First. Is it okay for you, if i will write all measures in our metric system or would you all prefer it, if i translate them into your imperial system?
And OMG I forgot one absolutly important fact. The Vehicle must be 4x4. I can't register it as a car if it tows a trailer with more the 7715lbs GVWR and is only 4x2.
MB A Class to big? Its a small car, even in germany. I'm driving a Passat which is only a little bit smaller than a E Class. Its okay.
The towing vehicle should not be bigger than a MB Sprinter (Dodge Sprinter) which is ~236"-255" long. But shorter is better.
The F250 could be too heavy for the job. Remember. I need a empty weight that must be so low, that me and my passengers have enough payload to sit in the vehicle, before it reaches 7715lbs.
The F250 with Supercab and 6 3/4 Box as 4x4 has a curb weight (what means curb weight?) of 6625lbs. But what is the empty weight (with all fluids and full gastank) as a fully loaded Lariat?
I have the chance to adjust the vehicle figures a little bit.
Vehicles who are not regulary imported by the manufacturer has no general permits.
This means, if i import a F150 by myself for example and this truck has a 4050lbs front axle and a 4800lbs rear axle, it is rated in the USA at 8200lbs. Here i can go to our TÜV and he looks on the figures and can rise the GVWR because the axles, brakes, rims and tires give him a little bit space. Normaly the brakes are the limiting fact on US vehicles here in germany. They are always a little bit small. So, if i would buy this F150 with additional aftermarket 20" rims and 275/55R20 LI117 tires, i could built in the Bear-Brake Upgradekit and this give the TÜV space to rise the GVWR to ~8500lbs and the towrating maybe to 12000lbs.
And the german rules said only one thing. If you have connected brakes the GVWR of the trailer can be 1,5x GVWR of towing vehicle.
Nothing is chiseled in stone here. This is the advantage of the german overengineering. There is always room for improvment. Rising the GVWR is a daily business for the TÜV. Only the technical properties must be given.
And the money
But to make a vehicle lighter than it is, is just and only a option provided by god.
The brakes could be the problem.
The brakepower must be given by the towing vehicle.
Regulary we have a compressor that provide the brakeair and she is given by to airlanes to the trailer and work directly on the calipers.
But a hydraulic brakesystem is possible too. In 2 ways.
1st a direct tube between towing vehicle and trailer. Is not often used because its difficult to make, expensive and somekind of slippery.
2nd is the electric to hydraulic system. We need 2 wires between the vehicles. One wire for the 12V supply for the hydraulic pump in the trailer who provides the pressure and one wire for the braking signal. (Maybe this can also be provided by one wire, i don't know, must ask the TÜV)
Is the second way not the US E2H-way? At least i found several P'n'P kits for E2H brake conversion.
The brakepower to the calipers must be given by oil or air. A pure electric actuator is not allowed, because of overheating the brakes.
The only thing every connected brakesystem must do, is to full lock the trailer brakes if the connection is terminated. For example if the trailer detaches by himself on a bump or something like this. This should minimize the damage to others.
@Festus2
Thats the fact. A complet conversion with all devices here in germany, which don't run on 12V, will cost properly 10000$ or more, if i have to change the wires. I don't know what all runs on 110V. A fridge with locks in this size will properly be around 1500-2000$. The 2 AC's at least 3000-4000$. And a gas/electric 3,7gal boiler would be at ~1000$. And than, i have the devices for the trashcan, because noone will buy them here in europe. Or, i buy many 230V to 120V converter.
Thats why i ask. If Keystone would give me the option to convert the hole electricsystem with devices to european 230V during the assembly would make it much much much easier.
But, to have a 36ft and 11inch RV with a living space of 36ft and 11inch is just a really really beautifull idea. And if i look on compareable vehicles of european manufactures and what they cost, the idea is even more beautifull. I don't have the money to spend 175000-250000$ for a german, handmade fifth wheel. Even when it has marble on the floor.