Thinking of buying a 28' travel trailer with a dry weight of 5400lbs.
Tow weights in the manual (2018 discovery 5 HSE) say 8200lbs and 770lbs tongue.

The GCVWR would help me calculate a more refined number.

thanks all.

 

I found it . Landrover call it gross train weight GTW = 6630kg

 

Nice work, and well done planning ahead for spring RVing! You're going be close on max tongue, then GVW, aren't you?

 

Here's what I am looking at........see attached pdf.
I would welcome any thoughts, ideas or suggestions.
Payload of Discovery will be tight; Just 1157lbs and 2 adults, 2 kids + tongue weight.

 

I’m new to these calculations but given you’re estimating for 300lbs of cargo in the Discovery and 500lbs of cargo in the Travel Trailer and you’re still in the 82-86% of max range you seem fine?
In my head I always think not exceeding 80% of anything is a good idea and as your numbers are only
just over and assume a fair weight of cargo and full tanks and bottle etc if seems to me your numbers are probably about 80% in real world use so for my own knowledge sticking to a 5500lb or so trailer would be ideal for me when I look to buy.

 

Like you I would rather a much bigger buffer (ie. F250) but wanted to push the numbers to see.
I'll probably take it to the CAT scales on first go and go local for first few trips to see how it handles.

 

That's a nice calculator. The trailer should have a dry tongue weight measure, but guessing not since you're using the ratio. Might be worth digging into as you get some anomalies based on layout for instance Airstream 25's have a ridiculously higher tongue weight than the 27's & some 28's.

The tricky part is trailer load distribution, the affect on tongue weight and the GVW. It looks looks right if you can keep the tongue weight at 10.75%. But if that gets up around 12% you'll be getting close to max tongue. Camping is so much fun it's easy to over do the toys. We used to run a LR3 with a 26'er but were constrained by the 400lb max tongue. We got into a Sequoia with a 35' and the only way we got that to work was empty fluid tanks and reallocating truck cargo into trailer. Perhaps something to consider until you get it dialled?

 

Yes the Discovery max tongue weight is 770lbs and the 250bhs TT tongue is 715lbs.

 

My math is a little sketchy but that sounds like 13% dry with propane & forward holds & hitch to come almost directly atop tongue. To get to 10.75% almost everything else behind the second axle?

I'm not saying this is unsafe, your process is thorough and the biggest safety device is located immediately behind the steering wheel.