IMHO its all about usable floor space in a wfp application.
The LWB Vivaro has approx a 400mm longer load length than the SWB Transit. 400mm on a measuring tap is nothing but its massive in the back of a van.
Saying that, a swb Transit is fine for a 2 man system with a 650 liter tank. The Transit is fractionally shorter than my swb Citroen Relay but in a day to day working environment I doubt we would notice the difference.
Our 650 liter tank is placed length ways which I imagine would probably be best in the Transit as well to not overload the front axle.
The Fiat Ducato uses the same engine as the Boxer and Relay, a 2.2hdi PSA engine. Its also the same engine as the Ford Transit is.
They just have different names. Fiat also use the Iveco 2.3 engine, but as it much heavier the payload of the same van with that engine is lower.
The Ducato/Relay/Boxer from the facelift in 2006/7 are galvanized dipped so don't appear (as yet) to suffer with corrosion as do the earlier model vans (1994 - 2005). I'm not sure if Ford have improved their anti rust protection since moving the factory to Turkey or not. Time will tell.
The latest models (Ducato etc) have a slightly longer load length as well when compared to the previous models. Its still well short of the lwb Vivaro.
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