New Truck - Is My Math Right?
Hi Everyone, My wife and I recently purchased a truck for towing. I've been running the numbers to see which RV's we could purchase and would appreciate you spot checking my math. Here are some...
Forum Discussion
Payload and tongue weight don’t equate.
A WD hitch will leave about 68-75% of the TW on the tow vehicle..
An 1,100-lb TW is going to have about 400# effect on each TV axle. That’s car, SUV or van territory.
Payload has a different effect. Load it up and scale it. See for yourself.
The stiffer the spring package, the worse it will be unless the cab & bed are sufficiently loaded ON EVERY TRIP.
An “ideal” to work towards is where the tow vehicle is roughly 50/50 in weight division before hitching. Afterwards, 10% more on the rear axle.
The old rule was of one-thirds in how to set a WD hitch. 1/3 of the TW to each point (2 on RV, one on TT).
Stiffer the TV suspension, the less stiff need be the WD bars. TW IS NOT the determinant.
But it still comes down to how heavily the TV is loaded prior to hitching.
Pickups are already nose-heavy. Unstable. Towing only makes that worse.
Get the bed load on or ahead of the drive axle. Secured tightly.
The trailer needs to be level after WD is set. TV slightly tail down US NOT a concern.
Scale readings are ALWAYS max fuel, full propane & full fresh water. That baseline is easily replicated.
Is there about 400# or more remaining capacity for each axle when loaded for camping, all passengers aboard and unhitched?
Much more than that IS NOT beneficial. Is detrimental.
I run mine right at RAWR. My pickup carries 1200-lbs constantly. The 35’ trailer is such that getting the Steer Axle back close to solo value is possible. 2WD with IFS makes that easier.
“Weight” isn’t the problem. It’s in having steering, braking and handling relatively unaffected after hitching.
1). Steering IS different, granted. But that’s more to do with TV loading.
2). Does it stop faster once hitched? If it doesn’t, failure lays in the above (given correct brake action).
a). Empty pickup bed (weight ratio) and nose-down trailer means braking is 50% and less of what it should be. I hope it’s obvious WHY.
3). Tire pressure is ACCORDING TO LOAD. Not over or under book value, as either WORSENS all aspects of performance. Better shocks, etc, is the help to consider. Trailer leaf springs should be dumped for torsion axles.
a). TT tires always to max value.
Driver bad habits solo are also a concern. Braking into corners. Failure to slow sooner. Failure to stay below traffic flow. Failure to maintain adequate separation distance. Start now. Towing is not the time to begin.
Given what I see on the highways, the above are nowadays UNIVERSAL failures. Kick the teenager out of the drivers seat.
.
A WD hitch will leave about 68-75% of the TW on the tow vehicle..
An 1,100-lb TW is going to have about 400# effect on each TV axle. That’s car, SUV or van territory.
Payload has a different effect. Load it up and scale it. See for yourself.
The stiffer the spring package, the worse it will be unless the cab & bed are sufficiently loaded ON EVERY TRIP.
An “ideal” to work towards is where the tow vehicle is roughly 50/50 in weight division before hitching. Afterwards, 10% more on the rear axle.
The old rule was of one-thirds in how to set a WD hitch. 1/3 of the TW to each point (2 on RV, one on TT).
Stiffer the TV suspension, the less stiff need be the WD bars. TW IS NOT the determinant.
But it still comes down to how heavily the TV is loaded prior to hitching.
Pickups are already nose-heavy. Unstable. Towing only makes that worse.
Get the bed load on or ahead of the drive axle. Secured tightly.
The trailer needs to be level after WD is set. TV slightly tail down US NOT a concern.
Scale readings are ALWAYS max fuel, full propane & full fresh water. That baseline is easily replicated.
Is there about 400# or more remaining capacity for each axle when loaded for camping, all passengers aboard and unhitched?
Much more than that IS NOT beneficial. Is detrimental.
I run mine right at RAWR. My pickup carries 1200-lbs constantly. The 35’ trailer is such that getting the Steer Axle back close to solo value is possible. 2WD with IFS makes that easier.
“Weight” isn’t the problem. It’s in having steering, braking and handling relatively unaffected after hitching.
1). Steering IS different, granted. But that’s more to do with TV loading.
2). Does it stop faster once hitched? If it doesn’t, failure lays in the above (given correct brake action).
a). Empty pickup bed (weight ratio) and nose-down trailer means braking is 50% and less of what it should be. I hope it’s obvious WHY.
3). Tire pressure is ACCORDING TO LOAD. Not over or under book value, as either WORSENS all aspects of performance. Better shocks, etc, is the help to consider. Trailer leaf springs should be dumped for torsion axles.
a). TT tires always to max value.
Driver bad habits solo are also a concern. Braking into corners. Failure to slow sooner. Failure to stay below traffic flow. Failure to maintain adequate separation distance. Start now. Towing is not the time to begin.
Given what I see on the highways, the above are nowadays UNIVERSAL failures. Kick the teenager out of the drivers seat.
.
