I find the C3 1.4 SX was gutless and the economy was average, but now at 4,458 miles it seems to have improved but nothing like the figures they push in the ads'. Also on occasion I chuck in some Red-X to help keep the injectors clean, can't do any harm.
On reflection though, I'm probably not a good example of economy, my car already has a weird drive problem that is not obvious to the eye. I honestly think that a ring gasket that allows the exhaust to move when accelerating may be missing at the flexible exhaust joint, the one with the spring bolts. I've looked and it does not seem to have one, only a rounded end to the CAT down pipe, which slots into the mid section tight enough to make an adequate seal, but unfortunately allows no movement at the joint.
To improve the drive quality and acceleration, I have to keep greasing this joint, but it only lasts for a week. That won't help the situation as without that ring the exhaust will always act as a brace through the centre of the vehicle. I've found a lot of manufactured cars are sometimes built without this in place for some reason, which is fine until the joint cokes up or rusts' then the joint becomes rigid and restricts the engine from turning like it should, causing vibration and strange acceleration, handling and clutch action. i.e.: sometimes picks up fast and then sometimes sluggish and judders with engine rev vibration.
Does anyone know if there should be a loose ring gasket that sits between these two exhaust parts, and which way the spring bolts should face on a C3? Should it be springs facing forward to the engine, or springs facing backwards to the rear of the car? I know the Saxo is springs forward, but my spring bolts are facing backwards??? I feel I will still need to get an exhaust ring to hopefully sort this problem, Citroen dealer probably thinks I'm mad, but they cannot be bothered looking to see that there's not one in place, obviously not a concern to them with it being a new car.
For a few quid and 10 minutes, I'll do it myself.