First off they are illegal on road - not that you are likely to get stopped
.
probably would blow your fuses  more important the extra heat generated may
cook your wiring and or headlamp reflectors if they are the plastic variety.
If you want more light output get some premium xenon halogen units the
difference is well worth the money and they just fit the standard fittings
and dont produce any more heat or load .Ebay shops sell them quite cheap I
bought  Phillips from Halfrauds when they were on special but there are
plenty out there
Derek