LW Mk II fuel tank issue.

robertjp · 05-06-2014, 10:45 PM

Just wondering whether anyone has experienced this. When the DTE gauge registers approx 30Km's remaining the fuel tank accepts only 45lts. During the "Peace of mind service" I was told by the service manager that the tanks only hold about 80% of stated capacity!, has anyone else heard this.

robert.

RedChris · 06-06-2014, 08:45 AM

Can't recall exactly but pretty sure I've put more in than that. Also bear in mind that DTE will be conservative - there's more left in the tank than that.

robertjp · 06-06-2014, 12:09 PM

Yep, thanks for that, but how conservative is the DTE, will it account for 10lts, which is a lot left sloshing around.

RedChris · 10-06-2014, 01:22 PM

I'm due for a fill at the end of the week. If I remember I'll check what it takes. Certainly have not experienced this on other cars. My previous one if anything took slightly more than the stated capacity when close to dry.

robertjp · 10-06-2014, 03:29 PM

Thanks and can you also say what the DTE read, as I really dont want to break the fuel pump trying to find how much it will take.

**FoxtrotGolfXray 5.0** · 12-06-2014, 10:11 PM

My experience with the ST is that the DTE is extremely conservative.....overly so in my opinion.

I regularly run the DTE down to near zero and will only be able to put in around the 50l mark. That leaves me in excess of 100km to go after the DTE (and fuel gauge!) have reached zero.

Craig H

RedChris · 13-06-2014, 08:46 AM

OK filled last night, took 38 litres with 145 on DTE and a bit under 1/4 left on the gauge. So this sounds similar to your experience. Bear in mind DTE depends on how you drive. In my case it's mostly suburban commuting. If I was doing more freeway k's the DTE would be higher.

I would agree with Craig. The DTE looks very conservative.

robertjp · 15-06-2014, 12:11 AM

Thanks for that guys, am worried about running when DTE is 0, as dont want to ruin the fuel pump.

**FoxtrotGolfXray 5.0** · 15-06-2014, 12:43 PM

Quote:

Originally Posted by robertjp

Thanks for that guys, am worried about running when DTE is 0, as dont want to ruin the fuel pump.

Based on the experiences above, I wouldn't be too concerned.

To make sure, totally refill your tank as close to 0 DTE as you can. Note the number of litres of fuel you have put in, subtract that from the tank capacity (62l on ST IIRC), and you'll soon work out how much room to move you have.

And I wouldn't worry too much about the fuel pump, I have run beyond 0 DTE in my BA XR8, SY Territory, FG Falcon and now the St, and I have never had any pump issues in all those years (touch wood

)

Craig H

RedChris · 16-06-2014, 09:27 AM

From all I've read over the years the bigger issue is accumulation of muck at the bottom of the tank, which may then be drawn into the fuel system if you consistently run the car to very low fuel levels. In general the recommendation seems to be fill up once you get to about 1/4 tank.

Then again, if the Focus is very conservative in DTE/fuel level reading this probably won't be an issue unless you push your luck by running on 0 regularly.

**FoxtrotGolfXray 5.0** · 16-06-2014, 03:47 PM

Quote:

Originally Posted by RedChris

From all I've read over the years the bigger issue is accumulation of muck at the bottom of the tank, which may then be drawn into the fuel system if you consistently run the car to very low fuel levels. In general the recommendation seems to be fill up once you get to about 1/4 tank.

Then again, if the Focus is very conservative in DTE/fuel level reading this probably won't be an issue unless you push your luck by running on 0 regularly.

Yeah, old wives tale, I reckon. Think about it, anything that is too heavy to float will sit at the bottom of the tank. And where is the tank pickup? At the bottom of course! And I wouldn't be worried about anything that is floating.

Anyway, again, in all the years I've been doing this, I have never had a problem, either with the pump or a fuel filter getting blocked.

As soon as I got the ST I realized that the DTE was conservative, and I have run it down to 0 DTE regularly (as in at least once a fortnight) since, without a hiccup. So that's been nearly 11 months.

But at the end of the day, it's your car and therefore your call.

Craig H

LordFordNZ · 16-06-2014, 04:39 PM

Doesn't the fuel act as a coolant for the pump?..so running it low will make it run hotter and possibly fail earlier?

dan- · 21-07-2014, 03:02 PM

i have managed to put 48L in my LW focus.... i was beyond 0 on the DTE readout though. most cars leave a safety margin, the 0 is not really 0.

SMP · 22-07-2014, 12:10 AM

Hi all!
Most automobile fuel gauges are inaccurate. Think of it (over-simplifying it a bit) as based on a float in the tank. As the tank is almost full, the float is already at the top and cannot rise higher. So the fuel reading stays at or near the full mark till the fuel is sufficiently less than full.
Similarly, when near empty, the float is already resting at the bottom so the car cannot accurately tell exactly when it will run out of fuel.
Of course, this is from a while ago (I studied this in engineering about 15 years ago) and I don't know if measurements systems in family cars have advanced a great deal since.

You can read a more detailed explanation here - http://auto.howstuffworks.com/fuel-gauge.htm

As for my own experience in my LW MkII Focus, there's about 5 litres left in the car when the DTE goes to 0. You can keep running it (economically) for about 50-60 kms but I wouldn't go much further than that.

Cheers.