burning oil

[Decsi Miklos <MDecsi@pgsm.hu>]

Hi,

 my '83 80q eats about 1.5-2 litres of oil in 1000 km. There isn't any smoke
comeing out, except one case: Speed is around 150 kph, when I step off the
accelarator as the engine brakes tha car reeeally big smoke coming out of
the exhaust. Except for this, absolutelly no smoke.

 Engine runs well, compression was checked 1 moth ago and it is excellent.

 What could be the problem?

DM

Ps: What does the little yellow arrow means on the center of my dash?