FREEZING DIESEL

[HenryS]

'Morning all. The local news broadcasts here in Northern Ireland are reporting that some motorists are having problems with the diesel freezing or gelling and engine failing to start. Minus 15 is fairly common at present. I had a word with my dealer who said that he had heard of this and that the trade were of the opinion that this was more likely to happen with fuel bought from the supermarkets. (I thought we all got our fuel from supermarkets !). I have read that the refineries introduce an additive in winter to prevent freezing, but this is only effective down to a certain degree of frost. I am fortunate in that I keep my car garaged overnight and I have not had any trouble in starting, however, I was wondering if others were having this problem.
Henry

 

[emmerson]

This used to be a common problem thirty or forty years ago, but I've not heard of it recently. It must be really cold over there!

 

[forestgump]

all our cranes and heavy haulage are frozen due to this new bio fuel good for the planet but not so good for busisnues,

 

[ChrisUK]

I read in the paper yesterday that standard British diesel fuel is rated down to -15 C. As someone who remembers all the buses griding to a halt in 1963 this did surprise me.
Yet another reason for not using supermarket fuel. Odd in my town as there are always queues at Tesco / Sainsburys, but not at the smart town center BP garage, yet the price is nearly always the same?

 

[OmOnWeelz]

Our local Sainsbury sells about 50 times as much fuel as the nearest BP or Total stations. If Sainbury's fuel didn't have antifreeze addatives most of the diesel cars around our area wouldn't have gone anywhere in the past couple of weeks and in the last big freeze earlier in the year. We've also tried Shell sooper dooper diesel against Sainsbury's and there was no noticable difference in running or mpg with both of us driving the car.

 

[SirRogerFFS]

If the temperature is dropping that low and causing you problems you can add about half a ghallon of petrol to you tank this will prevent the diesel jelling.
Again this I believe to a Supermarket problem as there fuel does not have the additive needed
Locally we have a Total station that economically is terrible and have had bad results with Supermarket fuels so I always stay with proprietary brand fuel, and I believe Shell to be best but that maybe because its suits our vehicles best
Sir Roger

 

[OmOnWeelz]

If you're smart you will not add any petrol to the tank of a modern day diesel car

"A lot of old-time mechanics added some gasoline to diesel to supposedly clean the carbon deposits out of the cylinders. I have never read anything that said it worked. Gasoline will make the fuel burn hotter, and hotter burning fuels burn cleaner. That’s probably where the theory got started. In the older diesel engines that belched lots of black smoke even when properly tuned, the result of adding gasoline was probably more white smoke instead of black. This might lead one to believe the engine was running cleaner. Maybe so, probably not. Here’s what happens.
Gasoline will raise the combustion temperature. This might or might not reduce carbon deposits in the cylinder. This also might or might not overheat the injector nozzle enough to cause coking on the nozzle. That’s a clogged injector tip in layman’s terms. The fuel being injected is the only thing that cools the nozzle. Diesel fuel has a lower combustion temperature than gasoline. The fuel injectors depend on the fuel burning at the correct rate and temperature for a long life. If the combustion temperature is raised long enough, the gums and varnishes in gasoline will start to cook right in the fuel injector and turn into carbon. These microscopic carbon particles will abrade the nozzle. High combustion temperatures alone will shorten fuel injector life, gasoline makes the problem worse.
Gasoline and alcohols do have an anti-gel effect on diesel fuel, but these fuels are too thin and will hurt the lubricity. Alcohols work as a water dispersant in small amounts, but also attract water in large amounts. Diesel fuel is already hydrophilic (attracts water) so why add to the problem. The old timers got away with this because high sulfur diesel fuel had enough lubricity to take some thinning. Today’s low sulfur diesel fuels have adequate lubricity, but I wouldn’t put anything in the tank that would thin out the fuel, reduce lubricity, or attract water.
Opposites do not attract in this case. Use any of the diesel fuel additives available to clean out carbon deposits, not gasoline or alcohols"

If you really want to ruin modern diesels and pay huge repair bills just risk adding petrol.

 

[colin-yorkshire1]

hi. very informative and quite correct however a couple of things were missing.
1. diesel fuel increases in viscosity the lower the temperature gets down to the point it starts freezing or waxing but can be significantly thicker when temperatures get down to 0 degrees immaterial of wether a additive is used or not. inorder to combust in the cylider the fuel as to be atomised at the correct time in to the hot air of the compression "hence the use of heater plugs" for cold starting if the fuel is cold and therefore thicker it will not atomise correctly and prevent starting.
2. to combat this most diesel cars have a fuel heater usually in the diesel filtre that heats the fuel as it passes into the distibution pump "DPA" it is not uncommon for fuel heater to stop working and if a engine is hard to start in cold weather is allways worth checking this aswell as the operation of the heater plugs.

colin.

