Does this make it the "Incredible Hulk" of oil additives? Does it turn green and burst out of it's shirt when it's angry? Sorry, just my warped sense of humour there! Seriously though, there's a lot of devices on the market that claim to improve fuel economy my placing a magnetic field around the fuel line and hence polarising the fuel molecules, in effect ionising them. If the theory is right then itr could well be STP does a good job.
As for Penrite oil, i've not seen it in this country but i suspect these guys might have something similar :
http://www.smithandallan.com/
Some of their prices seem a little steep but on the whole they are very good on price - 5L of WD40 for £9 and 5L of 20W50 for £9.30. Granted there is shipping on top but you have to drive to the motor factors to buy your oil which these days with the cost of petrol is probably more!
Cheers,
Dave
