reasons for not buying supermarket fuel

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reasons for not buying supermarket fuel

i just explained how.. the ECU uses knock sensor to figure out where optimal spark timing is, and so the ECU adjusts and fires the plugs at that time. I'm sure the worlds motor industry aren't too keen on being represented with such big sweeping statements.

exact spark timing will allow for more efficent burning, better fuel usage and more power.
That assumes you're getting knocking though, if the car is standard and properly set up for 95, you wouldn't need higher octane. If a car doesn't knock at all with 95 fuel, the benefit of using anything above it is non-existant.

Not sure about running temperature lowering to be honest - if it's true, will have a think.
 
the temperature thing is something from experience.

re ECUs though. they are not mapped to strict configurations and locked. they are adaptive. they use sensor information to construct correction maps that are applied to the fuel/spark maps. a modern ECU will adjust its timing to suit conditions, one of these conditions is knock. It will 'look' for knock and then back away from it. Just because it was setup from the factory for 95 ron doesn't mean it won't still do this, and it will find it can run slightly more aggressive timing and still be within knock tolerances.
 
Hang on guys, your ECU has a knock sensor so it can deal with all grades of fuel. A car sold in eastern Europe might not have 95 ron availabe, but can run on 91 ron [which it can but at reduced power]. It also can run above this with altered settings. Super unleaded burns much better then unleaded because its better refind. Your engine will run better and at reduced temp within the head. But a power increase is not likely unless its turbocharged. A bigger bang within the combustion chamber will enhance the exhaust stroke for a turbo and so give a marked increase in power and torque. As measured on a rolling road by 5th gear, it put over 20bhp onto a scooby just by running it on Shell Optimax [now V power]. Ive used Shell V power in my Coupe turbo, and it definately runs better with increased power. But ive tried it in my Passat, and there is no difference to supermarket unleaded.

Andy.:)
 
I don't use supermarket petrol any more because the last time I did my car ran like a bag of s*ite, loads of people have problems with supermarket petrol, theres no smoke without fire:slayer:
 
My mum filled her Hyundai Coupe up from morrisons today and it cut out twice while sat at the lights, this was only in 5 miles as well, I suppose it will get worse once the fuel gets through the system :mad:

Told her not to buy it from there :bang:
 
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well naturally i only use Tesco fuel and I have never had any problems whatsoever. However, I have not filled up for over a week so may have missed the contaminated batch (if indeed there is any).

as for 99RON i thiunk you'll find that Tesco are rolling this out nationally after it received great acclaim from the press so it should be at a petrol station near you soon.
 
This just been on the news......

Tests show suspect petrol blamed for thousands of breakdowns meet British standards, Trading Standards officials say.

Experts are now carrying out further checks to try and solve the mystery.
 
As I said, bet it's an urban myth! Cars always fail, as do lambda sensors, just a few more than normal and suddenly everybody and their dog reports their car isn't running right :D
 
Now they have found silicon in some petrol tanks. This will def mess your ecu up. First official findings will be issued this afternoon.

Andy.
 
Sillicone damages the lambda and traditionally gets in through anti-freeze I do believe, or some seals. This was reported last night after the amazing BBC article saying drivers believed they had ethanol in their petrol *giggles*; nice reporting BBC.
 
Sillicone damages the lambda and traditionally gets in through anti-freeze I do believe, or some seals. This was reported last night after the amazing BBC article saying drivers believed they had ethanol in their petrol *giggles*; nice reporting BBC.

Silicon, not Silicone. Different things.

Andy.
 
Silicon being elemental, silicone being polymers of silicon...it's actually silicone they have found, not silicon as you say, which would be very unlikely since it's not very often elemental without some effort. Either way, it's irrelevant, both will ruin your lambda.
 
I reckon they've used a a tanker for transporting deisel, then petrol and have'nt washed it out properly.
 
You know I doubt they swap tank uses very easily, same with storage tanks. I do not know yet when silicone is added to the mix and all my friends at oil companies don't know either, if it is fairly downstream I would suggest user error.

Another point is that they do not say that the petrol contains some diesel, obviously a requirement to have more than PPB of silicone in the blend. I do not believe that a few litres in a transporting truck would do it.

It may even be a oil refinery mess up.
 
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