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Old 21st August 2007, 11:55   #151
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My experience:

Recently i went for a long ride, I used Shell "Super" while going(dint find any great diffrence) but while coming back i filled Relaince "premium" fuel i did find bike running much smoother.

Guess need to re test it and confirm.
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Old 21st August 2007, 12:06   #152
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Originally Posted by jalsa777 View Post
thanx..i was always wondering why my innova give so much black smoke.

but Shinrai toyota never said anything when i complained about the excess exhaust gasses.
infact they told me to use premium fuel. even i had the black smoke problem. when i sent it to them they had to flush the exhaust and change some turbo components. all under warranty. now my innova dosent even smoke at 4000rpm. its been 6500kms since this happened.
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Old 25th August 2007, 02:07   #153
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Originally Posted by rks View Post
I have started using Speed 97. My Santro handles this fuel with no problems. The power and pick-up are about same as with unadulterated Speed (see my previous post).
After 3 tankfulls of Speed 97, I can safely assert that it is marginally superior to normal Speed. The pickup has improved, the engine is smoother and the top speed has gone up slightly. Today on the way to Mumbai on the Expressway, my Santro was really ripping, hitting 145-150 kmph on several occasions and nearly 160 kmph on the downward sloping stretch just after the Lonawala ghats near the Khalapur toll gate on Mumbai side; AC was switched off on the Expressway. It is a long time since I have felt such a surge of power from my Santro. An Innova guy doing close to 150 kmph after the exit toll gate must have got the surprise of his life when he saw my Santro keeping up in his rear-view mirror. He eventually let me pass in thick traffic.

I think I now have all the "mods" I will ever need; 5J alloy wheels, stock-size tubeless tyres inflated to 35 psi, and Speed 97. It is a potent combination already.

I strongly recommend Speed 97 for those who have MPFI engines and who are allowed to use premium fuels; if my old Santro can handle 97 octane fuel (and actually love it), so can almost any modern MPFI engine. One needs to persist for 2-3 tankfulls to see the full effect. The old fuel needs to get flushed out and the ECU may need some time to make the adjustments.
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Old 25th August 2007, 10:58   #154
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Default Composition of premium fuels

Somewhere here earlier too I posted on the same subject and am repeating once again. Why is it that the oil companies do not disclose the additives they add to their premium fuels?

The least they could do is to let the consumer know as to what other chemical is going in the innards of his/her vehicle.
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Old 25th August 2007, 11:31   #155
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Originally Posted by VC12
System G is sold across most of the IBP filling stations costs around 220-250rs.
Primarily in BP outlets. Have also seen this in Indian Oil outlets. So, best would be to show your old bottle to the pump attendant and ask him if the pump has it.
Originally Posted by Sam
As expected the Skoda dealership will not issue an official statement stating that as the cause of the failure
So, Skoda's also getting localized ... Isn't it B.S? Either they need to issue an official statement that they have tested the ill-effects of premium fuels and premium fuels harm the vehicles they manufacture, Or they replace the part.

AFAIK, using premium fuels will help an engine upto a certain point. The advantages of using premium fuel will not be the same on all engines. But no way would a pump blow up just because one used premium fuels. If that was the case, the oil companies would not have been selling premium fuels in first place.

I have tried premium diesels in both our Tata's - and both are better with the stuff. Smoother engine, better FE, no loss of power.

Last edited by condor : 25th August 2007 at 11:40.
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Old 7th September 2007, 17:30   #156
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Default Difference between speed/premium/unleaded


Am little curious to know the difference between speed / premium / unleaded petrol.

Speed and premium claims higher mileage and better speed then unleaded petrol is it true?

Does it harm the engine in anyways?

Is it ok to mix this petrol incase am using speed and at the next pump i dont get speed, only premium/unleaded is available?

Am sorry if i sound stupid.


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Old 20th September 2007, 20:20   #157
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even BMW says to use only regular unleaded fuel
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Old 23rd September 2007, 23:43   #158
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I think many times we tend to judge the efficacy of premium fuels (or lack of it) without analyzing our individual fuel usage/car specific legacy.

