We are about to purchase a new BT50 4X4 XTR cab chassis, dual cab. Our ball weight when towing our van will be 250kg. Can anyone shed some light as to whether an upgrade to the suspension would be advisable? Your thoughts welcome!
Are you putting anything else in it? The XT got heavier duty springs from factory than the XTR/GT so mine likes the extra weight to settle it down a bit. If you want the ride height to stay the same you'll want to upgrade - it will drop a bit with 250 on the ball. It will handle it no probs though.
Any car can support a ball weight that is within the manufacturers limits without sagging providing the owner does not put an excessive amount of additional material down the rear end with it.
Have you read the towing instructions in the car owners hand book? It may say a weight distribution hitch must be used above a certain ball the weight. If it does then don't ignore it.
A WDH will lift the rear end and ease the stress on the rear end of the chassis. That can stop excessive stress from bending the chassis if your rear end weight is excessive, stiffer after market springs can't do that, but it can also create a few problems of its own.
Keep in mind your 250 kg on the tow ball will put well over 300 kg on the rear axle axle due to leverage.
If you haven't already read the endless amount of towing and stability information on the RV Books web site, then I suggest you take the time to do it. It can answer a lot of questions and make your car/van combination a lot safer and stable on the road.