Saturday 10 October 2015

Mercedes diplomacy

Allow me to introduce myself as Tech Editor of Classic Hymers, along with our small group of other technical advisers who are named in the Group introduction section at the top of the page.
All Fiat based Hymers are front wheel drive, and all Mercedes are rear wheel drive. Some of the bigger Mercedes, those who's model numbers start with a 6 or 7 also have double back wheels.
It is generally accepted not just in motorhomes but in vehicles in general, that you will get more traction, and therefore get stuck less, with a RWD vehicle than a FWD vehicle. This is a matter of simple physics - there is more weight over the wheels of a RWD vehicle and therefore more traction. This applies to any make, it is just coincidence that in Hymers all Fiats just happen to be FWD and all Mercs are RWD. However it should also be said that this only really applies to slippy surfaces like grass. If you always stay on Tarmac, then for all intents and purposes there is very little difference. 
However, with many campsites and showgrounds being grass, and the UK climate being what it is, it is only a matter of time before most motorhomes encounter wet grass, and then the differences become quite apparent. A FWD van will get stuck more often than a RWD van. Driver skill is also a big factor when it comes to not getting stuck.
When it comes to reliability of Fiat vs Mercedes, this is a hot topic that provokes much discussion and emotion because everybody understandably will be a fan of their own particular choice. It is my job to be impartial, but I think it is fair to say that Mercedes have a better reputation than Fiat, not only in motorhomes, but pretty much right across the motoring industry. Mercedes and BMW and Audi have managed to convince most of the world that theirs are the ones to aspire to. But it is not a black and white question, especially with older vehicles. It is simply wrong to say that all Fiats will break, and Mercs never will. All engines from all major manufacturers are capable of long reliable service - otherwise those manufacturers would have disappeared long ago. The other thing to consider is why are some manufacturers more expensive than others, and why are people willing to pay the premium? However there are also historical factors. Today, Mercedes come in the bottom half of the reliability tables, but back in the 80's and early 90's, their old engines had a justifiable reputation for being the best. They dominated taxi fleets all over the world and whole governments used nothing else for their emergency and military fleets. This reputation was based almost entirely on the qualities of the diesel engines Merc used at the time - in particular the 5 cylinder 3 litre model that is found in all pre 95 merc Hymers, and there is no doubt that this engine has a great reputation - and not only amongst motorhome owners.
With regard to post 95 Merc models, also known as Sprinters - well in a nutshell they are also no different. Technology moves on, and 1995 saw Mercedes introduce a huge raft of new models, prompting Hymer and many other manufacturers to also introduce new ranges based on the new chassis, and Fiat also brought in new chassis.
The other thing that is often not mentioned is that there was a big change in 1997 in driving licence regulations. Prior to 97 if you passed your test, you could drive anything up to 7.5t. After 97 this came down to 3.5t, resulting in a big move in the motorhome industry to build vans that were under this weight, so as to appeal to the maximum number of customers. So this meant that weight became all important, and it is a simple fact that a FWD chassis is quite a few kilos lighter than it's RWD equivalent. Cost also became an issue and the result is that pretty much all the modern vans you see on the road today are under 3.5t and powered by FWD Fiat Ducato chassis. In modern vans, Fiat rule the roost!
So given that you said you want an automatic, and that you often visit showgrounds, if you fancy the retro look of the pre 95 Hymers, then you should look at any auto pre 95 Hymer with a designation that starts with S5xx, S6xx, or S7xx The S denotes Mercedes chassis, the first number denotes the approx length, and the last two numbers the layout. You might also look at post 95 models that feature the newer Sprinter chassis, which I believe feature a semi auto gear box which offers the best of both worlds and are a dream to drive.
Good luck!