I fancifully think that even the low purposeful growl of the exhaust and the burble, cracks, pops and bangs which I get in Sports mode have improved with the use of XP95 and occasionally XP100.
BHPian shankar.balan recently shared this with other enthusiasts.
A bit of a story below here. But I consider it to be very much on topic.
Ive also attached some pictures as reference for any one who may be interested.
My ten year old Mini Cooper S specifies a minimum Octane Rating of 91 – this is written inside the fuel tank opener lid. I understand that all petrol in India is of Octane Rating 91. (I d love to receive corroboration of this)
This little car runs on the N18 engine which was made by Peugeot and BMW. This is a 1.6 litre high compression turbo charged engine.
I have generally been using Speed from BPCL ever since I bought this car. Apparently all Speed Petrol is of Octane 93. There are some bunks offering Speed 97 notably in Coimbatore and Madras and where I have filled up from time to time, but I haven’t found one in Bangalore. (Id love to have the Octane Rating of Speed corroborated and get some info on locations too if possible). I also use one can of STP Octane Booster with each tankful of petrol. Without fail.
After buying this car I’ve done a great deal of work on it. In fact I have nursed it back to top condition mechanically because with age and low usage and infrequent and lackadaisical servicing, much work needed doing and multiple parts needed repair/ replacement.
In May 2021 I faced some sudden headaches with the compression low warnings, combustion errors on cylinders 3 and 4, terrible juddering and limp mode and engine check light and all. Frightening.
After a bit of diagnosis with the plug in scanner and some juggling and some serious reference and research on various forums, we dismantled the fuel filter which was wickedly clogged and dirty, and found also that one ignition coil had given up. (Thanks to Ajmat for this pointer- he asked me to switch the ignition coils around and see if there was any difference. That’s what helped catch the defective coil)
I used this opportunity to clean the injectors thoroughly, change the oil filter and all 4 ignition coils to some high performance ones along with a set of Iridium Spark Plugs. Also changed the turbo hoses and the PCV Valve membrane and so on.
But all that is a long story for another day.
The main causes for some of these headaches was the quality of fuel in India. Please take a look at my old OEM factory fitted fuel filter’s picture and judge for yourself. One more pointer. I was using a K&N air filter. By its very nature the fins are wider apart and allow a more free flow of air. In our country this will lead to much more impurities also being sucked into the engine and dirty the oil. So when I encountered this set of headaches I switched right back to the OEM Air filter.
As per North American Motoring, the Fuel Filter typically would need changing out at around 30000 miles, which means 45000 odd kilometers. By coincidence my OEM Factory fitted Fuel Filter needed to be changed exactly around this point. But maybe it would be better, in India at least, to reduce the intervals of change, because of our suspect fuel quality.
I used the car nicely till May-June 2022 – loafed around all over the place. Madras, Ooty a couple of times, Coimbatore, Valparai, Hassan and all. I had put around 7000 kms on it when suddenly there was a brief judder and upon plugging in the diagnostic tool there was an error reading saying combustion misfire.
My heart sank. We opened up the spark plugs and coils and thoroughly wiped and cleaned the plugs with petrol and used the air hose on them and sprayed them with Electrical Connector Cleaner. Reconnected everything and the car just ran very well.
We then performed the entire routine servicing work- oil change, oil filter change and all. The car was running clean and smooth.
I was asked then by my mechanic to use a different petrol pump. Robi Mahanta had recommended IOCL XP95 for a while, so I have now switched completely to this. Once in a while I splurge on XP100. Even now I put one can of STP Octane Booster along with every tankful of petrol.
These steps make a definite difference in combustion, fuel burn efficiency and overall performance.
I fancifully think that even the low purposeful growl of the exhaust and the burble, cracks, pops and bangs which I get in Sports mode have improved with the use of XP95 and occasionally XP100.
After all, one has to feed one’s racehorse the best quality of oats and vitamins and feed. Same goes for one’s trusty 4 wheeled steed.
Keyword: Switched to high octane petrol on my Mini Cooper S: My observations