V-Power - Hmmmm.....

[Schwepps]

It shows ok with ron 95 to 98. Anyway, I'm ok with ron 97 price as my monthly mileage clock is not high. It is averagely at 1,500 to 1,800 kms per month. So... the monthly petrol price is still tolerable for me

Then it's not that it's not advisable, you just prefer RON97 fuel and have lots of dough.

To most people, the term 'high octane' means 'more flammable' and 'higher energy'. In fact the exact reverse is true: higher octane means less propensity to self-ignite! The energy level is the same, in the same base fuel. In other words, RON 95 is more flammable than RON97 but the calorific value is the same. See http://en.wikipedia.org/wiki/Octane_rating , or google 'octane'.

ULG95 and ULG97 have the same calorific values, it's just that ULG95 burns marginally more easily than ULG97. ULG95 is subsidised by 30 sen per liter, and ULG97 is not. It's every car owner's decision to make of course. For me, it's ULG95 for city, VPower for outstation.

 

[David Yong]

In fact I love VPower. Will always try to get VPower whenever possible but too bad that it's hard or I mean it is not that easy to find one nowadays. I find VPower gives me more mileage.

 

[Schwepps]

Schwepps, I heard the rattling sound of the engine when on low rpm. Is this the side effects of Ron 95 ? Other than that, no issues on Ron 95.

That's not knocking, et. Knocking is a metallic pinging sound caused by spontaneous combustion under high compression and high temperature. Knocking happens under heavy acceleration, not low RPM or decceleration.

Anti-knock is added to raise the octane level of a gasoline to make it LESS susceptible to self-combustion. The first form of anti-knock agent was lead. Now they use safer agents. http://en.wikipedia.org/wiki/Antiknock_agent

 

[glock_8]

Then it's not that it's not advisable, you just prefer RON97 fuel and have lots of dough.

To most people, the term 'high octane' means 'more flammable' and 'higher energy'. In fact the exact reverse is true: higher octane means less propensity to self-ignite! The energy level is the same, in the same base fuel. In other words, RON 95 is more flammable than RON97 but the calorific value is the same. See http://en.wikipedia.org/wiki/Octane_rating , or google 'octane'.

ULG95 and ULG97 have the same calorific values, it's just that ULG95 burns marginally more easily than ULG97. ULG95 is subsidised by 30 sen per liter, and ULG97 is not. It's every car owner's decision to make of course. For me, it's ULG95 for city, VPower for outstation.

but our car rated power is tested and dynoed based on ron 98. Using the 97 alone has degraded the performance of our car's engine. let alone the 95.
why buy expansive performance car when u want to save of few cents of fuel per liter?

as for dy...his high performance car sure doesnt do justice if he uses ron 95 hahaha....

 

[Schwepps]

Your statement is totally off if you understand the chemistry of gasoline and the mechanics of combustion engines. Anyone who wants to pay extra to get the same product is perfectly entitled to. It happens all the time.

 

[infinityKL]

alfa's seems to have some knocking issue's wt ULG95 or V power... ? ULG97 is the prefered choice by many...

 

[Schwepps]

If their engines knock with VPower, they would also knock with ULG97. Same RON...

 

[astroboy]

Sachseelan will ask u how came some people can drink more Whiskey and not Vodka when both having same alcohol content of 40%? :24:

 

[ALBundy]

On my car with 3 adults and 2 children, at 100km/hr constant speed and relatively flat surface my car averaged 7.8 liters/100km on the highway.

As for city driving, it mainly boils down to 1) traffic condition and 2) the type of foot you have, whether its coated with Lead or not.

AS for RON 95 or 97, I do feel the engine is marginally meatier with RON 97 but am using RON95 most of the time not so much due to the price, but because of its significantly lower sulphur content.

Cheers

 

[e60FANster]

my average on my 335i is 14.6 l/100km and i'm on ron 97

wei.. kenot be la, dat's 6.8km/l which is damn blardy gud given its a TC.
wat do u do cruise all the time at 90km/h and on e highway as well.
at times wen i'm really heavy footed, i only get 6km/l my worst ever full tank of vpower

 

[infinityKL]

hmmm.. i nevr tried the 95 or V on the alfa yet... was just being safe based on info from the darkside hehe... however, i still love the V !! should give it go on the italian...

vodka and whiskey... ohhh they are just as good when comes to alco level but they have diff % proof volume.. aiya dont care la.. janji mabok...

btw, im not really intrested on FC or price.. i just want the best suited fuel for my cars..

 

[Traveler]

AS for RON 95 or 97, I do feel the engine is marginally meatier with RON 97 but am using RON95 most of the time not so much due to the price, but because of its significantly lower sulphur content.
Cheers

How would we know the sulphur content of our fuels? Are they publicly available somewhere?

I use RON95 because I have an aversion to "wasting" a more premium fuel on traffic jams and crawling to work and back. I'd much rather use the premium fuels when I am going on long distance drives. That and the fact that I feel we are being taxed to death, so I'll take my subsidy anyway I can

 

[Schwepps]

wei.. kenot be la, dat's 6.8km/l which is damn blardy gud given its a TC.
wat do u do cruise all the time at 90km/h and on e highway as well.
at times wen i'm really heavy footed, i only get 6km/l my worst ever full tank of vpower

A turbocharged engine is more efficient than a normally aspirated engine, which is why the future is fewer cylinders, smaller capacity and turbocharging to SAVE depleting fossil fuels.

