Guides
Engineering & Maintenance Reference Guides (12)
Primary-source automotive guides based on SAE, API/ILSAC, ACEA, UNECE WP.29, NHTSA, and EPA standards.
Engine Oil Viscosity & Standards Explained: SAE J300, API SP, ILSAC GF-6, and ACEA Sequences
How to match cold-cranking viscosity (0W/5W), HTHS shear stability, Low-SAPS ash limits (ACEA C2/C3/C5), and LSPI protection (API SP) to your engine.
Complete Automotive Fluid & Belt Replacement Schedule (15,000 to 120,000 km)
Preventive replacement intervals for engine oil, DOT 4 brake fluid, ATF/CVT/DCT transmission fluid, coolant, spark plugs, and timing belts.
How to Read Tire Sidewall Markings: Size, Load Index, Speed Rating, DOT Age & 3PMSF
Complete engineering reference for ISO metric tire sizing (e.g., 225/45 R17 94W XL), DOT manufacture week/year, and winter 3PMSF homologation.
Used Car Pre-Purchase Technical Inspection: Paint Thickness, OBD-II Live Data & Mechanical Checks
How to verify structural integrity with a coating thickness gauge (µm), detect recently cleared fault codes via OBD-II Mode $01/$06, and test powertrain health.
Understanding OBD-II Fuel Trims (STFT & LTFT): Diagnosing Vacuum Leaks, MAF & Injector Faults
Using Short-Term (STFT) and Long-Term Fuel Trim (LTFT) percentages at idle vs 2,500 RPM to pinpoint air/fuel ratio faults without guessing parts.
12V Battery (Flooded, EFB, AGM) & Alternator Testing: Cold Cranking Amps and Voltage Reference
Open-circuit resting voltage vs State of Charge (SoC), minimum cranking voltage drop, smart alternator charging ranges, and AGM/EFB replacement rules.
Torque Converter Automatic (AT), CVT, and Dual-Clutch (DCT/DSG): Fluid Specs & Longevity Rules
Engineering differences between planetary automatics, steel push-belt CVTs, and wet/dry dual-clutch gearboxes — plus exact fluid service intervals.
Engine Coolant Chemistry Reference: IAT, OAT, Si-OAT (G12evo/G13), and Asian P-OAT Standards
Why coolant dye color is not a specification, how silicate vs phosphate corrosion inhibitors protect aluminum blocks, and refractometer freeze-point testing.
ISO 3779 VIN Decoding & Safety Recall Lookup: WMI Country Codes, Check Digit & NHTSA / EU Gate
How to decode all 17 characters of a Vehicle Identification Number (WMI, VDS, VIS), verify physical stamping zones, and check open safety recalls.
WLTP vs EPA Fuel Economy Ratings: Converting L/100 km, US MPG & UK MPG + Real-World Aerodynamics
Why WLTP laboratory numbers differ from US EPA 5-cycle tests, exact conversion formulas between L/100 km and MPG, and how speed affects drag.
Long-Distance Highway & Mountain Road Trip Checklist: Tires, Spare Wheel, Fluids & Emergency Kit
Pre-departure inspection points 48 hours before a long highway journey: full-load tire pressures, spare tire inflation, brake pad thickness, and mandatory road safety gear.
Highway Breakdown & Collision Protocol: Scene Safety, Emergency Numbers (112 / 911) & European Accident Statement
Step-by-step roadside survival and documentation protocol: hazard lights, high-visibility vests, warning triangle distance, emergency call coordinates, and photo evidence.