1. converts (an engine or vehicle) to run on diesel fuel instead of petrol
Usage: British English spelling; American English uses 'dieselizes'; third person singular present tense
2. equips or modifies (machinery or equipment) to use diesel as a fuel source
Usage: technical or industrial context

Examples

• The fleet manager dieselises the company's vehicles to reduce fuel costs.
• Modern manufacturers often dieselise their truck engines for better efficiency.
• The workshop dieselises older petrol engines to extend their operational life.
• When the factory dieselises its equipment, it expects significant long-term savings.
• The mechanic dieselises the generator to improve its fuel economy.