 

[Schwepps]

How would we know the sulphur content of our fuels? Are they publicly available somewhere?

Shell ULG95 and ULG97 would have the same sulphur content (whatever that is) as they're the same base gasoline coming through the same pipeline from Shell PD. In fact, on occasions when there is shortfall in Shell production, you might even be pumping Petronas base gasoline from Petronas Melaka. That's how it works folks.

 

[David Yong]

wei.. kenot be la, dat's 6.8km/l which is damn blardy gud given its a TC.
wat do u do cruise all the time at 90km/h and on e highway as well.
at times wen i'm really heavy footed, i only get 6km/l my worst ever full tank of vpower

It's true my friend. The max I have been up to is 14.8l/100km. And also what Schwepps said is absolutely right. So.... you better change your e90 325i to a e92 335i :wink: hahaha...

 

[glock_8]

:106:

Your statement is totally off if you understand the chemistry of gasoline and the mechanics of combustion engines. Anyone who wants to pay extra to get the same product is perfectly entitled to. It happens all the time.

i never go through this subject in depth....but from simple understanding..higher the octane rating...more difficult to combust...suitable for high compression engine since the fuel will not combust prematurely....

when the factory specified thier optimum power derived from ron 98 to yield 218hp then i reckon any ron lower than that would render changes to the engine timing to replicate a lower compression engine to avoid pre mature combustion...so the lower the compression (for na) the less power it produces..its no doubt the car can still run...but not at the rated power anymore.

as for turbocharged engine, it will have lower compression ratio since it is a force fed. if you tweak the boost (more than the standard manufacturer tune) then u have to lower the compression by changing to thick metal gasket etc.

am i right or just confused

 

[Schwepps]

Firstly, RON is not an indication of the power of a fuel. It is only a measure of the combustibility of a fuel. The higher the RON, the less combustible. A base fuel is dosed with antiknock agents at the point of loading into a road tanker. Ie, the base fuel in the tank farm is homogeneous, and only becomes RON92, 95 or 97 at the tanker pump. In some countries, mixing is even done only at the petrol station.

How RON affects your car's power output: An engine is designed with an optimum spark timing point at a certain crank angle before top dead centre (BTDC) called the 'advance'. This allows the fuel to ignite and achieve full burn at a certain optimum crank angle after top dead centre (ATDC) At this optimum point, the piston is just starting its downstroke and the full burn gives a maximum push. If your anti-knock sensor hears knocking, it will retard the spark point, resulting in full burn occuring past the optimum ATDC point, resulting in a weaker push. If there's no knock, there is no timing retard, and so NO LOSS OF POWER, whether the fuel is 98, 97, 95 or 92. Mass market cars have no knock sensors, so it makes no difference to their engines whatever RON is used.

Modern engines do not knock easily because of advances in cylinder and valve inlet design to eliminate hot spots and introduce swirl of the air-fuel mix. If anyone tells you his car knocks using 95, he's only telling you his engine is old-fashioned or poorly designed.

Knock is caused by high compression and temperature. Turbocharged engines have a higher tendency to knock than normally-aspirated engines because forced induction INCREASES compression, and compressed air is at higher temperature. That's why some cars have intercoolers to reduce the air-fuel temperature. But again, in a sophisticated engine, even a turbocharged engine should not knock using 95. It should only happen with non-factory designed aftermarket slap-ons where the design parameters are not considered at all.

Phew!

 

[infinityKL]

hi schwepes,

i really want to thank you for taking the time and trouble to explain things..

thank you sir cheers

 

[Schwepps]

No problem sachs. Just that I can't stand to know there's so much misconception out there, and have to put things right. BTW, no offence bro, but I'm sure modern Alfas don't knock. Only old bangers do. For some really old bangers (like classic cars) designed for leaded petrol, even RON100 isn't enough and they have to add a can of aftermarket anti-knock to prevent damage to their engines.

 

[ALBundy]

:106:

as for turbocharged engine, it will have lower compression ratio since it is a force fed. if you tweak the boost (more than the standard manufacturer tune) then u have to lower the compression by changing to thick metal gasket etc.

am i right or just confused

Glock,

There are two types of compression ratio, first is the static compression which is your engine's compression ratio, for most BMWs it is 10.5 to 1 (325s) 10.2 to 1 (328s) and etc.

The Japs like to lower the compression and have high turbo boost, to increase the effective compression (there are plenty of sites where you can calculate your effective boost), ie; key in your static compression and boost level and it will give you the effective compression.

The Europeans, usually go the different route, high compression engines 10.5 to 1, with lower boost. The Golf GTi, BMW's 335i all have high compression engines with a boost from 0.8 to 1 bar. This is more fuel efficient as the high compression engines inherently produces more torque and hp.

I have seen many folks lower their compression in order to increase the boost level, but its a double edged sword as the higher boost level will need to overcome the lower static compression, let alone the lose of low end torque before the turbine kicks in.

Cheers