formula for any bolt or wheel-stud size, grade, and lubrication. Live ft-lb / Nm / in-lb display, star-pattern reminder. Reviewed by Mike Reeves, ASE Master Tech.
Open toolLug Nut Torque Chart by Make & Model
Search any car, SUV, or truck for its OEM lug-nut torque spec and stud size — a sortable, filterable reference table plus a stud-size fallback chart, star-pattern reminder, and branded printable PDF. Embeddable. Reviewed by Mike Reeves, ASE Master Tech.
Open toolMetric Bolt Torque Chart
The full M6–M24 chart in Class 8.8 / 10.9 / 12.9. Recomputes live for dry / oiled / anti-seize, one-tap Nm ↔ ft-lb, tap-to-pin spec card, and a branded full-chart PDF. Embeddable. Reviewed by Mike Reeves, ASE Master Tech.
Open toolFt-Lbs to Nm Torque Converter
Convert torque between ft-lb, N·m, and in-lb live in three linked fields. Mechanic-flavored: lug-nut + spark-plug + oil-drain presets, wrench-class chip, branded PDF. NIST-exact factor. Reviewed by Mike Reeves, ASE Master Tech.
Open toolJump Start Order — Animated Diagram
Step-by-step animated jumper-cable connection diagram with 5 scenarios (car-to-car, jump pack, hybrid, EV, motorcycle), 'why this order' callouts on every step, and a printable wallet card. Reviewed by Mike Reeves, ASE Master Tech.
Open toolUsed Car Inspection Checklist
61 ASE-shop inspection points across 9 sections — interactive on your phone in the seller's driveway. Live deal-score, walk-away alerts for title/frame/engine red flags, and a one-page PDF report with your vehicle data. Reviewed by Mike Reeves, ASE Master Tech.
Open toolTowing Capacity Calculator + VIN Lookup
Three ways to find your tow rating — year/make/model presets for 40 popular trucks/SUVs, free NHTSA VIN decode, or manual GCWR/GVWR/curb entry. Live payload + tongue weight, 80% safe-tow zone, branded PDF, embeddable. Reviewed by Mike Reeves, ASE Master Tech.
Open toolTrailer Ball Size Chart
All four ball sizes with shank diameter, shank length and what real parts are actually rated for — because capacity comes from the forging, not the dimensions, and two identical-looking 2-5/16 inch balls are published at 10,000 and 30,000 lb. Checks your coupler, your loaded weight and the hole in your ball mount, and gives the nut torque nobody else prints. Branded PDF, embeddable. Reviewed by Mike Reeves, ASE Master Tech.
Open toolTowing Capacity by VIN
Decode any VIN — Ford, RAM, Chevy, GMC, Toyota and more — to find your truck or SUV's tow rating free. NHTSA decode + OEM tow-guide math, live payload + tongue weight + 80% safe-tow zone, printable tow card. No dealer signup, no inventory funnel. Reviewed by Mike Reeves, ASE Master Tech.
Open toolToyota Maintenance Schedule
Enter your Camry, Corolla, or RAV4 mileage and see what's due now — oil, plugs, coolant, filters — from Toyota's fixed-interval schedule. The 0W-16 oil catch and 'lifetime' fluid truth flagged. Branded PDF, embeddable. Reviewed by Mike Reeves, ASE Master Tech.
Open toolHonda Maintenance Schedule + Minder Codes
Civic, Accord, CR-V maintenance by mileage with the Maintenance Minder codes (A, B, 1–6) decoded — read exactly what your dash wrench means. Honest CVT-fluid stance. Branded PDF, embeddable. Reviewed by Mike Reeves, ASE Master Tech.
Open toolHonda Civic Maintenance Schedule
Civic-specific schedule by mileage and engine — the 2.0L's 110k plugs vs the 1.5 turbo's 100k, honest CVT-fluid timing, and the Maintenance Minder codes (A, B, 1–6) decoded. Branded PDF, embeddable. Reviewed by Mike Reeves, ASE Master Tech.
Open toolHonda Accord Maintenance Schedule
Accord-specific schedule by mileage and engine — 1.5 turbo (CVT) vs 2.0 turbo (10-speed), spark plugs at 100k, honest transmission-fluid timing, and the Maintenance Minder codes (A, B, 1–7) decoded. Branded PDF, embeddable. Reviewed by Mike Reeves, ASE Master Tech.
Open toolFord Maintenance Schedule
F-150, Escape, Explorer schedule by mileage and engine — EcoBoost vs 5.0L plug intervals done right, plus the AWD PTU 'lifetime' truth. Intelligent Oil-Life Monitor explained. Branded PDF, embeddable. Reviewed by Mike Reeves, ASE Master Tech.
Open toolMazda Maintenance Schedule
Mazda3 and CX-5 schedule by mileage, straight from the official Scheduled Maintenance table — including the CX-5 Turbo's 40k plug interval and FL-22 coolant. Schedule 1 & 2. Branded PDF, embeddable. Reviewed by Mike Reeves, ASE Master Tech.
Open toolVW Maintenance Schedule
Jetta, Tiguan, Atlas, GTI, and Golf R schedule by mileage from VW's published US table — including the DSG and 8-speed fluid services VW actually prints (80k, not 'lifetime'), 80k vs 40k plug intervals, and the 2-year brake-fluid rule. Branded PDF, embeddable. Reviewed by Mike Reeves, ASE Master Tech.
Open toolSpark Plug Gap Chart by Vehicle
Search any engine for its factory gap in inches, mm, and thou at once — plus a re-gap verdict per vehicle (fine-wire plugs you must not bend vs. adjustable ones), NGK's −.004 in per 50 hp power-adder rule applied live, and a mileage-based erosion estimate. Branded PDF, embeddable. Reviewed by Mike Reeves, ASE Master Tech.
Open toolEngine Oil Viscosity Chart
Drag your coldest morning across all six SAE winter grades and see which ones are actually tested to pump there — the current J300 limits, not the pre-1999 table most charts still print. Compare any two grades side by side, plot viscosity at any temperature from a data sheet, °F or °C throughout. Branded PDF, embeddable. Reviewed by Mike Reeves, ASE Master Tech.
Open toolLexus Maintenance Schedule
ES, RX, and NX schedule by mileage with the engine-specific spark-plug intervals charts get wrong — 60k on the 3.5 V6, 40k on the 2.4 turbo, 120k on the 2.5 four. Lexus's published 3-year brake-fluid change surfaced. Branded PDF, embeddable. Reviewed by Mike Reeves, ASE Master Tech.
Open toolWindshield Wiper Size Finder
Driver, passenger, and rear blade sizes for 73 vehicle generations, scoped by year range rather than nameplate, because a Camry is 26/18 through 2017 and 26/20 after it. Not listed? Measure yours and get the size to buy. Holding the wrong size? A will-it-fit verdict with the exact percentage of sweep you would lose. Branded PDF, embeddable. Reviewed by Mike Reeves, ASE Master Tech.
Open toolCar Battery Voltage Chart
Type in your multimeter reading and get the state of charge behind it — corrected for battery temperature, which no other chart does and which is worth 17 points on a freezing morning. Four test contexts, because 12.4 V at rest is 75% and 12.4 V with the engine running is a dead alternator. Flooded, AGM and lithium curves, plus the temperature-adjusted load-test minimums. Branded PDF, embeddable. Reviewed by Mike Reeves, ASE Master Tech.
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