I've had my focus since last August. It's been a reliable runner since hitting 41Mpg when I first got the car on average. The only thing that I've had to replace is the poorly designed heater matrix rubbers leaking into the drivers side foot well and had the ECU updated and throttle body cleaned to cure the cut-out when you pull up at lights.

I've noticed over the past few weeks the mpg has plummeted and its now averaging only 28 mpg. All the tyres are at 30psi and I don't believe my brakes are binding, it isn't overheating at all.  Its not using any oil, starts first time and runs on all 4. I've tried bottles of redex and that might up it to 30mpg but its still pretty poor for a 1.6 engine isn't it??

I can't say it feels like its got 125 bhp because its so long geared and I was used to a Passat TDI before it, so the things dog slow at the best of times, but I wondered if anyone on here has any ideas?

 

Update:  (if anyone is listening on here)

Still getting 28mpg, but just passed the MOT. Flew through, no advisories, nothing.

Have you filled it up before testing mpg?

Here is some related chat on the same engine 

 

I have the 105 version but the quoted mpg is the same. Coming from a diesel has been an adjustment  but I average 49/51mpg on my commute to work, 30 miles each way with a 50/50 mix of motorway/DC and A/B roads. Highest I've got was 58mpg but that was just after I filled up and mostly on motorway. I think the quoted 60mpg for motorway is achievable (for me at least) on a longer journey, I will be testing that in may as I'm travelling up to Cumbria. However, I am a lorry driver so my style of driving will probably be very different to yours. I have noticed on shorter journeys it will drop but I haven't got less than 48 so far so from my perspective yours seems low. Six months after I got my last car (2010 diesel kia ceed) I had a problem with  rough idling and smoking on start up combined with a drop in mpg. Turned out the car had never been serviced before I collected it and the mechanic I took it to suspected the fuel filter had not been changed for years if ever. Once that was all done things improved greatly. 

Can't comment from personal experience of this engine, unfortunately, but a few general thoughts.

If you have experienced a sudden drop in consumption something must have changed.

A normally aspirated petrol is always going to seem a bit "weedy" after a TDI but has it always seemed down on power or only from around the time of the mpg drop?

You mention it not overheating but is it warming up ok? If not could be a thermostat issue.

Has the pattern of use changed, e.g. more short journeys, frequent cold starts etc?

Has the weather caused increased use of heater blower, heated screens/mirrors etc?

As I always say on these threads, my old 1.6 99bhp Focus achieved about the same sort of MPG in winter. Not sure anything is wrong really, Nat Asp petrols are always quite thirsty as they need to be worked harder.

buy a 2.0 tdci. i get 45 rpund town and 61 on a run

Finally resolved the issue this week. All along it was a faulty battery. I had no problems starting the car ever, no fault codes or dash lights at all, just pitiful power and terrible MPG for years on end. I just thought the car was meant to be like that and didn't pull me out of bed.

Today, my battery light came on. Turns out the battery was only charging to 45%. A new battery later, its like a new car, pulls in every gear and is getting 35MPG around town. Honestly, a poor spark was the issue due to it pulling the juice from the alternator constantly. I suspect its having to relearn the fuel trims, but so far its made a massive night and day improvement.

28 minutes ago, Buggerlugz said:

Finally resolved the issue this week. All along it was a faulty battery...

 

In over 40 years of motoring, I would never have associated a faulty battery with poor MPG, every days a school day!

Me neither Stephen!

3 hours ago, Buggerlugz said:

Finally resolved the issue this week.

That's good to hear and thanks for coming back after all this time. A lot of threads turn out like unfinished novels!