normal,absolutely normal.i have a ug2 180.its 36k young now,everytime from the begening its drinking oil.no engine prob till now.used my bike for one of the most toughest terrins of sikkim for first 20k kms,no smoke just less oil while draining.but i noticed some points,,,,

i was using castrol power one and penzol at the beginning,used gtx also,yes didnt knew about oil much back then!!the drop was big 100-200ml.
then shifted to castrol gtx magnatec for few time,evaporation was less.

now days on motul-much much less(5100).
did a trip of 3.5 k kms including a 2 nonstop 490kms runs with valvoline premium 4t.the oil consumption was less then 100 ml only.

nowdays i use 1.1 lit of engine oil.doin this for last 10 k kms.tip top.my pulsy never ran so smooth.motul rocks...

these are only my experiance.not to offend anyone,but my friends new p220 seems to drink less and lees oil on long trips,may be the oil cooler helps..

and yes when i used car engine oil at the beginning ,no clutch slip or prob was there,never.

^^^ I am going to use Motul 5100 next time. The Valvoline seems tobe highly biased to evaporation.

The Doc meant Valvoline is better because it evaporates less. It is one of the very few 20W50 oils available in the market. It suits perfectly. I have found it to be better than Power1 on my P180UG3

May be. But, I am using Valvoline from the past 10000kms, it is good, but definitely needs probably some more engineering to match 5100, I have used 5100 too, but due to leaky nature of my bike I switched to Valvoline. But, for highway rides one needs to put all new oil again. I mean to say that if you are doing a new trip of approx 1500kms, no matter if the oil used is only 1000 or even 500kms old, change it to new. And as Drvmtm said, for each tour pour in extra 50-100ml so that it could equal the loss caused by evaporation. This is very good point raised by doc and I am gonna try this everytime now.

It could well be that this is due to the fact that many engines use more oil when they are new, during the running in period. Then oil consumption settles down until the engine tolerances increase through wear, and the engine starts burning more oil again.

The oil cooler cools things down, but I would say it is there because it was needed in the first place. The oil temperature on both bikes should be about the same for proper lubrication. Some engines run hotter than others, and might need an oil cooler to bring the oil temperature back down to normal. Also some engines that don't have one may benefit from having one fitted later. And I would have a guess that air-cooled engines driven in hotter climates like in Chennai would be good candidates...

1) Refer the manual for the exact procedure to check the level.

2) Reboring will only increase the bore slightly while the oil is poured into the crank - so that shouldn't require more oil.

3) Reboring will not effect the oil level reading one bit, cause of the same reason, the reboring increases the bore size whereas the oil is poured into the crank/engine. You can remove the head and bore with the oil still in the engine so.... I hope I was able to put my point across.