RV FEATURE
PETROL ENGINES
Petrol engines have been much slower to adapt new technology ( although some of the diesel tech has infiltrated petrols ).
Electronic fuel injection for petrol engines harks back to the 1980s . There have been tech improvements since , such as variable valve timing , variable valve lift and gasoline direct injection ( GDI ) – the latter is effectively the common rail for petrol engines , but GDI pressures are only up to around 200bar . None of these improvements have mirrored the ramped-up power , torque and fuel-efficiency gains in diesels , but the petrol EFI system is relatively simple , proven and trouble-free .
Part of the reason petrols are still relatively simple is because Australia is dragging the chain on petrol standards and vehicle emissions . When they improve in 2027 ( with the introduction of maximum 10ppm sulphur content in petrol ; 91RON petrol is currently a maximum 150ppm ; 95 / 98RON is 50ppm ), we may start to see more complex petrol engines becoming common ( with petrol particulate filters , for example ).
HEAVY-DUTY TOWING
Diesels are usually much more efficient than petrol models , but when it comes to heavy-duty towing ( 3000-3500kg ), that can change . Some large-displacement diesels end up as thirsty as a petrol alternative .
Yet in all other driving , especially when driving unladen in city traffic , the diesel ’ s efficiency usually puts it well ahead of similar petrols .
Diesels are more expensive to buy , but also hold their used value better than petrols .
Diesel is more readily available than petrol in remote outback areas , where diesel is more popular for rural farming communities and transport ( although petrol is usually available on all the main routes ).
Diesel is also less flammable than petrol , which can give you more peace of mind if you ’ re lugging the stuff in jerry cans on your journey .
The turbodiesel Discovery 4 is still well-respected as a long-haul tourer .
/ 09