So I was chatting to a colleague at work about how I managed to get over 500 miles in my VRs before refueling, and he claims that you shouldn't let the fuel level drop that low as there's all sorts of sediment etc... collected at the bottom of the fuel tank which isn't particularly good for the engine - i.e. you should refuel as soon as the fuel gauge light lights up. Is there any truth to this? :confused:

He was driving a Golf PDI130 as well, so same engine...

Cheers chaps.

yes you will find sediment in the bottom of a tank as your colleague said its best not to run it to low as it may cause damage to pumps, filters and injectors.

hope this helps

yes you will find sediment in the bottom of a tank as your colleague said its best not to run it to low as it may cause damage to pumps, filters and injectors.

Thats why there is a fuel filter fitted to the car...

some folkes i know say this as well, i re fuel when i get to 30 miles left in tank but then once filled up i give it a boot and let some cr@p out the engine. because if it is true then best time to get rid of this crud in the tamk would be when its floating around after fueling, but i do also use the millers 4 sport to help clean it all out .

Thats why there is a fuel filter fitted to the car...

it doesnt get all of the sediment

Right , here's a number of things wrong with the theory about never running a tank very low.

Firstly , you have a fuel filter so anything too large to go through the injectors and into the cylinders will be caught there.

Secondly , there simply isn't that much crud in fuel anyway - refineries deliver good clean diesel so if there's any contamination it will be from the tanks at the garage and then you'll have a whole tankful of it.

Thirdly , if you usually run the tank down to the bottom there isn't much left from the previous load and that all gets diluted with the next tankful so it isn't like there's a pool of mud at the bottom waiting to be sucked through.

Finally , where do you think the fuel line is connected to the tank?

It's at the bottom so the fuel drawn through the system is the stuff that's lowest in the tank , so even if there is slightly more crud that's settled towards the bottom it gets used first

it doesnt get all of the sediment

surely if what the filter doesn't get was bad for the engine then the manufacturers would develop a more effective filter!!!

Old wives tale.

used to be true on older cars doesnt apply much anymore.

In the days of cars with painted metal fuel tanks, the paint used to flake off eventually, and sink to the bottom of the tank. The Fabia's tank is unpainted plastic.

Quite a few taxi driver's I used to know fell foul of using a certain fuel station. They were not as scrupulous as they should have been regarding cleaning of tanks etc and water from condensation had built up. Result - a lot of stranded taxi drivers.

I Ran mine for three years at about 500+ miles a working week and always ran the tank from brimmed full to empty, never had a problem, of course it was always serviced regularly though.

Quite a few taxi driver's I used to know fell foul of using a certain fuel station. They were not as scrupulous as they should have been regarding cleaning of tanks etc and water from condensation had built up. Result - a lot of stranded taxi drivers.

As I said , if you get contaminated fuel , you'll have a whole tankful so it doesn't matter how full or empty it was at the time.

poppycock! I let mine run down as close to 0 as possible, sometimes ON 0 - Usually when the buzzer goes off I run through the plans for the next couple of days and think where's best to fill up. Not had any sediment issues in 100k+

Finally , where do you think the fuel line is connected to the tank?

It's at the bottom so the fuel drawn through the system is the stuff that's lowest in the tank , so even if there is slightly more crud that's settled towards the bottom it gets used first

All the fuel tanks I have ever seen have had the outlet at the top of the tank with the fuel outlet/return supplied by pipes that go into the void of the tank but dont go all the way to the bottom so not to pickup sediments

The outlet pipe attaches to the top of the fuel pump (pickup pump in the case of a diesel). This pump then gets its fuel from near the bottom of the tank.

The engine does not suck the fuel out of the tank, it is pumped by the fuel pump which takes it from as near as dammit to the bottom of the tank to give maximum range. If it took it from any higher then the engine would be stalling with a quarter of a tank still sat there!

The fuel filter does a damn good job of taking out particulates from the fuel too.

