Without being flippant, what does than mean in real terms? The car I was buying the expensive oil for (about £40) was a Smart For Two, compared to other 5/30W which was about £30 which was specified for a Honda CRV and I also used (as specified) in my MX5 (1.8i), both of which I would think were more demanding engines in terms of performance. As it happens, I used the more expensive oil, an extra £10 / year is peanuts - I was just curious. I suppose, as much as anything, I'm wondering if the oil is really that more expensive to make or just sold at an inflated price as it is labeled for Mercs/BMWs etc.