Thanks for the quick feedback, gents.
Matthew, I know what you mean, I just wondered, as I did think that the GS430 would be more frugal than the LS400 (that was the previous motor) as it is more advanced an engine and carrying less weight. Not the case though. But I am no professor of energy and fuel.
That said, as long as its normal am more than happy, plus its good fun to hammer it now and then and see it go under 10mpg!
Once again, thanks for the info, and thanks Matthew for the carpet clips, very good of you.
Cheers,
Nick