The Mercedes Viano is essentially a van with more seats, so there's loads of interior space..rash tested in 2008 by Euro NCAP the Viano scored four stars for adult safety and three for children. The mechanical build quality of the Viano is very high as it shares a platform with Mercedes' highly dependable commercial van, the Vito.
Expert hypermiler Wayne Gerdes set a new Guinness World Record for fuel economy in a 2013 Volkswagen Passat TDI, a diesel-powered midsize sedan. The Passat used just 104.94 gallons of fuel for an average fuel economy of 77.99 miles per gallon. That beats the old record, established in 2009 by an Australian couple. Over their 9,505-mile trip, Helen and John Taylor averaged 67.90 miles per gallon in a 2009 Volkswagen Jetta TDI.
The Adblue fluid lasts up to 10,000 miles in the VW Touareg TDI and up to 10-15,000 miles in the Audi Q7 TDI. The Touareg has a 4.5 gallon (16.9L) tank and the Audi Q7 has a 6 gallon (23 liter) Adblue tank.ome of the technology on the CATA 3.0L TDI engine is common rail fuel injection which uses extremely rapid piezoelectric (like the vibrating sonicare toothbrush head) injections of fuel at about 29,000 psi! To compare, the average gasoline engine injects fuel at about 60 psi. The turbo is a VNT variable nozzle turbo.