Filling the Tig with Diesel

[Arctra]

Diesel in petrol cars is far worse!
Or, apparently, unleaded in diesel BMW, as they use different fuel pumps that need replacement at great cost.

Wha? Diesel mixed in petrol isn't bad. It might stuff up ur cat converter, and will certainly make your car smoke more, but because diesel is effectively an oil, it's not really a big problem (as long as there isn't too much mixed in of course). Before anyone tries to jump down my throat about this being rubbish, I'd just like to point out I know this from personal experience on several occassions with 2 different petrol cars (one with the old traditional carb, and one fuel injected).

It's the petrol in diesel that's the big problem as I understand it due to the fact that petrol doesn't detonate under pressure like diesel. This is the first time I've heard of diesel being thinned with petrol, and certainly the first I've heard of anyone sucessfully running their diesel vehicle after puting a few litres of pertol in the tank. Did you notice the engine running any differently? How big a tank was it that the 10l was mixed in? I've certainly learned something new today, thanks!

[NZTiguan]

How much is diesel vs petrol in NZ? Currently diesel in our area is 125.9 and petrol is 121.9. I noticed once when I was holidaying in NZ that diesel was a lot cheaper than petrol which made me wonder if diesel cars might be more popular in NZ than Australia.

You're quite right, diesel is much cheaper than petrol here currently $1.08 for diesel and $1.73 for 96. We then pay a separate "road tax" but that still makes diesel cheaper and when fuel consumption is taken into account it's probably 20% cheaper running a diesel overall.

Can't understand for the life of me why diesel is dearer in other countries, makes no sense at all as it costs less to produce (less refining involved) the same to transport and distribute. Guess it's just a supply and demand issue ??

Cheers

[Tigga1]

It's the petrol in diesel that's the big problem as I understand it due to the fact that petrol doesn't detonate under pressure like diesel. This is the first time I've heard of diesel being thinned with petrol, and certainly the first I've heard of anyone sucessfully running their diesel vehicle after puting a few litres of pertol in the tank. Did you notice the engine running any differently? How big a tank was it that the 10l was mixed in? I've certainly learned something new today, thanks!

Not really running differently, perhaps a smidgin less power. And, as soon as the tank went down I filled her up again. Golf V has 55 ltr tank from memory.
When I completely filled the tank and got stuck, it cost me around $165 (from memory) for draining the tank and cleaning, which I thought was a reasonable price to pay for my mistake.

[Ivica]

Hi Guys,
This is probably a very silly question - but....when should you fill up a diesel tank...is it not too good to let the diesel go down to almost empty and then fill up the whole way? should you not let it go down below 1/4 tank before filling etc....

[tighappy]

As far as I can remember during the long dark freezing days in England truck drivers used to put some petrol (say 4 litres in 65 litres tank) in their tanks to stop waxing up. It did boost the performance slightly but it was the older type of engines definately not recommended for modern engines as the sensors are looking for oxygen levels and want more fuel and when it doesn't recognise the cleaner fuel and never reaches the level required reving can blow the engine.

Also if you are in a cold climate you shouldn't let your tank empty to prevent condensation forming.

Just glad I'm far north coast NSW where these thoughts are left far behind

[NZTiguan]

Hi Guys,
This is probably a very silly question - but....when should you fill up a diesel tank...is it not too good to let the diesel go down to almost empty and then fill up the whole way? should you not let it go down below 1/4 tank before filling etc....

I just fill up when my Tig "asks" which is a bit under 1/4 full, but with todays clean fuels It wouldn't worry me running it pretty low if I had too.

Cheers

[Ivica]

Thanks Derek !!

[Transporter]

I don't like to let the fuel level drop below 1/4.
Less fuel you have in tank, hotter it gets and it will form water condensation in the tank, affecting fuel pump and other delicate fuel injection components.

Just my 2c.

[T&M]

It's the petrol in diesel that's the big problem as I understand it due to the fact that petrol doesn't detonate under pressure like diesel. This is the first time I've heard of diesel being thinned with petrol, and certainly the first I've heard of anyone sucessfully running their diesel vehicle after puting a few litres of pertol in the tank. Did you notice the engine running any differently? How big a tank was it that the 10l was mixed in? I've certainly learned something new today, thanks!

Hi mate, yes you'll hear the old timers say that a bit of petrol in your diesel tank want hurt it. Maybe the older engines handled this OK, but I wouldn't try this in mine. Some also say that if you get a bit of water in your diesel tank, that adding the ULP helps too... again I would do this either. Same with the old metho in your tank etc etc...
Having said that, if you "accidentally" get some ULP in there (depending on how much) you either have to fill the remainder up properly with diesel and 'thin' it, maybe even pour in an additive of some description, or if it's a tank full - don't even start it - get a tow and drain the tank.

If ULP works as an "antifreeze" on some old truck that is 671353553 years old, it doesn't mean that it will be OK in a new CRD diesel...
That's why the diesel fuel in cold climate locations has an anti-parrafin-wax agent included to stop it turning into gel. Our Alpine mates will confirm that.

[jimbomort]

price of diesel in Oz

You're quite right, diesel is much cheaper than petrol here currently $1.08 for diesel and $1.73 for 96. We then pay a separate "road tax" but that still makes diesel cheaper and when fuel consumption is taken into account it's probably 20% cheaper running a diesel overall.
Can't understand for the life of me why diesel is dearer in other countries, makes no sense at all as it costs less to produce (less refining involved) the same to transport and distribute. Guess it's just a supply and demand issue ??

As far as I know Diesel is less costly to produce, though it is also more 'energy dense' per litre. I am not sure if that means more raw petroleum is used to make it. The Diff b/w Oz and NZ on fuel price may be due to differences in taxation (fuel excise).

As far as I know Australia pays the Spot Price for Diesel in Singapore (at least during times of high demand) as we are a relatively small buyer (albeit probably bigger than NZ I expect). During periods of high demand countries like China and have most of it tied up in large contracts/purchases. That is why during the financial boom when fuel prices went up some may remember that diesel ended some 15c or so more per litre than unleaded 91 (about same if not more than premium 9. I expect when demand for fuel fires up again, diesel as before will increase more than petrol because of this lnik to spot prices in Singapore.

This potnetial for more expensive diesel was part of our 'weighing up' when buying a petrol tig (though not as important as performance), but just when this will happen is anyones guess. At the moment diesel can often be a few cents less than unleaded 91 and up to 15c less than Premium. A bonus for diesel tig owners to help offset the higher purchase cost.