What Plugs are used to replace Iridium Plugs

[Chippar]

My neighbour has an 2001 AUII XR6 which has done 112000k's and still has the original Iridium spark plugs. We've had a look at them and found that the gaps were all over the place and the tip coming out of the centre of the plug all varied in their lengths.

He has just serviced the car with new oil & filter together with a new air cleaner and is looking at changing the plugs owing to the visual condition of them.

He was getting fairly poor fuel consumption and he said that the motor seemed sluggish. We re-gapped the plugs to 1.3mm but apparently this made no difference.

As the Iridium Plugs are about $18 - $20 each to replace and out of the budget at the present time, which would be the best 'Standard' plugs to use in their place, if in fact they can be used, considering it is an XR6.