Water is one of the only things I'd say it would struggle with. As water is heavier than oil it would sink and so be picked up first by the fuel pump. If the diesel was heavily contaminated I'd imagine the car would stall quite quickly as the engine would be receiving nothing but water as the lower part of the fuel pump would be immersed in it.

i've run mine many times to very low miles remaining , even zero a few times , when i changed my fuel filter at 40k , i totally drained the filter of the fuel , just to check what , if anything was collected in it , got to say , absolutely nothing came out , that includes the water drain at the bottom

the same couldn't be said for the filters we check on some Fords , not only are they full of 5h1te , but also metallic particles from the fuel pump, these are even visible on the latest Focus 2.0 TDCI

In the days of cars with painted metal fuel tanks, the paint used to flake off eventually, and sink to the bottom of the tank. The Fabia's tank is unpainted plastic.

Yes, i had this on an old Renault 9 AND a Renault 21. The paint on the inside of the fuel tank flaked off, it used to run terribly every morning until it had cleared it all out!

I think that people are thinking about this too much. When you tank's empty or it's convenient - fill it up.

Inevitably, with all the cars on the road, some will end up with clogged injectors. The vast, vast majority won't. You really don't see that many broken down cars, especially these days.

the same couldn't be said for the filters we check on some Fords , not only are they full of 5h1te , but also metallic particles from the fuel pump, these are even visible on the latest Focus 2.0 TDCI

Interesting. It's this that is supposed to cause injector failure etc on the TDCi. Metallic bits from the fuel pump rollers can either clog up the filter or knacker the injectors if they get that far. Poor really.

Is it still the case on the PSA sourced TDCi 136?

poppycock! I let mine run down as close to 0 as possible, sometimes ON 0 - Usually when the buzzer goes off I run through the plans for the next couple of days and think where's best to fill up. Not had any sediment issues in 100k+

It buzzes on 0? The lowest i've had mine to is 15 miles left but when it went in to get the bushes replaced I recieved a diesel octi elgence which was given to me with 15miles left in it so i took it back with 5 miles left. Honestly i've never sweated as much as i did when i was 5 miles away from the dealer, stuck in traffic and the display reading 5 miles till empty - I free wheeled into the car park and dumped the thing in the first space lol.

It buzzes on 0? The lowest i've had mine to is 15 miles left but when it went in to get the bushes replaced I recieved a diesel octi elgence which was given to me with 15miles left in it so i took it back with 5 miles left. Honestly i've never sweated as much as i did when i was 5 miles away from the dealer, stuck in traffic and the display reading 5 miles till empty - I free wheeled into the car park and dumped the thing in the first space lol.

I've done more than five miles past zero , and there was nearly a litre left in at this point

The only problem I can see with running near empty is the pre-pump at the tank sucking in air when the tank is nearly empty. Sudden changes from fuel to air won't do the pump any favours.

It buzzes on 0? The lowest i've had mine to is 15 miles left but when it went in to get the bushes replaced I recieved a diesel octi elgence which was given to me with 15miles left in it so i took it back with 5 miles left. Honestly i've never sweated as much as i did when i was 5 miles away from the dealer, stuck in traffic and the display reading 5 miles till empty - I free wheeled into the car park and dumped the thing in the first space lol.

Nope, it buzzes around 65/70 miles to go, but the reserve tank means there's plenty of leeway, even when it gets to zero. When I did run it for 20 miles on zero, when I actually filled up I vented it a fair bit, and managed to get 52 litres in it. Not bad for a 45 mile tank. I never worry when the miles gets low. Zero does mean it's going to conk out - it's just a system fitted by Skoda (et.al) to keep people aware. If they'd designed it so it ran out on 0 to go, it would be a bit silly.

i've run mine many times to very low miles remaining , even zero a few times , when i changed my fuel filter at 40k , i totally drained the filter of the fuel , just to check what , if anything was collected in it , got to say , absolutely nothing came out , that includes the water drain at the bottom

the same couldn't be said for the filters we check on some Fords , not only are they full of 5h1te , but also metallic particles from the fuel pump, these are even visible on the latest Focus 2.0 TDCI

:confused: that would suggest the Ford filters are doing the job and the Skoda ones are letting all the cr@p in the engine?

I've always run my cars tanks down to empty before filling them up, never had any issues doing that with the Superb or the Mondeo, always use supermarket fuel too.