Sabtu, 23 Ogos 2008

Sejauh mana kebenarannya

The bench tests were done on standard ASTM test benches/procedures and the engine tests were done on a Perdana V6. For Petronas samples, the results u see are from the Klang Valley Deport Terminal (KVDT) where both Shell and Petronas fuel for Klang valley come from. Here goes:

Sulfur levels

Petronas Kertih has the least sulphur content - Euro 4 compliant levels, probably due to the sweet crude oil they refine over there. but for Klang Valley residence the sequence goes like this:

1. ExxonMobil
2. Projet
3. Petronas
4. Caltex
5. Shell V-power
6. Shell Super
7. BP

Please note that the difference in sulphur level is great, from Euro 4 compliant to MS compliant which is set at 1000 ppm. A few samples have less than 10 ppm sulphur!

Benzene content

Benzene is poisonous and a know carcenogen(cancer causing element) All have around 2% to 4% Benzene. Best(lowest) being BP, worse being ExxonMobil.

MTBE

MTBE is an oxigenate. it provides some 'built in' oxigen in the fuel so it burns more completely. Nevertheless, MTBE takes up the 'space' that would normally be taken by hydrocarbons(petrol components) thus adding MTBE actually reduces the energy content of the petrol thus lowering fuel economy. MTBE is also outlawed in USA and certain EU countries as it's also poisonous. MTBE is a chemical, not a hydrocarbon but adding MTBE is not considered as adding an additive as anything more than 5% volume added to the fuel is not considered an additive. Additives are added in the Parts Per million (PPM) level, not %volume. Here's how the brands stack up (1 being higest % of MTBE):

1. BP
2. ExxonMobil
3. Caltex
4. Petronas
5. Projet
6. Shell V-power
7. Shell super
The ranges are from less than 1% to almost 15%.

Olefins

Olefins are a refinery product that is regulated it's content in the EU but not regulated here in Malaysia. They tend to give out alot of bad emmisions.
Olefins are short chain molecules that burn very quickly hence giving the user a sence of 'better pick up'. Shell fuel has the most Olefins by far, double the next brand. Shell V-power and Shell super have the same Olefin content.

1. Shell Super
2. Shell V-power
3. BP
4. Petronas
5. Caltex
6. ExxonMobil
7. Projet

Detergent additive content

Measured in PPM. This additive give the cleaning effect of the fuel. Please note that GDI/FSI perfomance is not very effected by the cleaning effect of the fuel as the injector is inside the cylinder. The tops of the valves are not cleaned by the fuel hence FSI/GDI engines will benefit less from the detergent effects of the fuel. One noteworthy observasion is that Shell V-power has double the additive treat rate as Shell Super. Here's how they
fare:

1. Shell Vpower
2. Petronas
3. ExxonMobil
4. BP
5. Caltex
6. Shell Super
7. Projet

Fuel Economy

All candidates did between 11 and 12 litres for every 100km ran. Best being Petronas, worse being Caltex. You get more miles with Petronas apparently than Shell.

Power

Power was measured at 6000rpm. The range from best to worse is only 2.5 hp.
Best being Shell Super and worse being BP. Shell super gives out 2 hp more than Shell V-power! supprise supprise.

Torque

Torque was measured at 5500 rpm. The difference best to worse was 4 Nm. Best being Shell Super and worse being BP.

A slight note on RON 92 fuels. Out of the ones tested, only Projet, BP and Caltex RON 92 fuels had significant additive contents. Others either had very little or no additives what so ever.

From the data I gathered, I think that ExxonMobil (Esso and Mobil) fuel is the best, marginally better than Petronas and Shell. Shell Super and Shell V-Power are the same, the difference being that V-power has double the additive treat rate.

____end of article____

N/B: AS Shell and Petronas have refineries in Malaysia, there will be fluctuations in the quality of the mixture as all petroleum is "mixed" with the various additives which each petroleum company claims to be better than the competition. Please do not attempt to "mix" in MaxKleen9 /Fab / Dettol etc detergents in some false hope of getting better "cleaning" mix for your engines....

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