Found this about the difference for fuse rating, may be of some interest for all but mostly for the US guys as you will the way fuses ( I believe it's more centralize now) are different. I also made a chart to keep in my driver's manual if you wish to print it.

Drooartz: British vs American Fuses

 

I wonder what years this applies to? The modern Jags use AGC fuses.

 

I'm 99.99% sure it applies only to the old glass fuses


Cheers
DD

 

guess I did forget to mention that, yes the glass ones

 

Ah, thanks. I no longer have any British cars of that vintage sad to say.

 

All glass fuses come in 2 types fast blow and slow blow.

Fast blow will fuse with its rated current and have little tolerance for surge current.

Slow blow will tolerate surge currents up to 10 times their rating for very short periods, such as inrush current from turning on inductive loads.

Slow blow fuses have some sort of coiled interior visible where as fast blow usually have a single wire.

 

My understanding is that the USA rating system is the maximum amperage the fuse will hold continuously. The British rating system tells us the amperage at which the fuse will blow *instantly*.

Perhaps we're saying the same thing, differently?





These are dual element glass fuses such a MDQ, MDL, MDA, and GDL. I don't think I've seen dual element fuses in automotive applications. But every day I see something new, it seems!

Cheers
DD