fuel consumption and other bits

i've just bought a 1982 W123 200T with no service history or any manuals etc. while i am familiarizing myself and getting hold of service manuals etc i thought i would just ask a few questions.
1. fuel consumption seems very bad, it has new tires, and spark plugs look good and clean, any ideas what might cause this? what consumption can i expect in town, and on motorway?
2. excessive white smoke on start up for about two minutes: i see from an earlier article this might be the head gasket going, is there a test i can perform to identify this?
3. does the engine have cambelts or chains, if belts i had better replace them.
thanks in advance for your help

1) What do you call bad fuel consumption?? 10mpg or 20mpg?
2) Normal
3) Chain
JackD

many thanks

that's great news re white smoke and chains, as for MPG, i haven't done a proper full tank test yet but appear to be doing about 10mpg which seems terrible for a untuned 2 litre engine.

my fuel consumption has dramatically improved due to the following:
1. i have just discovered my tyre gauge was broken, so tyres way too low.
2. i have developed a new style of driving. my other car is a sporty manual, and i was carrying over this baggage to the new car. i have discovered that the Merc doesn't like any of my driving input preferring just to roll along at it's own pace. so now i hardly touch the accelerator and it wafts along very happily. flooring it makes no difference at all.
3. my original assumption of comsumption was based partly on monetary value of fuel i was putting in. ie LRP which is more expensive than unleaded. i have since found out i can use unleaded so the cost has reduced too.
i might try one of these Hiclone things too in the near future.
thanks jb