Poor fuel economy

[Matteh]

Think this is the right sub forum to post in

I came back from uni today ~ 220 miles. i sat at about 75-80mph most of the way (few sections of roadworks).

however, this took an entire tank of petrol! the light came on just as i got home! normally it takes just over half.

Before i left, i topped up the coolant but i think i might've filled it up too much. the temp guage was at ~ 0 the whole journey (temp guage normally works). Am i right in thinking that this would cause the engine to be running with the choke on, thinking it was cold.

i hope so, otherwise what else could be causing such bad economy!

car is a mk1 1.8 8v btw.

 

[drsmith]

sounds like the coolant temp sensor wasnt reading the coolant temp, therefore yeah it can keep it on full choke. did your heaters work on hot? if not then it could possibly a water pump issue, or fingers crossed it could just be too much coolant and a very efficient rad and fan not letting it warm up! also check your air filter

 

[Matteh]

air filter is new (well, 5 months now) as is the rad/fan

heater is broke radweld = blocked heater matrix.

normally the temp guage is fine, getting up to about half, sometimes 3/4 when the coolant is getting low.

was just wondering if the whole choke thing sounded reasonable.

 

[yames]

sounds like the thermostat is stuck on open, shouldnet cost to much to fit a new one depending on wever u do it or u get a garge to.