I've already replaced the cap and gasket - someone else mentioned that as well.

I will be going to a higher viscosity oil next time around - had I known about it then I would have had it done this time. I also added a can of an oil additive which said that it would reduce oil consumption - whether tis true or not I don't know, but I just checked the level yesterday after almost 700 miles and it was still full as per the dipstick. Maybe the combination of the two (new cap/gasket and the additive) did the trick.

Someone else suggested the Valvoline "old engine" oil. Is that worth a try? The only experience that I've had with synthetic is with my old '77 VW rabbit - I tried some not long after I bought it in '78 and it went right through the car. Most expensive oil change I ever had. Went right back to Castrol 20-50 and had no trouble.

Sean