Can you confirm it is diesel and not petrol?
con-fer-MA — stress on third syllable. DIE-sel — the English word used in Italian. ben-ZI-na — stress on second syllable.
Ask the rental agent to confirm the fuel type before your first fill-up — putting the wrong fuel in a rental car is a very expensive mistake.
Mi conferma (can you confirm to me) — formal Lei form of confermare. Che è diesel e non benzina (that it is diesel and not petrol) — the conjunction che introduces the content. Diesel and benzina (petrol) are the two main fuel types.
Dove è scritto il tipo di carburante?
Where is the fuel type written?
Check the fuel cap — most rental cars have the fuel type marked
Ho messo il carburante sbagliato!
I put in the wrong fuel!
Emergency phrase — call the rental company immediately, do NOT start the engine
Il bocchettone per il diesel è più grande?
Is the diesel nozzle larger?
Yes — in Europe, diesel nozzles are wider than petrol ones, a built-in safety measure
Misfuelling (putting petrol in a diesel car) costs an average of 3,000-5,000 euros in Italy to drain and repair the fuel system — rental companies will charge this directly to your credit card. Always double-check.