 

[JTQ]

My take on it:

In earlier times more of the "wax" content was left in what we purchased as diesel fuel. This was simply a commercial decision in that diesel engines could burn the wax and so it could be sold on that way. The waxing content was also a welcome lubricant so also brought benefits. In the colder months the wax formed a crystalline matrix that jammed up the fuel system in general, pipes from the tank filters pumps etc.
For winter the wax content in the fuel leaving the refinery was reduced to help get over this and yes users to further help keep the wax in solution often added petrol or kerosene. The diesel pump technology, particularly the very much lower injection pressures used at the time meant they got away without much damage.
To further help, the fuel systems of the time also often featured in filter heaters to keep the wax from crystallising, but these only dealt with wind chilling effects on the road after starting.

Things have changed very much now and with the near total removal of sulphur bearing compounds of the mineral oil derived part of the fuel. With this most of the wax has also gone so the diesel fuel of today is inherently more able to withstand getting cold. Unfortunately now there is an increasing amount of bio-derived product in the fuel some of the cold temperature coagulating issue is returning.
I don’t think there is much difference in the problem wherever the fuel is purchased, as apart from the additive pack the base stock diesel is the same.

The adding of petrol or kerosene to modern diesel engines is a fool’s game. It might just ease the slight issue of waxing in today’s fuel but it will reek havoc with the lubrication of the pumps, injector needles etc in today’s technology equipment operating at many times the pressures of even a few years ago.

The glow plugs serve no function in fuel heating whatsoever. They are there solely to create a hot spot in the cylinder to initiate combustion when the engine and intake air is so cold that at starter cranking speed the compression alone cant develop enough heat to do the job.

 

[Surfer]

When I used supermarket fuel in my diesel on start up in the mornings it would belch loads of smoke and ther was a noticable drop in mpg. I prefer Shell but otherwsie use BP although BP is always at least 2p mole than any other service station. Also found that on my wife's petrol car we got more mpg than supermarket fuel and also smoother running.

 

[ChrisUK]

About 10 years ago I did a job at a well known engine developement company, all the very big names use them, and the guy I was dealing with said that he would never put supermarket fuel in his own car. They analysed all the fuel they put in the engines. He would not tell me which brand he actually used though. Since then I have tried to stick to Shell / BP / /Total in that order. I do know that when I am forced to use brand X in the Scotish islands for weeks on end the engine gets (Xtrail diesel) very noisy and you can almost here it give a sie (sye - can not spell it) of relief when I fill up in Oban with some good stuff.
DFPs are an additional reason for using good stuff but perhaps I am going even further off topic.

 

[ChrisUK]

About 10 years ago I did a job at a well known engine developement company, all the very big names use them, and the guy I was dealing with said that he would never put supermarket fuel in his own car. They analysed all the fuel they put in the engines. He would not tell me which brand he actually used though. Since then I have tried to stick to Shell / BP / /Total in that order. I do know that when I am forced to use brand X in the Scotish islands for weeks on end the engine gets (Xtrail diesel) very noisy and you can almost here it give a sie (sye - can not spell it) of relief when I fill up in Oban with some good stuff.
DFPs are an additional reason for using good stuff but perhaps I am going even further off topic.

 

[xtrailman]

I have used supermarket fuel in every car since supermarket fuel was available.
Never had a engine problem, always got the average fuel figures.

Even the Audi quattro i had designed for 180bhp with 98 octane, worked fine on lower octane supermarket fuel.

The only time i have ever had a fuel problem was back in the 70's, when i bought from an independent, found water in the float chamber of the carburetter.

 

[Surfer]

DPF is a very good reason not to use supermarket fuels!

 

[OmOnWeelz]

Pals business has two Articulated lorries, three vans, Voyager, Merc and his own 335M sport Diesel. The fuel bill for a small high mile business is huge and most of the time they've used supermarket fuel for the past 5 years. The two truck drivers are old hands who get every last mile per gallon. It annoys them to fill up on a slow supermarket pumps but they get the points on there customer cards. MPG on 6 trucks since the business started has been no different. And neither the Merc nor the 3 sreies show any difference using Shel or BP. Buying the more epensive Shell fuel for a run back from Scotland the 3 series still gave the same average MPG. When serviced none of the vehicles have shown any adverse probs and they do far above average annual mileage.
At the moment we're using a Q5 Audi. Filled from very empty with Shell this morning and have been to Taunton and Bristol on a round trip of 245miles solo, still recorded same MPG Solo when car has normaly has 3 of us in recently.
I tried everything to get more MPG from the Disco 4 we recenly got rid of, nothing made any difference in that. It was cr-- MPG whatever you did with it

Never had black smoke problems on SM diesel either.
Refinery chemist guy told me never use the same fuel all the time so when out and about our cars get the odd tank of BP or whatever station pops up.

