Over the last 2yrs my 03 1.9tdi octavia has been slowly getting less mpg. I used to get between 55 & 65 mpg on my drive to work. Now I get between 40 & 55 mpg on the same drive. Can any one guide me as to what to test for.

Recently the engine un-noticed over heated and worped the head caused by a knackered cooling Fan and tthermostat. So have had the head reconditioned along with the turbo and the injector s cleaned & tested and have disconnected the egr valve.

What next?

I'd check cam timing to make sure it is correct use the locking tools to make 100% sure it's correct as well

Hope this helps

Serviced properly? Tyres pumped up right? Could be tons of reasons why

Same time of year? Same fuel?  When was the car last serviced?  Have you been on an all you can eat trip to a pie shop?  Tyre pressures correct?

 

Binding brakes, blocked airfilter, dodgy MAF, CTS, sticky vanes, boost leak, timing out.

 

So many possible options, I think you need to start by getting the car scanned for faults first and then take it from there, if the servicing, etc is all up to date.

Hi, thanks for your replies a bit more info.

it has been serviced annually by skoda last time had all new filters with addition of extra oil change every 6 month's. Tracking and wheel alignment all good tyre pressures all as per specs. Timing is correct, no vacuum leaks or obvious fuel leaks

It drives and performs well with no black smoke on acceleration.

Have you started buying cheaper fuel, like supermarket stuff? Or changed the tires for different brand or type? 

So the car still feel as nippy as it used to?  are you getting caught up in more stop/start traffic (not sure what your journey to work is like)?

Do you know which 1.9 engine it is? 90/110bhp or a pd130?

Had it checked out, or rather had fault diag run and the maf sensor amung others faults detected. New maf fitted now even more poke and a little more mpg but still not what I used to get. Going to give it a tank of fuel and work it out

Drive to work is the same takes around 15mins. As for fuel was using shell now using esso thanks to works fuel card.

Gonna get it fault diagnosed again soon to see what else is not working properly!

More updates as and when.

Any extra help is much appreciated.

Had it checked out, or rather had fault diag run and the maf sensor amung others faults detected. New maf fitted now even more poke and a little more mpg but still not what I used to get. Going to give it a tank of fuel and work it out

Drive to work is the same takes around 15mins. As for fuel was using shell now using esso thanks to works fuel card.

Gonna get it fault diagnosed again soon to see what else is not working properly!

More updates as and when.

Any extra help is much appreciated.

Must be the fuel mate I personally think esso is **** shell all the way