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Discussion Starter · #1 ·
Hey guys I've been obsessed with the RS for a little over 5 years and I know this is only the greeting section but have a few problems and wanted to see if anyone could message me a fix or possible resolution as I've take my car into ford 3 times and they said they don't know what the problem is or that the computer says something when the digital dial shows otherwise.

So back in January I went to fill my car up and the gauge showed 330 miles till empty. This shocked me because from Feb 2011 till Jan 2015 it used to show 440. I put in the fuel system cleaner and it didn't help, I watched my speed in town and didn't help. The gauge estimates 22-24 mpg. Even when I hit reset that gauge used to spike to 40-60mpg then slowly lower to the 30-35 mpg range but now it doesn't.
When I took it to ford dealership they said its probably a broken fuel system but they checked that twice and said it wasn't the issue the computer told them I was avg 35.9mpg. I then asked if that's the case why does the digital estimate show me at 21.4 mpg on this tank and their response was I dunno. After hundreds of dollars spent on a computer update, tune up, new tires, fuel changes, I'm still no closer to getting back to the normal mpg I once had. In Fact this last week filled it up and only got to 287 miles till empty. HELP if anything can be suggested. I searched online and my model the gas tank says the fuel filter is built in and only replaced with entire tank.
 

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Hi,

Is your car standard?

Did you first notice the problem after you modified something (like a new fuel pump) or did it just start playing up?

What is the actual mpg you're achieving? By actual I don't mean what is says on screen. What you actually achieve.
 

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If you disconnect the battery it will go back to factory settings then you can start again the car will take in to consideration your driving pattern and how many miles you get to the gallon.. and should give you a true reading then....

I get 435 in mine now and I am showing 33.1 to the gallon..or what ever it is showing

I had some work done about a year ago and they disconnected the battery and I lost 100 miles in the fill up stage but it soon came back to normal

Just my opinion of course :smile:

And Welcome!
 

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Discussion Starter · #10 ·
Nothing has been altered or modified. It is automatic. I would have thought during all the work they would have unhooked the battery but I'll definitely try that first thing tomorrow. I appreciate the prompt responses. Looking forward to trading it in for the Focus RS in 2016.
Do all mk I and mk II have the 5 cylinder? I watched an episode of Jay Leno's Garage and it showed a 2010 that had a after market custom exhaust and header and was pushing 420 bhp.
 

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Discussion Starter · #11 ·
I'm achieving 290 miles per tank. 24 mpg.
No caravan. I'm not part of the formally known as top gear staff. ;P
 

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There are so many factors that can alter fuel economy. Here are a few
Tyres. Make sure they at correct pressure. Check there ratings etc. a bad tyre can cause poor fuel economy
Do you have a roof rack?
Do you drive with your window open
Do you drive with the air con on
Do you have a boot full of old toot. Luggage or old bits and pieces = weight and ups fuel use age
When did you last have a full service. Old spark plugs. And old air filter can cause this
Have you had a live data on the lambda probes
Is there a hole in your exhaust

There are so so many factors and can bore people. But there are a few factors :)
 

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If you're actually achieving 24mpg on a standard non RS focus something is a miss for sure and it isn't the computer because that mpg is far too low. I assume you calculated that manually.

Did you check it for error codes?

The mk2 is a 5 cylinder. Many of us push more than 400bhp, the engine is capable of more but should be forged. The mk1 is a 4 cylinder engine.
 
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