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Old 16th September 2009, 16:57   #31
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Originally Posted by Turbo Head View Post
Deto ??? I could not understand what you mean to say, Please elaborate.
deto = detonation = knocking = uncontrolled combustion of air/fuel mixture in the cylinders. at the end of the day this is what will cause engine damage. as long as it isn't happening/engine is running smooth, then my guess is that the ECU/knock sensor is doing it's job and the owner can feel safe. if it helps, try filling up only shell premium perhaps.

here's the ever helpful wiki link which will explain it in detail:
Octane rating - Wikipedia, the free encyclopedia

"Higher octane ratings correlate to higher activation energies. Activation energy is the amount of energy necessary to start a chemical reaction. Since higher octane fuels have higher activation energies, it is less likely that a given compression will cause detonation.

It might seem odd that fuels with higher octane ratings are used in more powerful engines, since such fuels explode less easily. However, an explosion is not desired in an internal combustion engine. An explosion will cause the pressure in the cylinder to rise far beyond the cylinder's design limits, before the force of the expanding gases can be absorbed by the piston traveling downward. This actually reduces power output, because much of the energy of combustion is absorbed as strain and heat in parts of the engine,[citation needed] rather than being converted to torque at the crankshaft.

A fuel with a higher octane rating can be run at a higher compression ratio without detonating. Compression is directly related to power (see engine tuning), so engines that require higher octane usually deliver more motive power. Engine power is a function of the fuel, as well as the engine design, and is related to octane rating of the fuel. Power is limited by the maximum amount of fuel-air mixture that can be forced into the combustion chamber. When the throttle is partially open, only a small fraction of the total available power is produced because the manifold is operating at pressures far below atmospheric. In this case, the octane requirement is far lower than when the throttle is opened fully and the manifold pressure increases to atmospheric pressure, or higher in the case of supercharged or turbocharged engines.

Many high-performance engines are designed to operate with a high maximum compression, and thus demand high-octane premium gasoline. A common misconception is that power output or fuel mileage can be improved by burning higher octane fuel than a particular engine was designed for. The power output of an engine depends in part on the energy density of its fuel, but similar fuels with different octane ratings have similar density. Since switching to a higher octane fuel does not add any more hydrocarbon content or oxygen, the engine cannot produce more power.

However, burning fuel with a lower octane rating than required by the engine often reduces power output and efficiency one way or another. If the engine begins to detonate (knock), that reduces power and efficiency for the reasons stated above. Many modern car engines feature a knock sensor – a small piezoelectric microphone which detects knock, and then sends a signal to the engine control unit to retard the ignition timing. Retarding the ignition timing reduces the tendency to detonate, but also reduces power output and fuel efficiency.

Most fuel stations have two storage tanks (even those offering 3 or 4 octane levels), and you are given a mixture of the higher and lower octane fuel. Purchasing premium simply means more fuel from the higher octane tank. The detergents in the fuel are the same."

Last edited by silver_shadow : 16th September 2009 at 17:03.
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Old 16th September 2009, 17:46   #32
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Here is a simpler solution to your problem: Octane boosters, if in case you do not find 97 octane fuel you can get the octane boosters from here:

OWS Vitamins for your car
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Old 16th September 2009, 18:07   #33
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Not all customers are supposed to be technically sound. The prime responsibility of selling a product suitable to local conditions rest with manufacturer. How can they sell a car at a place where the required fuel is not available.

I think a case should be filed in consumer court against Skoda for above reason and full refund should be demanded.
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Old 16th September 2009, 21:27   #34
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@silver_shadow : There is a limit to which spark can be retarded. Knock sensors cannot make an engine run on kerosene.
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Old 17th September 2009, 01:23   #35
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@silver_shadow : There is a limit to which spark can be retarded. Knock sensors cannot make an engine run on kerosene.
sure - hence the advice "IF he isn't noticing detonation"... without him telling us we can't know for sure unless we see for ourselves so no point in jumping to conclusions either way.
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Old 17th September 2009, 07:36   #36
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to ensure that the car is able to run - i am sure you friend will know someone who owns a petrol pump and can source RON97 fuel. Once the car is running, through this- take this up with the consumer court - simply because this is a blatant disregard for consumers post purchase.

