Circa 13mpg, yet your emissions are OK?

sure it's not just trickling out of a hole somewhere?

Just a thought but are you 100% that the new cam sensor is working? Try disconnecting it to see if there is a difference. I have heard that some aftermarket sensors are poor quality.

+1 the aftermarket ones have a very bad rep vs OEM

the price between an oem and after market was on £8 so i went for an oem.

Today on my drive into work i averaged 22.8 and the range went from 29 from leave the house, to 27 to work, as i do work only around 2 miles from home and i drove the same way as i always do at that time in the morning, steady flow. but yesterday, driving home again the range was ticking down 2-3 miles a minute and mpg when i got home the average was 13! the only variable being the today is wednesday and the air temp!

Sounds like your journeys to and from work are on constant cold start cycles, doing only 2 miles.
That won't be helping your average fuel consumption one little bit.

Intresting to see what brim to brim figures will reveal - i doubt there will be any huge differences from previous calculations. Brim to brim is if you want nth degree mpg figures .I always fill up beyond warning light and simply divide gallons by miles travelled and to the button the mpg is always always consistent.

Well, the results are in from my, empty tank, full tank, empty tank trial.

But first, I’d like to respond to some of the comments added lately, not all my journeys are around 2 miles and its virtually impossible not turn the engine off until you’ve got a good few miles and temp under your belt, but from occasion I will only go from the house to the office and back. I do a few fair miles each day and obviously drive the car in the morning, afternoon and evening.

Secondly, its defiantly not the ODBC, as it does indicate the correct Range and I am confident the correct MPG too. I am sure of this since having ran out of fuel on two previous occasions the range figures have descended to the ‘- - -’ marks then within a few minutes the engine has juddered and conked out! Also, refills are far too common and full tanks have gone into the 60 odd litre mark so the ODBC is in my opinion accurate enough.

Thirdly, I’ve noticed the warm weather has made a positive difference to performance initially, from start up its more prompt, less laboured as though its gained an extra 20 odd Nm of torque! But within a few miles or so the performance drop returns, so I am assuming the coolant temperature sensor may also be at fault. Anew one is ready to be picked later tonight for £22.

Now then, the empty tank test. I tried to carry out the test as scientifically as possible;
- Ran until completely empty (conked out first time at the car wash so got the lads to push me to the service station! second time 2ft from my drive way and got towed to the service station by my dad’s cab – thanks dad!)
- No extra weight which meant no passengers or extra bags etc
- Consistent fuel supply, Shell unleaded (now at £132.9p happy days!)
- Drove like a saint
- Kept tyre pressure at 32 and 38psi as recommended (although it obviously fluctuated during the day)
- And kept air con off no matter what

The result from empty to full to empty to full, was on average ***16.3MPG*** including around 20 miles of motorway driving and I managed to squeeze in just shy of 65 litres (64.1 and 646) each time.

So now the plan is to swap the coolant temp sensor, test and then eventually fit the O2 sensors which will need more time and effort so jubilee weekend!

Any ideas or points on the above?

Yep, dead on 12 o'clock!
OK, will look into the air temp after the coolant, any ideas where the air temp sensor goes?

isnt that the coolant temp sensor?