Iridium Spark Plugs???

[roseytvr]

When I serviced the Griff last year I replaced like for like the B7ECS spark plugs which were originally fitted by the engine builder. Gone to replace them today and out come NGK Iridium BKR7EIX. WTF? The car did go back to the engine builder last year but he didn't charge me for new plugs and didn't tell me he had fitted them?

Any ideas on the benefit of these over the B7ECS plugs and why he would change plugs that were 8 weeks old when he had it? Not exactly on best terms with him at the moment so don't particularly want to ring and ask but I am curious as to why the swap and what I should put in it now, particularly as I have a new set of B7ECS ready to fit.

Thanks
Ian

[roseytvr]

Thanks guys,. the car went back with a suspected interference problem which as Gary says explains the change. The car has only done 300 miles since then so I will leave them in and see how they go. I have read the early thread blitz refers to ....... Oh dear! Lol
Cheers