It does indeed - and to be honest the finished dish looks to have less oil content than many of the curries I cook using the old-school (thinner) base gravy recipes + a chef spoon of oil to fry off the g/g past, spices, etc in the curry pan.
I'm no good with figures (my maths teacher declared me 'figure blind'), but I'll have a go at working it all out. (Help and corrections welcome from any mathematically minded types out there!).
Thanks to differing quantities of oil in different bases, it's an inexact science, but, generally, in a standard portion of curry we use around 300ml of base, and in that base there will already be a certain amount of oil. Not a massive amount (some base recipes use more or less oil), but when added to the chef spoon (3tbsp) of oil that goes into the curry pan, let's say a total 4tbsp, or around 70ml ends up in the curry.
Now, the Glasgow curry base uses 2L (2000ml) of oil in total, and that's it. No more is added to the curry pan.
I'm not sure exactly how much in litres the Glasgow base recipe produces, but with 2L of water, 2L of oil and 7kg of onions, etc., it must be in the region of 8 litres?
So, 8000ml divided by 300ml gives us around 26 portions of curry.
2000ml of oil divided by 26 equals, near as dammit, 77ml.
Which means, of course, that the Glasgow curry base isn't significantly heavier in oil than curries produced using old school bases. (This is all assuming that the Glasgow base recipe does, in fact, produce 8L. If it's more, then we're obviously looking at less oil per dish.)
I've probably got this all horribly wrong, but if not then it's not too bad at all...