 

[HenryS]

Thank you for your various replies. The temperature at Castlederg, Co. Fermanagh at 8.00am this morning was minus 17 and last night it touched minus 18. Our local radio is reporting that people with oil fired central heating, where the supply pipe from the storage tank to the boiler is above ground, are having problems with the oil freezing in the pipe, resulting in the boiler not operating. Kettles of boiling water and hair dryers seem to be the order of the day in Co. Fermanagh. Happy Christmas to all.
Henry

 

[forestgump]

i worked at oil refinerys for many years and shell and BP are the same company and thers no diffrence in the fuel.

 

[ChrisUK]

i worked at oil refinerys for many years and shell and BP are the same company and thers no diffrence in the fuel.

Insn't the main difference in fuel the different additives the delivery guy puts in. The brand x stuff on the isle of Mull is supposedly Shell, but even my wife comments on the difference in engine noise compared with Real Shell on the mainland.
Somewhere else on the forum (or may be the XTrail forum I use) listed the Cetin number (I think thats how you spell it) and there are marked differences between the minimum requirement and the value for the good brands. (I must do a seach for that).

 

[SteveW77]

In the 45years I have been in the motor trade I must have taken delivery of hundreds of tanker loads and I never ever saw a driver add anything to the loads before discharging into the storage tanks. When my site sold Esso fuel, we used to share a delivery with the National site 2 miles down the road and although the octane rating shown on their pumps were slightly higher that those on our pumps, I can assure you that the fuel was exactly the same.

Steve W

 

[DerektheSecond]

i worked at oil refinerys for many years and shell and BP are the same company and thers no diffrence in the fuel.

Insn't the main difference in fuel the different additives the delivery guy puts in. The brand x stuff on the isle of Mull is supposedly Shell, but even my wife comments on the difference in engine noise compared with Real Shell on the mainland.
Somewhere else on the forum (or may be the XTrail forum I use) listed the Cetin number (I think thats how you spell it) and there are marked differences between the minimum requirement and the value for the good brands. (I must do a seach for that).

Its the same firm that supplies Mull and the two independents in Oban, Gleaner/shell.
I use Tescos or the Esso garage at Dunbeg or shell or if Ive forgotten any of the garages on Mull (and pay the extra

)and and have not noticed any difference either in my own car or the works vehicle.
saying that our neighbours heating oil froze yesterday and she hasnt had any heating

 

[Philspadders]

i drive around 400 miles per week on a mix of motorway and urban.
I fill up with what is available, Morrisons, BP, Sainsbury, Texaco, Murco etc
Ive not noticed any difference in mpg , power, acceleration , no increased engine noise and certainly no smokeand since the car is company owned and i dont get private mileage i record very carefly my mileage and fuel usage for so dont get hammered on my p11.

Sometimes however , the bio % of the fuel can contain a little more water / methanol than it should and its this that can cause some issues.However all diesels have a water trap in the system and if yours is running poorly it may need draining.
Many manufacturers hand books prescribe limits on the percentage of bio fuel that can be used, primarily because the methanol can cause damage to various parts of the fuel train and lead to poo running due to its low cetane rating.

I have 2 diesels at the moment and have driven diesels for many years and have found it very uncommon to have a heater in the filter.

 

[emmerson]

I use LPG for everything, and don't have any problems! And its an awful lot cheaper.

(exits with smug expression)!!!!

 

[Steve L]

My Rover 75 diesel was slugish to start yesterday but that was probably due to us having the lowest night temp and lowest day temp in the West mids. -16.9 and -1.4 respectively.
I have heard of people adding paraffin to diesel to make it more sustainable in extreme cold but not petrol.
I would be very carefull adding anything to modern diesels as with all the sensors etc you might cause some damage.
Years ago I used to light a small barbie under my truck to start it as it had naff heater plugs. But you do run the risk of setting fire to the whols chebang!!

 

[colin-yorkshire1]

funny you should mention that steve because my mates tranny had the perkins 2.3 diesel engine that would never start from cold no matter how he tried changed the pump plugs ect no avail then someone told him to light a fire in the air box. and guess what a tissue and a squirt of lighter fluid set fire to it and presto started every time first flick.
dont know if it was the unburned lighter fluid the burning embers of tissue or the hot gas but it worked. he did this every winter for years.

colin

 

[Steve L]

The extra indirect heat thins the diesel making it easier to ignight under pressure. If you use the air box method, you have to remover the air filter as you could set fire to it.