To me, unless the manufacturer recommends otherwise, premium fuel may be used, however, I would use this checklist first -

a. Have we stuck to the recommended octane rating consistently?
b. If we are switching from ordinary to premium, are we going to maintain the octane rating?
c. How long was it since we have been using ordinary fuel? Is there risk of sludge, sediment buildup from ordinary fuel? If so, could the additives from premium fuel actually "clean" these deposits but let them lodge in other engine parts thus threatening malfunction? E.g. the sludge from fuel pump could be dissolved and transported to the high temperature zones where the heat and combustion could convert these dissolved elements to new residual byproducts and lodge them in more vulnerable areas.
d. Do we want to set expectations around how long we want the engine (ECU, etc.) to take to come to terms to the fuel switch, before we begin measuring FE and performance?
e. If we discover performance/FE improvement with premium fuel, what is the speed/gear region where it is most appreciated? E.g. do we see better start/stop performance or do we see power buildup with RPM progression or both? Is it different from what used to be belted out earlier with ordinary fuel?
f. If FE is not appreciated/reduced, is it because there used to be more "pure" fuel per litre in ordinary type and now some of the millilitres are actually the additives and not fuel (which means you are giving your car less fuel per tankful although the volumetrics are the same)?

Generally I believe that an engine that has always combusted premium fuels since it began service has less risk of fuel additive induced component failure, however, the failure risk may be somewhat elevated with alternate use of ordinary and premium fuels.

My 2p.
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Old 5th November 2007, 21:11   #159
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I have got a question to all you forum members in this regard. More specifically, pertaining to the use of XtraPremium petrol in a carb Maruti 800.

You see, I have been using Xtra Premium on my Maruti for the past year or so. With Xtra Premium I find that the engine is a lot smoother, and I am getting better mileage as well.

However, I have a problem with my car now. For the past week or so, the car has started knocking sooo much that it is almost undriveable now. This happens even when the engine is well warmed up. A colleague of mine at work had the exact same syptoms that I am now having on his Honda Unicorn bike, and when he took it to the service center, the first question that they asked him was whether he was using XtraPremuim fuel for his bike. When he replied in the affirmative, they straightaway told him that that was the problem , and to fix it would require cleaning the carburretor, and draining the tank, then filling it with 'normal' petrol.

What I need to know now is, would a carb cleaning solve my problem too? And more importantly, does using Xtra Premium on the carbed maruti somehow lead to deposits in the carb which would require frequent cleaning? Of course, my car has run close to 95K kilometers, and I have done no work on the engine so far, and since this problem only cropped up in the last week or so, I am led to beleive that the carb is at fault here, and would need to be cleaned.

Any suggestions on what to do will be appreciated.
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Old 2nd January 2008, 11:07   #160
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Default Problem with Shell Extra Diesal

I've been a long time user of Shell fuels -- both petrol and diesal.
Like most T-BHPians, I too used to swear by Shell -- till 2 weeks back.

For the past few months, the Shell outlets in Whitefield area have stopped selling normal diesal and only sell Shell Extra -- costing approx. Rs. 2 more per litre.

After 3 tankfulls, I started getting severe knocking on my CRDe Scorpio -- to the extent it was even knocking in 1st gear. Mine is a 2 year old vehicle done just around 22K kms.

The Southern Motors (India Garage) Mahindra service centre in Whitefield told me that this problem was due to use of Shell Extra diesal and advised me to clean the fuel-injectors. The service supervisor also told me that he had seen quite a few Scorpios come in with similar problems after filling up with Shell Extra. Another colleague in office had also reported similar problems with his 6 month old Scorpio, but the problem went away after 2 tankfulls of normal diesal (BPCL). The SM service guys were also insisting that no premium fuels should be used as they foul up the CRDe injectors.

I was charged Rs. 800 for the injector cleaning -- which took almost 5 hours. Now, the knocking has disappeared and my Scorpio is back to it's old self.

I wrote to Shell India via their website, and this is the reply I got

"I clearly understand what problem you faced and also with our knowledge I can anticipate it as a part of the engine cleaning process, one of the main role of Shell Diesel Extra is to protect and keep your engine clean.

If there are carbon deposits already present inside the engine, Shell Diesel Extra is designed to clean it thoroughly due to which your engine could have blocked, our fuel is designed to clean rotary fuel pump and clean the fuel injectors as well.

After extensive road testing done for more than half a million kilometres shell scientists have carefully measured and tested the cleaning power of Shell Diesel Extra for over six months.carried out in real road conditions.

Here what I can understand is as a process of engine cleaning you might have faced this problem,we recommend you to kindly continue using Shell Diesel Extra as it would give better engine performance and it would protect your car's engine now,If you start using any other fuel it might add up to the carbon deposits in the engine.whereby you may not be able to enjoy the benefits provided by our fuel."
This explanation is nonsensical -- which I pointed out to Shell India. A car which has run only 22K kms, AND which has been serviced every 5K kms, does not have carbon deposits build-up so quickly.

Besides, my car ran exclusively on Shell diesal in Bangalore (90% of the time) and only on BPCL normal diesal when I went out of Bangalore. Given that the majority of the time it was running on Shell diesal (filled either at the Brookefields or the Varthur pumps), then the carbon deposits -- if any -- were caused by Shell's own diesal!

