What is "diesel bug" and how can it be prevented?

A. An additive in low-sulphur ULSD that causes filter blockages in warm weather

B. Microbial contamination (bacteria, fungi, yeast) that lives at the fuel/water interface in the tank — produces black sludge that blocks filters. Prevention: keep tanks full (reduces condensation), use biocide additive, drain water from primary filter regularly, check tanks annually

C. Rust particles from an old steel tank — only affects vessels over 20 years old

D. A chemical degradation of diesel that turns it to gel in cold weather — only a problem in winter

A. Diesel engines work at lower compression ratios than petrol engines for safety

B. Compression ignition: diesel fuel is ignited by the heat of highly compressed air (compression ratio ~22:1) — no spark plugs are used. Fuel is injected into the compressed air at the moment of ignition

C. Diesel engines use spark plugs but fire in a different sequence to petrol engines

D. Diesel engines use carburettors to mix fuel and air before compression

A. Compression, ignition, induction, exhaust — the compression happens before air enters

B. Ignition, compression, induction, exhaust

C. Induction (air in): piston down, air drawn into cylinder. Compression: piston up, air compressed to high temperature. Power (ignition): fuel injected, combustion drives piston down. Exhaust: piston up, exhaust gases expelled

D. Induction, power, compression, exhaust