Rear Axle Weight

derh20 wrote:
My question is, would I increase the weight limit by replacing the stock tires with tires that have a higher weight limit?

No, but it will make the ride much harsher.

"Gross Axle Weight Rating is the rated load-carrying capacity of an individual axle and wheel assembly. (It represents the load that may be steadily sustained by the components in the system; i.e., tires, rims, hubs, bearing, axles, brakes, suspension, sub frame, etc. with the GAWR limited by the components with the lowest working rating".

Tires alone may or may not increase a vehicles rear axle ratings.
Much depends on the rear axle type/brand/rating the chassis maker is using.
The axle manufacture may have a 18k rating but the chassis maker may use a lower 12k lb rear axle package.

And your chassis builder may have a uprate option with higher rated tires/wheels and suspension package.

Your rv manufacture and or the chassis mfg can help you there.

Legally the only way to increase any weight limit is for the work to be done by certified Upfitters. They can re-certify the vehicle for the new weight.

As far as a safety margins go; tires that will carry more weight will increase safety, possibility overload springs will help.

It depends on what the limiting factor is for the weight limit. If the tires are the limiting factor, then it is possible to carry more with higher rated tires.

Usually the tires are not the main or only limitation, though; it's some combination of the axle, the brakes, the suspension, the tires, the wheels, the overall vehicle frame strength, and possibly some other things I'm not thinking of at the moment. If it were as simple as using different tires, surely the manufacturers would put on the heavier-duty tires and advertise the larger carrying capacity (or, more likely, consume it with additional features and glitz).

You will increase the 'safety' margin but higher load rated tires (or springs, air bags etc) will NOT increase 'ratings'