Diesel Lab

Conversion charts

Industry round-numbers for workshop use. Always follow the OEM manual for the exact fill.

Temperature (°C ↔ °F)

Rule: °F = (°C × 9/5) + 32 · °C = (°F − 32) × 5/9

Pressure (bar ↔ psi ↔ kPa)

Rule: 1 bar ≈ 14.5 psi ≈ 100 kPa

Torque (Nm ↔ lb-ft)

Rule: 1 Nm ≈ 0.738 lb-ft · 1 lb-ft ≈ 1.356 Nm

Power (kW ↔ hp ↔ PS)

Rule: 1 kW ≈ 1.341 hp ≈ 1.360 PS

Fuel economy

Viscosity

Density ~15°C (kg/L)

Ballpark only.

Diesel & longevity

Performance without killing parts

Workshop / engineer quick refs

Normal — general diesel tips (keep it alive)

Everyday fleet, bakkie, and workshop discipline. No fancy parts required.

• Right oil, on time. Use the OEM viscosity and approval. Dust, short trips, and tow work shorten intervals — don’t stretch because the oil looks black (diesel soot darkens early).
• Filter with the oil. Cheap filters bypass and dump dirt back through the bearings.
• Water separators. Drain on schedule. After farm bowsers or standing tanks, drain again. Water kills pumps and injectors.
• Air filter. Restricted = lazy and hot. Missing or leaking = scored bores. Highveld dust: inspect often.
• Warm under light load. Full boost on cold oil washes bearings. After a hard pull, idle a minute so the turbo sheds heat.
• Coolant system. Bleed air after any open work. Correct glycol mix. Check pressure cap and thermostat before you blame the radiator.
• Fuel quality. Contaminated diesel looks like a “tune problem.” Fix filtration before you buy additives.
• Don’t ignore limp mode. Boost leaks, clogged DPFs (where fitted), and bad sensors get worse under load — diagnose, don’t just clear codes.

Chair call: Normal is 80% of longevity. Do this before you spend on power.

Mild — better performance or consumption (smart gains)

Street-legal, reversible habits and small upgrades that help pull or litres/100 km without cooking the engine.

• Tyre pressures. Soft tyres kill economy and heat the shoulders. Set cold pressures for load (tow/passengers), not “what looked soft last week.”
• Weight and drag. Roof racks, full bakkie dust, and unnecessary ballast cost fuel every day. Remove what you don’t need for the trip.
• Smooth boost. Short-shift and early boost feel strong; steady throttle often uses less fuel for the same average speed on the highway.
• Clean intercooler / rads. Bent fins and mud packs raise intake temp and EGTs — brush and wash carefully, don’t fold the cores.
• Charge-pipe clamps. A small boost leak wastes fuel and adds smoke. Check after any pipe work.
• Service the easy power. Fresh plugs (where fitted), clean MAF/MAP as OEM allows, healthy batteries for glow/start systems — lazy electrics make lazy diesels.
• Gear and diff oil. Correct GL grade; hot fluid after mountain passes — don’t park nose-up cooking the oil. Right fluid protects and keeps driveline efficient.
• Driving style for consumption. Anticipate, fewer panic boosts, correct gear on climbs. The cheapest “remap” is your right foot.
• When you do upgrade mildly: quality intake filtration that still filters, a proven intercooler if heat-soaked, and a conservative road tune from someone who logs EGT — not a max-everything flash.

Chair call: Mild gains come from heat, air, and drag control. Consumption and usable performance both improve.

Wild — performance tips (race / strip / serious tune)

For built or mapped diesels on track, strip, or managed race use. Still education — not a how-to for illegal street use.

• Log EGT and boost. If you don’t measure, you’re guessing. Sustained high EGT melts pistons and turbos; your builder’s limit beats ego.
• Fuel supports air. Bigger turbo without pump, lines, filters, and injectors just digs a hole. Starvation kills HPFPs.
• Cooling is power. Upgraded radiator/intercooler, ducting, and fan strategy matter more after the first map. Heat soak kills the next pull — space runs.
• Tune for the fuel you actually run. Race day vs pump diesel are different maps. Wrong fuel on an aggressive file is how rods exit.
• Driveline first. Clutch, gearbox, prop, and tyres must match torque. Power you can’t put down only breaks parts.
• Matched sticky rubber. Same compound philosophy all round on AWD; pressures for the surface. Soft road tyres at 400+ Nm are a launch fail waiting to happen.
• Watch the turbo. Over-speed and oil-coking kill hybrids. Cool-down idle after hard pulls is not optional on big snails.
• Smoke is not a trophy. Excess fuel that doesn’t burn raises EGT and washes cylinders. Clean power beats black clouds.
• Build order: air + fuel + cooling + tyres + logging, then boost. Flash last, not first.
• Safety & legality. Race/strip only where allowed. No street racing. OEM and sanction rules still apply.

Chair call: Wild power without logging, fuel, and cooling is expensive scrap. Measure twice, map once.