I used one of these performance enhancers on my 2002 E320 Estate (station wagon in the US) straight six turbo diesel in the UK and picked up economy and power.
They will ship to the US.
Via a PM I could explain other mods to other vehicles.
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TV - 2012 Dodge 2500 4x4 Cummins HO, automatic, Centramatics, Kelderman level ride airbag suspension, bed shell
2014 31' Classic model 30 twin beds, 50 amp service, 900 watt solar system, Centramatics, Dill TPMS, disc brakes, 16" tires & wheels