Excessive fuel consumption

[Joec26]

Hi. We feel that our 2003 MX 5 1.8 has got very hard on petrol. It was never economical but it seems to have disimproved, despite it being serviced regularly and having a 6 speed gearbox. Would it be the spark plugs or does the air filter get dirty quickly. A recent drive of 150 miles used 3/4 of a tank. Must do a proper reading soon, but any ideas? Also, is there any Mazda or MX5 specialist (or someone with special knowledge of MX 5's) in the Midlands? We are in Mullingar. Thanks, Joe

[Steve]

worth changing your spark plugs, ignition wires and air filter if not done recently.
Also check and see if you have a dragging brake/sticking caliper (most likely rear).

[Joec26]

Will do thanks. Calipers already replaced as an nct failure item last time. Could be faulty again of course! Do you think plug leads could cause it? Are they a common problem on MX 5's?

[Steve]

Not an issue really more like a consumable MX5's tend to need them renewed every 30-40k or so.

[93 Mk1]

As mentioned, try the air filter. Do you have an induction kit or the standard type panel filter ?
A clogged or partially clogged filter can cause this.
However, it might be worth checking through the diagnostic port to see what error codes appear.
A defective sensor somewhere might show up which could have a detrimental effect on your
fuel consumption.
With the ever increasing prices of fuel you certainly get alot less fuel mileage these days !!!!