Motormouth Online

 

Is it really important to fill up with premium fuels?

Hi, Ferman!

I'm a regular reader of your column and I find your articles very informative.

I own a Toyota Innova and an Isuzu D-Max. The D-Max is a 2005 model and it's not CRDi. It also had the misfortune of suffering from a choking pump. Isuzu said this was caused by dirty fuel (I've been using regular diesel) and it had to be recalibrated.

Fuel companies tout their premium fuels to cleaner and to offer more power. Aside from the claimed better performance, do premium fuels really have other cost benefits like, perhaps, a longer engine or pump life?

I would appreciate your expert opinion on this matter as some people are not convinced of the benefits of premium fuels.

Thank you and more power.

Al

Hi, Al!

Thanks for being a loyal reader.

To understand the problems that you and many other diesel-engine-vehicle owners encounter, we need to take a quick look at how a diesel-fuel system works.

Like any internal-combustion engine, a diesel engine has a tank, a fuel filter, a fuel pump, and a fuel delivery and metering system. In a gasoline engine, the fuel delivery and metering system can be a carburetor or an injector. In diesel engines, it's the injection pump and injectors.

Fuel is stored in the tank, and it travels to the injection pump and injectors after it passes through the fuel filter. What's critical in prolonging the component life of your engine is the fuel filter. Its job is to catch and prevent contaminants from getting to either the injection pump or the injectors. The contaminants include water, microscopic particles and bacteria, which may clog the fuel system over time.

When any of the components gets clogged, you get poor engine performance because there is no longer sufficient fuel getting to the engine.

On the other hand, when orifices inside the fuel metering system wear down, you are getting much more fuel than required. When that happens, you will see black smoke coming out of your tail pipe.

Either way, you need to get to a diesel center to check the condition of your vehicle's injection pump.

This is what happens during calibration: The line to every injector is checked for pressure and flow-rate capacity. They are calibrated to standard specification as required by the engine manufacturer. Anything that is out of spec is rebuilt, reconditioned, and parts are replaced when necessary.

Unfortunately, injectors are often neglected. Why do they need to be replaced? The answer is simple. They are part of the fuel delivery and metering system, and they are subject to a much harsher operating environment compared to the injection pump. If you are not going to check them for flow rate, volume and spray pattern, and if you don't rebuild them as necessary at the same time you have your injection pump calibrated, you're wasting resources and time, particularly when there's a drivability problem with the vehicle.

Recently, fuel companies have been coming out with diesel fuels claiming to offer better performance while being cleaner and less harmful to the environment. To my understanding, these products have been blended with additives that enhance certain properties of the fuel for the engines to run smoother and cleaner. Do note that if the mechanical aspects of the engine mentioned above aren't in proper working order, then fuel can only do so much.

To minimize clogging and contamination I would use a very good fuel filter, choose where I get my fuel and change the fuel filter at a much shorter interval than required by the vehicle manufacturer. It's cheap insurance against a much more costly fuel system failure.

Hope this helps!

Regards,

Ferman Lao
Technical editor

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Called-Out Comments All Comments
  • dominic Nov 22 2011 @ 10:37am
     
    Thanks for the info sir!
       
  • enZo4o Nov 22 2011 @ 11:04am
     
    thanks for this wonderful info..
       
  • mico101 Nov 22 2011 @ 02:26pm
     
    ano ba symptoms ng poor fuel quality sa gas stations? mahirap alamin kung ano yung good quality kasi hindi ko naman makita yung fuel storage tanks nila.
        1
  • narru18 Nov 22 2011 @ 02:28pm
     
    thanks for the sharing this info... knowledge LIKE!!!
       
  • Romeo Alfa Nov 22 2011 @ 02:41pm
     
    a simple tip:
    Do not refuel if you see a lorry (a gas truck) filling up the gas station's fuel tanks. sediments inside the tank are disturbed causing them to enter your vehicle's fuel tank..
       
  • eddie_g Nov 22 2011 @ 03:44pm
     
    Yung sa Unioil yung diesel nila may nakalagay na 55ppm. Ito ba yung sulfur content ng diesel? How does it compare sa diesel ng ibang oil companies?
       
  • Feeter Silverster Nov 22 2011 @ 09:29pm
     
    FYI, lower sulfur contents of diesel is for euro emission standard compliance, for cleaner emissions. It's not that good for older diesel engines because it got lesser lubricity properties.
       
  • mindkinetic Nov 23 2011 @ 12:51am
     
    nice article mr. fernan .... now il be replacing my fuel filter earlier than the manufacturer's recommendation.
       
