Wonder if any one can help or advise me.

I'm noticed occasionally black smoke/soot coming from My focus convertible, While starting up from cold. Also their seems to be an oil loss but has no signs of leakage.

Fuel consumption seems to be down also. Normally I achieve 42 to 50 mpg but currently over the last week can't get any better that 30 mpg.

My car is a 2 litre Duratec Petrol. 60,000 miles since manufacture 2008.

You're burning oil is the simple answer why is another could be worn piston rings or the oil cooler is leaking into the coolant which would be evident by a film of oil in the expansion tank 50mpg from a 2.0 petrols optimistic mate to be honest the real world mpg isn't that high

Rings or valve stem oil seal maybe

get a compression test done

If your burning oil I'd expect it to be blue smoke not black, black smoke is unburnt fuel. Sounds to me like it's running rich on fuel and might explain the drop in your mpg. As for it using oil, has it noticeably increased recently?

42 to 50 mpg on 2 litre petrol! I struggle to get 35 on my 1.6 :)

I do belive i was a bit rich with the MPG figure. Real world it was between 36-40.

I had a problem before with the throttle control body and EGR valve which was repaired 2 months ago. Oil lost at the time of changing these bits at awards was ok and didn't use any from then. But when these components did fail, oil loss was occurring. Approximately was loosing 0.5 L in every 500 miles I did.

Afterwards*

At current I'm adding around 0.5 L every week.

I was under impression blue smoke was oil burning

Black smoke is probably from the rich fuel mixture. I'm under the impression that petrol engines can emit black smoke the same as a diesel (I've never seen black smoke on a petrol).

Oil burning will emit blue or grey smoke.

At current I'm adding around 0.5 L every week.

What sort of mileage are you doing per week?

100 to 120 miles

Seems obsessive u know but has no signs of a leak anyware.

That's a lot of oil for that little mileage, I'll do some digging.