Predictably, there had been no further communication from Shell India after my last message to them (Dec 20th).

I am now running with normal diesal (IOC) and am not going anywhere near a Shell pump ever again. BTW, this represent a break of almost 4+ years of almost exclusively filling from Shell -- right from the time they started on Vittal Mallya Road in Bangalore.

Writing this rather long mesasge to warn all T-BHPians. This has been my experience, so I leave it to you to decide whether you want to continue with Shell Extra Diesal or not.

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Old 2nd January 2008, 12:22   #161
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Hi PVGM, my $0.02...

I'm not sure about Shell, but I've been using Speed 97 exclusively since it's introduction. The pamphlet that was initially circulated when Speed was introduced mentioned that the premium fuels contain additives & detergents that displace impurities in lesser fuels.

In fact, I remember reading that switching to the premium fuels should be done on an almost empty tank, & that after a switch, the fuel filter should be changed & the injectors cleaned (due to increased sludge build-up).
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Old 2nd January 2008, 12:41   #162
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Default That's very expensive !

Originally Posted by im_srini View Post
In fact, I remember reading that switching to the premium fuels should be done on an almost empty tank, & that after a switch, the fuel filter should be changed & the injectors cleaned (due to increased sludge build-up).
Well, my fuel-filling cycle is usually just-before-reserve to full tank and back.
Also, I believe fuel filters are usually replaced at every 5K kms service by Mahindra -- and my car goes through a service with SM Garage every 5K kms.

Also, how do you reconcile the SM Service Supervisor's statement that multiple vehicles on Shell Extra Diesal have reported the same problem?

If you recall, there were widespread problems reported about 4-5 years back in Bangalroe with vehicles using Speed 97. It had even come in the papers -- most affected were Zens and Honda City's (OHC) which had their electronic fuel pumps damaged. As I recall, the problem was traced back to faulty mixing of additives at the Mangalore refinery. I suspect Shell has the same issue with their Extra Diesal -- but they are just not willing to admit it. That's why they backed off when I confronted them with the facts I detailed in my previous post.

Anyways, I've learnt my lesson. No more paying Rs. 2 more per litre, AND paying extra for repairing my engine after that !

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Old 24th March 2008, 16:58   #163
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Default Some fuel specs

been browsing all the fuel threads for the last few days now...especially since i paid a whoopping 59.xx for shell super on my swift vxi.

my 2 bits:
  • original octane (RON) rating of the fuel (ie without adding octane boosters - - thanks Shan2nu) greatly affects overall engine performance esp if comp ratio is 9 and above
  • according to BS III norms that apply in 13 major cities across India, ALL unleaded petrol must have a RON of at least 91, so 87/88 is out
  • when filling speed, shell super, xtra premium....its the same fuel with the same RON but diff additives, eg G5 in shell. its effects differ from engine to engine. use and learn seems the only mantra
  • personal experience - shell provides the smoothest drive & best mileage; speed gives slightly more power on tap but def increases knocking; moving to IOC now based on word of mouth reccomms
  • i've included the specs for speed and xtra premium under test conditions off their websites
  • http://www.iocl.com/Products/GasolineSpecifications.pdf
  • Unleaded motor gasoline
  • the marketing comm manager at IOC Mum (Mr Amrish Kapoor - 26447547) is mailing me further info, and i'll upload it if relevant
regardless of the brand u fill...the bunk u fill at remains the most imp factor due to inconsistent fuel quality, exception being shell
hope that helps....someone!
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Old 24th March 2008, 20:01   #164
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After Shell super price increase from 54.XX I moved away from it and tried IOC normal, Extra Premium, BP speed but I can see Shell is best fuel but 59.XX is too costly. In vijaynagar area I couldnt find any good bunks still :( except Shell.


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Old 24th March 2008, 20:25   #165
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Diesel i've found Essar better, Our Safari runs so smooth and returns a nice FE

Petrol, never had probs with any fuel other than shell-low mileage high cost.

Different fuels i feel is not debatable becoz our Vehicles are designed to run on these conditions.

Spurious! yes we can debate

On using Speed 97 my M-800 and VW Beetle runs a bit hotter.This surely means engine loosing life. Just stopped using that fuel.

Shell super Petrol- all 3 of our petrol cars never improved on FE or performance (M-800/Matiz/VW Beetle) for over 5 full tank fillings.

Just getting back to using normal IOC and HP, All the petrol cars behaving fine since a year with better FE.

Essar i swear is the best for our 3L Dicor.

Last edited by PAVAN KADAM : 24th March 2008 at 20:30. Reason: add
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