my neighbour who had been having low MPG out of his 1.8 VVT, is now a happy man, after I fitted a set of BOSCH SUPER in his motor as the gaps in his GM plugs were all over the place (same as mine) he did a 523 mile trip 99% Mway he went over night and sat at 70 every where he could, the car used 57.4 ltrs, so 41.44 mpg,( he got 34 on his last trip there) and going up to scotland the car was very heavy, so not to bad then, BUT I still can not work out why the GAPS go out so far in the GM plugs, my plugs had aprox12,000 and his 20,000,