Dell lost a case yday and was asked to compensate $4Million for "Fraudulent and deceptive business practices" Dell fined $4m in New York fraud scandal - V3.co.uk - formerly vnunet.com

This seems to be another reason not to buy a Skoda? why are they on this self destruction mission?

Edit: ironically- the advert that is being displayed on the page is that for a Skoda! :
Problem with Skoda Superb 3.6 V6 FSI Petrol-picture-4.jpg

Last edited by madan80 : 17th September 2009 at 07:51.
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Old 18th September 2009, 10:07   #37
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Quote:
Originally Posted by Psycho View Post
Here is a simpler solution to your problem: Octane boosters, if in case you do not find 97 octane fuel you can get the octane boosters from here:

OWS Vitamins for your car
Octane boosters will void the warranty, see first page with scanned manual which clearly states the same

Quote:
Originally Posted by akj53 View Post
Not all customers are supposed to be technically sound. The prime responsibility of selling a product suitable to local conditions rest with manufacturer. How can they sell a car at a place where the required fuel is not available.

I think a case should be filed in consumer court against Skoda for above reason and full refund should be demanded.
We are taking a legal opinion for this case.

Quote:
Originally Posted by ImmortalZ View Post
@silver_shadow : There is a limit to which spark can be retarded. Knock sensors cannot make an engine run on kerosene.
Very True, moreover we don't want to loose on performance as well, which is the solo motive for buying a petrol V6.

Quote:
Originally Posted by silver_shadow View Post
sure - hence the advice "IF he isn't noticing detonation"... without him telling us we can't know for sure unless we see for ourselves so no point in jumping to conclusions either way.
We have not driven the car much due to non-availability of the desired fuel, so not having much idea about the detonation.
Can you please help us to identify the "detonation" ?

Quote:
Originally Posted by madan80 View Post
to ensure that the car is able to run - i am sure you friend will know someone who owns a petrol pump and can source RON97 fuel. Once the car is running, through this- take this up with the consumer court - simply because this is a blatant disregard for consumers post purchase.

Dell lost a case yday and was asked to compensate $4Million for "Fraudulent and deceptive business practices" Dell fined $4m in New York fraud scandal - V3.co.uk - formerly vnunet.com

This seems to be another reason not to buy a Skoda? why are they on this self destruction mission?

Edit: ironically- the advert that is being displayed on the page is that for a Skoda! :
Attachment 192963
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Old 18th September 2009, 11:23   #38
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You'll hear a metallic pinging noise from the engine. This is called knock.
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Old 18th September 2009, 12:20   #39
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Originally Posted by Sahil View Post
I face a similar problem but I blame no one but myself for not having looked into this earlier that the car requires 95 Octane. Although I have the 1.8 Superb that I has been running fine on 91 petrol for the past 2500kms but I am sure the ECU has detuned itself and probably not delivering the promised 0 to 100km/hr in 8.5 seconds. Even in a big city like Bombay it's not as easy to find a higher octane fuel pump.
I suggest you friend uses octane boosters, do some research as most don't work but with trial and error he should get it sorted.
GTO- can you check with your skoda contact of the 1.8 engine can handle 91 with detune over a long period? I don't see why not as most RS's have run fine with 91, ofcourse without getting the full engine juice.
i second that, GTO i would love it if you can find out for us, as i own a 1.8tsi laura & skoda told me the same thing to use 91 octane unleaded fuel, please ask your skoda contact if it will do or should i stick to speed97 octane, thanks.
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Old 18th September 2009, 19:44   #40
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Originally Posted by Berj79 View Post
i second that, GTO i would love it if you can find out for us, as i own a 1.8tsi laura & skoda told me the same thing to use 91 octane unleaded fuel, please ask your skoda contact if it will do or should i stick to speed97 octane, thanks.
Quote:
GTO- can you check with your skoda contact of the 1.8 engine can handle 91 with detune over a long period? I don't see why not as most RS's have run fine with 91, ofcourse without getting the full engine juice.
I've been informed that while the engine can comfortably run on 91 octane, it is better (and recommended) to use 95 whenever available.
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Old 19th September 2009, 14:19   #41
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Thanks for the help GTO,
@sahil & OP have you guys checked the inside of your fuel Lid, over there its mentioned the grade of fuel to use in the car, please check guys..
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Old 20th September 2009, 07:00   #42
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Simplistically, the manuals reference to use of ocatane for skoda Superb V6 FSi, is based on the reality that in india, fuel delivered through pump-stations is usually adultered.Since, adultered fuel could in the long run harm this FSi engine, the company has deliberately asked buyers to buy speed 97 or XP or high octane so as forestall the possibility of any damage resulting from adultered fuel.AS in india, the logic is: the Pricier the fuel , the probability of it being adulterated: less!.

