I use Chevron Techroline as well as additive fuel, its a must when you are driving in areas where fuel quality is bad. I haven't needed any major fuel related service on my cars in US or India. In India its quite bad once you are on the outskirts of the city. Adulteration with naphtha and other junk including dirty tanks are commonplace on highways. The only thing that keeps my vehicle alive apart from frequent fuel filter change is STP Fuel Injector cleaner concentrate. For extreme cases I use Gumout Regane that works wonders.

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99 Gurkha with OM616 IDI turbo

2015 Gurkha with OM616 DI turbo

2014 Rexton W with OM612 VGT