Originally Posted by SafeChav
Because the relays in MFi cars and alike firstly are very primitive and poorly made, but not only that they are all very under-rated. I dont think theres a MK3/4 on the planet that hasnt melted its relay, as soon as the pump gets a bit old and starts drawing a little more current they just burn out. They are rated 16A which is BORDER LINE for requirements.
The relay on an EFI car is rated at 30A, so there is A LOT less chance of failure/fire
The tachometric relays are more advanced than the later relays, hence 'tachometric'. I fuel pump should only draw 4 amps, so a 16 amp rating is not a problem. If your pump starts drawing more than 10 amps your pump is the problem, not the relay.
