Alloy wheels quandry !

[Happy Jack]

Hi,
Was settled on Supermetal hammer 16" alloys for my Ducato.
SWMBO said watch and wait for black friday or xmass or January sakes. Methinks that's fanciful but swmbo mbo.
They are rated at 1250Kgs per wheel = 2500 per axle.
Weighbridged in full hol trim at 1610 front, 1500 rear.
However, have today seen Fox Viper at £200 less for 4.
BUT, they are rated at 950Kgs each, 1900 per axle.
Still nicely above axle weight but Supermetal much better.
Super metal are made in UK. Fox, don't know.
Fox are gravity cast, would think Supermetal would be pressure cast to achieve density for the higher load rating.
Having looked at various websites can't find any more info except that there is a large range in both makes.
What would you do ?
Does anyone have any thoughts about what else I should be considering.
For example, I know I have to tell my insurer but would they need a TUV certificate ?
Anything else you can think of ?
Thanks.

 

[Guigsy]

Fox are gravity cast, would think Supermetal would be pressure cast to achieve density for the higher load rating.

The density of the metal is roughly the same as both methods just pour molten metal. The pressure is nothing like that from die casting, so it does little to compress and strengthen the metal. The difference is pressure casting can push the molten metal into more intricate shapes than just gravity casting. Pressure casting can make more structurally efficient shapes because you aren't so limited in mold shape, which is probably where some of the extra strength comes from. But it could just be a beefier design.