Saturday, Apr 14, 2012 at 13:56
Gazz -
Well, here's my .03c worth (allowing for inflation). I can't say I've ever found a really noticeable difference between fuel brands. However, different servos and roadhouses will provide differing fuel quality. Be very aware that numerous servos have serious problems with tank contamination, due to leaks caused by corrosion that creates pinholes in underground tanks.
These older tanks can also have contamination created by poor location of underground tank filler necks and vents (i.e. - they go under water when there's heavy rain).
The older servos and the servos in remote areas generally have older tanks. Older tanks were never installed with the same degree of protection from corrosion as new tanks. Older tanks were just coated with a bitumenous coating, and dropped in the ground and covered over. As a result, these tanks are very prone to corrosion, and therefore contamination, and leakage. It's worse if the natural soil profile is heavy clay.
Now, the authorities don't give the proverbial rats rectum about fuel contamination - but they sure do care plenty about fuel leakage from underground tanks. Fuel leakage contaminates groundwater aquifers, rivers, and waterways.
As a result, authorities now place probes within a short distance of all older tanks (particularly in metro areas), and if those probes pick up fuel leakage - whammo - if you're the servo owner, you're hit with a tank replacement order that must be carried out urgently.
Every time you see a servo forecourt ripped up and new tanks going in, then you know the previous tanks have been leaking. Leaks are a major headache for servo owners, because it's $$$ losses to them.
However, if the tanks merely develop pinholes on the top side, this will create minimal fuel losses, so it won't usually be picked up by probes (or it will take a long time) - BUT, this is the situation where regular fuel contamination occurs.
Bowser filters are not 100% effective in preventing contaminated fuel from reaching your fuel tank.
Nowadays, new tanks undergo substantially improved techniques in coating and installation methods. The new coatings are more durable than the old bitumenous coatings, and the installation technique nowadays is similar to new landfill techniques, where the hole is lined with an impermeable geotextile fabric, then sand is placed on the fabric, and the tank installed on the sandfill, and then covered over.
The leakage probes are then placed in the sand fill. The sand, being highly permeable, allows prompt identification of fuel leaks - and the geotextile fabric prevents any fuel leaks from entering groundwater supplies.
As a result, newer underground tanks are a far better bet, than tanks that are 20 yrs old or more. There is far less chance of contamination due to newness, improved coatings, and improved installation methods, that also involve better placement of fillers and vents.
Then comes the fuel turnover rate. Be aware that we have "Summer" and "Winter" grades of diesel in Australia. The fuel companies will never tell you this, they just refine the fuel to varying volatility levels, according to whether they reckon it's going to be used in a cold area or a hot area.
Diesel Fuel is basically refined to a standard set by the Govt (called the Fuel Standard (Automotive Diesel) Determination 2001).
This standard has been amended slightly a few times since 2001, to accommodate biofuels and constantly reducing sulphur levels.
However, the refining parameters of diesel fuel can be "tweaked", and the fuel companies do this with additives and modified refining techniques. They also have to deal with varying qualities of crude oil that means they often need to fiddle with the refining process to reach the fuel standard.
The fuel companies refine Winter fuel with a few more volatile compounds, and less wax content, to improve cold starting and operation at low temperatures. When they refine Summer grade, they up the wax content, and reduce the volatility.
Up in the Alps around Kosciusko, you need Winter grade for much longer than any other part of Australia. In
Alice Springs, you basically don't need Winter fuel for any more than June and July.
When a servo has big tanks and a low turnover rate, you could be getting Winter grade long after Winter has ended - or Summer grade when Winter has commenced.
The slightly improved volatility of Winter grade, being used in Spring or Summer could provide a noticeable difference in performance. The higher wax content of Summer diesel will reduce fuel filter life.
Gazz, you're spot on with regard to the fussiness of the new common rail diesels to fuel cleanliness and quality.
The old oil burners had no electronic injection controls, ran at low injection pressures (say, around 1500psi - 3000psi, in the old money), had big injector orifices, and would basically run on any black-looking stuff that flowed.
I can recall my brother running out of diesel once and making up a brew out of kero and lube oil, that the old HJ61 Tojo ran on quite happily for several hundred kms.
However, we're in 2012 here, and the new diesel engines are running at injection pressures in the order of 25,000 psi - 30,000 psi. They have electronically-controlled injection that often even gauges the viscosity parameters of the fuel being injected, and they will shut down the ECU if the fuel doesn't meet the programmed parameters.
The new electronic injectors are electronically pulsed, firing fuel into the combustion chamber in several pulses during the injection period, to reduce diesel knock and to improve the combustion process for more thorough burn and reduced emissions.
As a result, the new motors need PERFECTLY clean fuel - and fuel that meets far more stringent and more narrow parameters as regards contaminants, viscosity, and sulphur content, than what an old Tojo or Patrol will require.
Most new vehicles have barely adequate fuel filtering systems (due to bean counters cost restraints) - and fuel filter maintenance is often seriously neglected - particularly with regard to water contamination.
I would advise that you fit an additional top-quality, fuel filter arrangement, that has a water separation facility included in its construction. There are quite a few of these units available, and they are a very good investment in these days of high tech diesels, and the need to keep fuel parameters within a much tighter range, than the good ole days.
Cheers - Ron.
AnswerID:
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Follow Up By: Member - Mark E (VIC) - Saturday, Apr 14, 2012 at 18:56
Saturday, Apr 14, 2012 at 18:56
Wow....what an informative post.
Thanks Ron, it's much appreciated. I learned quite a bit here.
Cheers,
Mark
FollowupID:
758328
Follow Up By: Member - Outback Gazz - Saturday, Apr 14, 2012 at 19:50
Saturday, Apr 14, 2012 at 19:50
G'day Ron
Same as Mark E - very informative reply - much appreciated !!
I'm sure many others learnt something here as
well. I'm certainly going to look into an added filter of some sort after I get my hands on the new
Ranger ( I don't like drinking contaminated beer so I'm guessing the new diesel engines don't like drinking contaminated fuel ) It was also interesting to hear about the exchanging of fuel between fuel companies from Bob.
The lesson learnt - if you want longevity and trouble free motoring from your modern day common rail diesel - install a secondary fuel filter and replace them regularly !
Thanks to all who replied
Happy travelling
Gazz
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758338