Your friends are probably talking about old technology engines running "heavy" oils with viscosity 20W-50.
All modern engines run very thin oils, typically 5W-30 and have low compression pistons to reduce internal engine drag and therefore improve fuel consumption and increase power outputs.
So all modern engines will consume oil. After all, how does an engine lubricate the piston rings and not have some oil burnt up in the combustion chambers?
Another side effect of "thin" oils is that there is more chance for the oil to end up as blow-by vapour. So the hot oil mist from the engine gets sucked up by the crankcase vent into the intake manifold and is combusted by the engine. The thinner the oil, the more oil vapour will be present in a fully warmed up engine. That's just to be expected. Toyota has gone to a lot of trouble to minimize the amount of oil that is burnt off as vapour through the oil separator design:
http://intranet.toyotaperu.com.pe/tdp_sit/data/LEXUS/LX/rm2450e/ncf/pdf/nm08g5e/m_nf_0065.pdf
However, some vapour will still get past the oil separator.
The question is how much oil consumption is considered normal? In the case of modern engines, you can expect far higher engine oil consumption compared to older engines. That's just a fact of modern engines.
If your engine consumes 1 litre of oil for every 5000 kms, I would expect that to be normal. Check your owners manual for the specifics.