    • wart_les Nov 24 2011 @ 01:57pm
       
      The writer sender encountered "Damaged fuel FEED pump" on his CRDi Engine Car...Diesel refining has gone high in its development...It is through improper HANDLING and or its STORAGE that made the diesel fuel harsh to components involve in the fuel system...Diesel fuel specs on analysis has always allowable or minimum water content and so other contaminant substances that will contributes harmful effects to components primarily like the FUEL Feed Pump...It is the fuel feed pump that supply fuel to the INJECTION pump subsequently delivering the fuel at high pressure to the pressurized common rail up then to the Injectors concluding atomized spray. As in every CAR the suction of the Fuel Feed Pump from the TANK is on near utmost bottom and is only having STRAINER, meaning it only restrains solid sidemen’s and not the unwanted in liquid forms substance which combines the volatile hydrocarbons...Most cars of today, the Fuel Pump is positioned inside the TANK compartment. The damaging of the Fuel Feed Pump could be caused by (1) Enormous water presence in the TANK or (2) By so called Cavitations...The FORMER could be addressed by making your tank FULL as often during night leaving NO SPACE for moisture to settle. The LATER happens when not enough STATIC HEAD during the very start of pump running which could cause pump early damage.
      Ultimately, the pump materials should be upgrade and designed to withstand these two criteria mentioned if AFTER SALES is not a matter all and QUALITY is of paramount importance?
      Take to notice that the fuel filter is positioned at the discharge of the Fuel Feed Pump and functions more to safeguarding the Injection pumps…Our case here is the FUEL FEED PUMP that is being
      damaged?
         
  • crispinbasilio86 Nov 23 2011 @ 04:18pm
     
    Primary concern ko dyan yung fuel system baka sometimes may water and impurities na. Routine maintenance yung FO filter by draining to eliminate water or sludge content or replacing it and observe mo muna kung ok. Ok din totally drain mo yung diesel tank mo and para matanggal ang suspected water and impurities. Better mix up mo sometimes ng FO additives (basta nagpa gas-up ka) that serves as cleaning the fuel oil lines kc due to unavoidable circumtances ang fuel oil lines nagkakaroon ng sludge and that's the time affected na ang major mechanical parts ng FO system . if not that's the time pa mo pa re-calibrate ang FO injector kung di pa rin yung FO injection pump. One by one lang para malaman mo ang diperensya.
       
    • wart_les Nov 24 2011 @ 02:01pm
       
      The writer sender encountered "Damaged fuel FEED pump" on his CRDi Engine Car...Diesel refining has gone high in its development...It is through improper HANDLING and or its STORAGE that made the diesel fuel harsh to components involve in the fuel system...Diesel fuel specs on analysis has always allowable or minimum water content and so other contaminant substances that will contributes harmful effects to components primarily like the FUEL Feed Pump...It is the fuel feed pump that supply fuel to the INJECTION pump subsequently delivering the fuel at high pressure to the pressurized common rail up then to the Injectors concluding atomized spray. As in every CAR the suction of the Fuel Feed Pump from the TANK is on near utmost bottom and is only having STRAINER, meaning it only restrains solid sidemen’s and not the unwanted in liquid forms substance which combines the volatile hydrocarbons...Most cars of today, the Fuel Pump is positioned inside the TANK compartment. The damaging of the Fuel Feed Pump could be caused by (1) Enormous water presence in the TANK or (2) By so called Cavitations...The FORMER could be addressed by making your tank FULL as often during night leaving NO SPACE for moisture to settle. The LATER happens when not enough STATIC HEAD during the very start of pump running which could cause pump early damage.
      Ultimately, the pump materials should be upgrade and designed to withstand these two criteria mentioned if AFTER SALES is not a matter all and QUALITY is of paramount importance?
      Take to notice that the fuel filter is positioned at the discharge of the Fuel Feed Pump and functions more to safeguarding the Injection pumps…Our case here is the FUEL FEED PUMP that is being
      damaged?
         
  • torquebender Nov 23 2011 @ 06:19pm
     
    ung mitsubishi adventure namin, napakaitim ng usok, nung pinacalibrate namin P10,000 ung nagsatos nmin
       
  • crispinbasilio86 Dec 04 2011 @ 05:55am
     
    Most Diesel Engine Failures Originate In The Fuel Tank

    http://www.diesel-fuels.com/
       
  • safariboi Dec 09 2011 @ 07:44pm
     
    Also don't forget to fill fuel treatment in you fuel tank which can help to clean your injectors everytime you will have your car check for maintenance.
       
  • rajesh Jan 24 2012 @ 02:15am
     
    hi ferman,

    what could be the probable causes if the crdi injectors are over fueling ......
       
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