Payload versus sag

I don't have any spec straight out of the book, but look at the vehicle side on when its sitting on a flat surface.

Now unladen it will sit pretty level, get a couple of 20lt drums of water or 4 if you can, and now check the level, if it shows much of a rearward slope, I reckon you are due for new springs.

Keep adding a bit of weight at a time (or alll your camping gear) and you will soon see the rear drop.

Never really measured it, but I think you 'know' when your shocks and springs are fubar...

Load up the car, and then measure how much travel is left. Then think about how much weight is in there V how much travel in shocks is left V how much it went down when you loaded it.

EG if its 1000mm Unloaded, goes down to 350mm when loaded, its not lookin good, as you have used (650mm) more than 1/2 your travel before you have moved. First good bump its lookin like it would bottom out pretty quick.

If it bounces along like a trampoline, or bottoming out when loaded, they are stuffed.

Polyairs are a cheapy quick fix for the fully loaded car..

If you were lookin for an excuse to replace them, do it. Go a lift while ya at it...