RV FEATURE
So other than not much economy difference between petrol and diesel for some vehicles when towing , and petrols being cheaper to buy and ( often ) to maintain , why else would anyone choose a petrol tow tug over a diesel ?
A chief consideration is that modern , complex common-rail diesels do not tolerate contaminated fuel . If such an engine gets a gut full of the stuff , it isn ’ t just a matter of draining a bit of fuel and carrying on . The highly precise injectors and fuel pump have to be rebuilt or replaced at a cost of thousands of dollars . In the worst case , the damage is extensive and you ’ ll need to rebuild the engine .
Australia ’ s fuel storage and transport is not always as strictly monitored for the fuel cleanliness that a common-rail diesel demands . Water , dirt , algae , bacteria , fungus and other microbial contaminates can accumulate in fuel storage tanks , and can result in a very sick diesel engine if ingested .
Buying fuel from known-brand fuel stations , preferably the big ones that sell a lot of fuel , helps . That ’ s easier said than done when you ’ re topping up with diesel in a remote town where the fuel quality might be questionable .
There is a way around the diesel quality problem , however . If you upgrade the filtration system with an additional water separator and fuel filter , you can mostly avoid expensive diesel engine repairs .
The DPF fitted to the exhaust system of many newer diesels ( to help meet NOx emissions requirements ) can also easily become clogged when the vehicle is used for short distance runs for an extended period .
The upshot is that it is not a given that a modern diesel is a better tow-tug choice than a petrol model . Common-rail diesel engines can have more expensive problems because of bad fuel and a blocked DPF . When towing a heavy trailer , in some cases diesels are not more efficient than a petrol and usually cost more to buy and more to maintain .
If your daily driver is not used much , if at all , for city commuting , and you don ’ t stray far from the highways when on tour , a petrol tow vehicle might actually make more sense than a modern diesel .
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