Out of curiosity, how much fuel does the engine use to idle (the computer should be able to tell you in gallons or litres/hour). Warmed up, a/c off, should be no more than 0.25gallons/hour-at the very most. It is very difficult to reject a car for poor fuel economy alone. But there is always a reason behind it-and you can reject the car if the dealer can't rectify it.

Thanks for your reply.

The car runs perfectly and up to expectations in every way apart from the MPG.

On a run (100) miles it does 39 mpg, If I reset the trip on a 6 mile local run when the engine is warm it acheives 32

Out of the entire 900 miles and per tank it's average is 25. The Car is never left running whilst waiting and not used during peak times when you would expect to get stuck in traffic.

Maybe also check the tyre pressures - and blow them up as hard as VX say for the "EDO" or loaded pressures - at the expense of ride comfort of course. Little things will not be the solution but it all helps.

This car also has a turbo - start using it and mpg will plummet.

No it doesn't.

The 100PS is the same old junk from the Corsa with VVT slapped on. It's AVAILABLE with a turbo, which has 138hp, which is just about adequate for the lump of lard that is the Mk6 Astra.

It's also totally unsuitable for a car the size of the Mk6 Astra, I had one as a rental and it was dire. Almost dangerous it was so slow. Couldn't even pass a truck on a climbing lane on the A628 between Manchester and Sheffield. We only got mid 20's mpg.

OP, I don't know what you expect - you bought a 1500kg car with a lawnmower engine, you're not going to get decent MPG unless you constantly drive down hill.

Erm, as an Ex 110BHP Galaxy driver & now in a 105BHP Octavia, I have never felt underpowered, the Octavia in particular I feel is plently powerful for general driving & 70mph plus Motorway work.

Anyway a modern 1.4 litre petrol engine should be well fit for an Astra sized car.

But, but, but its all under the control of the right foot, both performance & economy.

I am guessing you drive a diesel. We had a 108 bhp Focus TDCi, great car, plenty of power, very good economy. When we bought it we also tried the petrol version, first a 115 bhp 1.6 and it was dreadful then a 122 bhp 1.8 and it was little better. The diesels are turbo cars and give better low down power than petrols which feel very lacklustre on the road. OK, the petrol would probably leave the diesel in the traffic light grand prix and on top speed but in the big world its performance between 30 and 70 that really matters.

Personally I would expect a 1.4 non turbo in a modern heavy car like an Astra to be very underpowered, not driven one but after my experience in the 1.6 Focus I have no desire to.