But, then the above reason is merely simplistic.

Someone, here compared Honda V6 with Skoda superb V6 FSi.I dont think the comparison is legitimate. The Honda doesn't have the kind of 3 stage injection process that skoda superb V6 has thanks to Fuel stratifed injection(FSi).No matter how many cylinders Honda accord V6 disables in a low load condition , compared to Skoda V6 FSi , it still cannot attain that Ultra Lean mixture that skoda V6 FSi is capable of especially in Ultra Lean Burn mode, that skoda's FSi engine is capable of not Honda's engine.
An instance, shall be suffice.At red light, both Honda V6 and skoda superb V6 FSi standing , low load condition and A/C Off. Honda's engine might have disabled 3 of 6 cyclinders but still the injection is taking place at injection stroke in other 3, whilst, in skoda V6 FSi injection is not taking place in injection stroke but in compression stroke to main its stage 1: Ultra lean burn. Both, doing thier bid for FE but in different ways.
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Old 3rd January 2010, 05:30   #43
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Speed97 has been discontinued guys, now everyone with high compression engines have to depend on octane boosters..
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Old 3rd January 2010, 09:50   #44
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A few more macro issues that I take away from this thread:

(a) the fact that Skoda does not bother to detune its cars for India to run on more widely available 91 RON like almost every other manufacturer does is quite apalling and reinforces (in my eyes) their general apathy towards their customers.

(b) if Skoda's official position firmly stands that it should only be used with 95 RON, then such a conditionality ought to be picked up in homologation related tests (do these apply for locally manufactured vehicles too or just imports. If not, is there some equivalent certification which should pick up on these kind of things?). Skoda should not be permitted to sell a car that as per Skoda's own admission runs only on a fuel quality that is not available all over the country. Even if permitted, it should only be allowed for sale in cities which have the required fuel. Such a significant (and slightly unique) product use limitation should also mandatorily be made known at the dealerships. While at a realistic level I agree GTO that one should do one's research, it still doesn't take away from the manufacturer's obligation to highlight such limitations. Also, you only get access to the user manual after purchasing the vehicle, so even if you read it then diligently cover to cover before even cranking your new car, its already too late.

I know some of the expectations above are a little idealistic but what the hell. BMW had a hell of a time homologating their run flats, I can't believe Skoda can get away with this kind of stuff so easily.

To me, an action in a consumer court in your friend's case might be strong on merits.

Last edited by Axe77 : 3rd January 2010 at 09:51.
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Old 3rd January 2010, 19:26   #45
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Quote:
Originally Posted by Turbo Head View Post
It has been clearly stated in the manual that the fuel should be Petrol ron97/95 only, the same has been confirmed their mail as well.

I have asked him to post the exact mail as well to have better clarity on the subject.

As far as other Skoda cars are concerned, it is not universal (or printing error for India), As for Skoda Octavia RS it suggests Petrol ron 91, same is for Octavia and Laura. So I guess that the issue is with Skoda Superb V6 only.
EXACTLY ! turbo head , what you are saying is very true . let me point out another model with this same issue. that is AUDI A4 3.2 TFSI .same thing here and the sevice book clearly tells you to use 95 ron fuel only though any AUDI dealer will order the car for you irrespective of where you stay.
its only when you point it out , they bother to tell you ,but the ans are always in state of two minds . nothing gets clear by those ans as they are willing to give on their risks but not on companies . and company stats clearly that use 95 ron . so incase something happens its always gona be your fault ! thats why i did cancell the purchase of that otherwise i was so much in to buy that 3.2 that my id also reads quattro A4! but did cencell it over the same issue!
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