The right fuel type depends far less on the badge than on how you actually drive.
Petrol engines remain the simplest and cheapest to repair. For city driving and moderate distances they are usually the sensible default, especially in smaller cars.
Diesel comes into its own with weight and distance. If you regularly carry loads, tow, or drive long upcountry routes, the torque and fuel economy justify the higher service costs.
Hybrids are excellent in stop-start traffic, which describes much of Mombasa and Nairobi. The main consideration is battery condition on older imports — ask for a battery health report.